Predicting the distribution of Omalonyx (Mollusca: Pulmonata: Succineidae) species from literature review, museum databases and new sampling efforts in Brazil

Predição da distribuição de Omalonyx (Mollusca: Pulmonata: Succineidae) a partir da revisão da literatura, dados de museu e novo esforço amostral no Brasil

Abstract

Accurate distributional information is crucial for studies on systematics, biodiversity and conservation. To improve the knowledge regarding the geographical distribution of Omalonyx in South America, we present updated information based on data from a literature review, institutional collections and malacological surveys. All this information composed the dataset used to predict species distribution employing the Maximum Entropy Algorithm (MaxEnt). The model was run using data on species distribution, altitude and bioclimatic variables (WorldClim database). The model had consistent performance, and areas presenting similar conditions to areas where the species were recorded were considered areas of occurrence. The predicted occurrence areas included those that were already surveyed and those that are considered potential occurrence areas. The results demonstrate that the genus has widespread distribution in the Neotropical region and occurs in the tropical, temperate and arid regions of South America and Lesser Antilles. Omalonyx spp. were recorded in all South American countries and hydrographic regions. However, in some countries, there were only isolated records (ex: Colombia and Ecuador). Here, we also present the first record of Omalonyx spp. in four Brazilian States (Acre, Rondônia, Piaui, and Amapá). The genus was found in all hydrographic regions within Brazil and among 27 federative unities; it was absent from only two unities (Roraima State and Distrito Federal). This work contributes to the knowledge on Omalonyx spp. distribution and provides an important basis for the work of ecologists and taxonomists.

Keywords:
MaxEnt; niche model; species distribution; Modeling; Succineids; Neotropic

Resumo

A informação precisa sobre a distribuição é crucial para os estudos sobre sistemática, biodiversidade e conservação. Para melhorar o conhecimento sobre a distribuição geográfica de Omalonyx na América do Sul, apresentamos informações atualizadas com base em dados de revisão de literatura, coleções institucionais e pesquisas malacológicas. Toda essa informação compôs o conjunto de dados usado para predição da distribuição de espécies empregando o Algoritmo de Entropia Máxima (MaxEnt). O modelo foi executado usando dados de distribuição de espécies, altitude e variáveis bioclimáticas (banco de dados WorldClim). O modelo apresentou um desempenho consistente e as áreas que apresentaram condições semelhantes às áreas onde as espécies foram registradas, foram consideradas áreas de ocorrência. As áreas de ocorrências previstas incluíram aquelas que já foram pesquisadas e aquelas que são consideradas áreas de ocorrência potencial. Os resultados demonstram que o gênero tem uma distribuição Neotropical ampla e que ocorre nas regiões tropical, temperada e árida da América do Sul e nas Pequenas Antilhas. Omalonyx spp. foram registradas em todos os países e bacias sul-americanas. No entanto, em alguns países, apenas registros isolados foram encontrados (ex: Colômbia e Equador). Aqui, também apresentamos o primeiro registro de Omalonyx spp. em quatro estados brasileiros (Acre, Rondônia, Piauí e Amapá). O gênero foi encontrado em todas as regiões hidrográficas no Brasil e nas 27 unidades federativas; sendo ausente em apenas duas unidades federativas (Estado de Roraima e Distrito Federal). Esse trabalho contribui para o conhecimento da distribuição das espécies de Omalonyx e fornece uma importante base para trabalhos de ecólogos e taxonomistas.

Palavras chave:
MaxEnt; modelagem de nichos; distribuição de espécies; Modelagem; Succineídeos; Neotrópico

Introduction

The genus Omalonyxd’Orbigny, 1837 presents a reduced shell and represents one of the slug-like lineages within the family Succineidae (Patterson 1971, Tillier 1981, Barker 2001). The earliest fossil records of Succineidae were from the Tertiary of Europe and, currently, most of the diversity within the family occurs in the islands of the Pacific, in the Indian subcontinent and the Americas (Barker 2001). These Neotropical slugs are terrestrial, live on aquatic macrophytes or riparian vegetation and can also be found in humid soil (Garcia et al. 2012). They can act as agricultural plagues (Olazarri 1979, Garcia et al. 2012) and are agents in the control of water-cress (Poi de Neiff et al. 1977). They can also act as intermediate hosts of an avian trematode, Leucochloridium (Lutz 1921, Travassos 1928), in the wild and of the nematodes Angiostrongylus costaricensis and A. vasorum in the laboratory (Montresor et al. 2008, Mozzer et al. 2011).

Currently, it is assumed that the genus comprises six recognized species (Tillier 1980, 1981, Martínez 1993, Arruda & Thomé 2008a, b, Arruda et al. 2009, Coscarelli & Vidigal 2011): Omalonyx convexus (Martens, 1868), Omalonyx unguis (d’Orbigny, 1837), Omalonyx brasiliensis (Simroth, 1896), Omalonyx matheroni (Pontiez & Michaud, 1835), Omalonyx geayi Tillier, 1980, and Omalonyx pattersonae Tillier, 1981. However, identification of the species within this genus is greatly complicated by intraspecific morphological variation in the diagnostic characteristics such as the papillae on the internal surface of the penis, the insertion of the retractor muscle of the penis, the shape of papillae on the inner surface of the vagina and others (Tillier 1980, 1981, Martínez 1993, Arruda & Thomé 2008a, b, Arruda et al. 2009, Coscarelli & Vidigal 2011).

To improve taxonomic knowledge on Omalonyx species, studies encompassing morphological and molecular data are essential. However, the first step to elucidating these questions is to acquire knowledge on species geographical distribution. Accurate geographical distributional information is crucial to solve systematics and biogeographic problems and to drive conservation efforts. Species-distribution models infer potential distribution from data on observed distribution and from environmental variables related to the sites where occurrences were recorded (Bradie & Leung 2017). These models assume that climate ultimately restricts a species' distribution and summarize it with a number of climatic variables within the known range of the species, generating a bioclimatic profile. They play an important role as first filters in assessing the potential distribution of each species, improving the success of future sampling efforts and providing initial insight into the bioclimatic tolerance of different species (Beaumont et al. 2005, Rubio & Acosta 2011). These tools have also been applied in several conservation biology studies to identify areas with high species richness and to predict effects of climate change on species’ distributions (Araújo & Rahbek 2006, Costa et al. 2010, Vogler et al. 2013).

There are several methods to model species distribution, and they may use presence/absence, abundance or presence-only data. Usually, species records have limited coverage and consist of presence-only data (Elith et al. 2011). The Maximum Entropy Algorithm (MaxEnt) presents high performance for modeling presence-only data and is widely used to model species distribution (Bradie & Leung 2017). Here, we use this method to improve the knowledge on the geographical distribution of Omalonyx spp., assembling literature data with specimens either collected in our surveys, from malacological collections or donated by partner laboratories. These data on species presence and the associated bioclimatic variables were used to model species distribution, to investigate the main environmental factors related to the occurrence of Omalonyx species and to detect species with overlapping distribution areas. This work improves the knowledge on these slugs' distribution, providing information to propel advances in the morphological and molecular taxonomy of these neotropical succineids.

Material and Methods

Literature data on Omalonyx was reviewed (until December 2016) in order to find records of its occurrence across the Neotropical region (see the topic literature review in the results). Institutions harboring preserved specimens were identified in the literature review and by onsite and virtual searching in institutional collections (Table 1), and information regarding the lot number and collection site was organized in two tables (Table 2 and 3). Donated specimens were also included in these tables (Table 2 and 3).

Table 1
Institutions harbouring specimens of Omalonyx found after literature review, visits and virtual search in collections databases.

Abbreviation	Museum or collection name
ANSP	Academy of Natural Sciences of Philadelphia, Pennsylvania, United States of America.
BMNH	British Museum of Natural History, London, United Kingdom.
CM	Carnegie Museum, Pittsburgh, Pennsylvania, United States of America.
CMIOC*	Coleção de Moluscos do Instituto Oswaldo Cruz, Rio de Janeiro, Brazil.
FLMNH	Florida Museum of Natural, United States of America.
FMNH	Field Museum of Natural History, Chicago, Illinois, United States of America.
INPA*	Instituto Nacional de Pesquisas da Amazônia, Manaus, Amazonas, Brazil.
LMSM	Laboratório de Malacologia e Sistemática Molecular, Belo Horizonte, Minas Gerais, Brazil.
MACN	Museo Argentino de Ciencias Naturales, Bernadino Rivadavia, Buenos Aires, Argentina.
MCP	Museu de Ciências e Tecnologia da Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
MCNZ	Museu de Ciências Naturais, Fundação Zoobotânica do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
MCZ	Museum of Comparative Zoology, Harvard University, Cambridge, Massachusetts, United States of America.
MIRR*	Museu Integrado de Roraima, Boa Vista; Roraima, Brazil.
MLP*	Museo de La Plata, La Plata, Argentina.
MNHCL	Museo Nacional de Historia Natural del Chile, Chile.
MHNG	Muséum d’Histoire Naturelle, Genève, Switzerland.
MNKMO	Museo de Historia Natural Noel Kempff Mercado, Santa Cruz de la Sierra, Bolivia.
MNHN	Muséum national d’Histoire naturelle, Paris, France.
MNHNM	Museo Nacional de Historia Natural de Montevideo, Uruguay.
MNRJ*	Museu Nacional da Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
MPEG*	Museu Paraense Emílio Goeldi, Belém, Pará, Brazil.
MZUM	Museum of Zoology, University of Michigan, Ann Arbor, Michigan, United States of America.
MZUSP*	Museu de Zoologia da USP, São Paulo, São Paulo, Brazil.
RMNH	Rijksmuseum van Natuurlijke Histoire, Leiden, Netherlands
SMNH	Naturhistoriska Riksmuseet, Stockholm, Sweden.
UF	Florida Museum of Natural History (USA).
UFS	Universidade Federal de Sergipe, Aracajú, Sergipe, Brazil.
USDA	United States Department of Agriculture, Philadelphia, United States of America.
USMN	National Museum of Natural History, Smithsonian Institution, Washington, DC, United States of America.
ZMB	Museum für Naturkunde der Humboldt Universität, Berlin, Germany.
ZUECGAS	Museu de Zoologia da Universidade Estadual de Campinas, Campinas, São Paulo, Brazil.

• Visited collections*

Table 2
Records of Omalonyx in Brazil based on literature data, institutional collections, and our own malacological surveys.

Species	Region	Locality	Record	1Source	2Hydrographic Region	Coordinates
O. matheroni	North	Rio Branco, Acre	LMSM 3346, 3378-83, 3438	Survey	5	10º 31'48”S, 68º 18'54”W
O. matheroni	North	Nações Unidas Ave. Macapá, Amapá	LMSM 3205-07, 3216-17, 3144, 3146	Survey	4	0º 28'19.2”N, 51º 39'0”W
O. matheroni	North	Amazon River, Santana, Amapá	LMSM 3199, 3200-03, 3232-33	Survey	4	0º 33'50.4”N, 51ºW 10'35.04”
O. matheroni	North	BR 156 Road, Calçoene, Amapá	LMSM 3215, 3220-21, 3145, 3147	Survey	4	2º 29'44.16”N, 50º 57'14.04W”
Omalonyx sp.	North	Manicore, Amazonas	INPA 445	Museum	4	6º 27'35.28”S, 61º 26'47.4W”
Omalonyx sp.	North	Novo Aripuanã, Amazonas	INPA769, 779, 781, 785, 801, 802, 808 (Pimpão 2007)	Literature	5	6º 49'30”S, 60º 28'37.92”W
Omalonyx sp.	North	Juruá River, Amazonas	MZSP 18444, 31962	Museum	5	2º 44'19.68”S, 66º 45'41.76”W
Omalonyx sp.	North	Barurua Island, Amazonas	MZSP 18445	Museum	5	2º 31'48”S, 67º 21'59.76”W
Omalonyx sp.	North	Amaña Lake, Japurá River Basin, Amazonas	MZSP 31874	Museum	5	2º 35'53.16”S, 64º 39'47.16”W
Omalonyx sp.	North	Boca do Acre, Amazonas	MZSP 31881-83	Museum	5	8º 45'37.44”S, 68º 53'52.8”W
Omalonyx sp.	North	Manaus, Amazonas	INPA 575, 598, 614, 620, 858, 1081; MZSP 31963	Museum	5	3º 6'6.84”S, 60º 15'0”W
O. pattersonae	North	Itacotiara, Manaus, Amazonas	ANSP 109524	Museum	5	_
Omalonyx sp.	North	Marchantaria Island, Amazonas	INPA 522	Museum	5	3º 14'23.28”S, 59º 56'15.36”W
	North
O. geayi	North	Careiro Marchantaria Island, Amazonas	MCNZ 30548 (Arruda et al. 2016)	Literature	5	3º 15'14.11”S, 59º 58'19.09”W
Omalonyx sp.	North	Parana Uauaçu, Amazonas	INPA 532	Museum	5	4º 18'50.04”S, 62º 9'55.08”W
O.matheroni	North	Iranduba, Amazonas	LMSM 2270, 2276-77	Survey		3º 57'7.2”S, 60º 28'50.52”W
O.matheroni	North	Iranduba, Amazonas	INPA 551-2, 870	Museum	5	3º 57'7.2”S, 60º 28'50.52”W
O. geayi	North	Iranduba, Amazonas	INPA 1091 (Arruda et al. 2016)	Literature	5	3º 8'44.4768”S, 60º 15'26.6256”W
O. matheroni	North	Preto da Eva River, Amazonas	LMSM 2260, 2332-35	Survey	5	2º 31'47.64”S, 59º 38'17.52”W
O. matheroni	North	Preto da Eva River, Amazonas	INPA 1090 (Garcia et al. 2012)	Literature	5	2º 31'47.64”S, 59º 38'17.52”W
Omalonyx sp.	North	Preto da Eva River, Amazonas	INPA 1090 (Garcia et al. 2012)	Literature	5	2º 31'47.64”S, 59º 38'17.52”W
O. pattersonae	North	Preto da Eva River, Amazonas	LMSM 2260, 2332-35;	Survey	5	2º 31'47.64”S, 59º 38'17.52”W
O. pattersonae	North	Preto da Eva River, Amazonas	INPA 1090 (Garcia et al. 2012)	Literature	5	2º 31'47.64”S, 59º 38'17.52”W
Omalonyx sp.	North	Carauari, Amazonas	MCP 09184	Museum	5	5º 7'7.68”S, 67º 20'15.36”W
O. geayi	North	Carauari, Amazonas	INPA 1643; MCP 09183 (Arruda et al. 2016)	Literature	5	5º 7'7.68”S, 67º 20'15.36”W
O. matheroni	North		SMNH 1450 (Tillier 1981)	Literature		unespecified locality
O. matheroni	North	-	MHNG 53834.8 (Tillier 1981)	Literature		unespecified locality
Omalonyx sp.	North	Santarém, Pará	ZUECGAS 3313, 3215-3217; MZSP 31885	Museum	5	2ºS 45'52.56”, 55ºW 56'16.8”
O. matheroni	North	Santarém, Pará	LMSM 2573-2579, 2583, 2646-49, 2663, 2670, 2761, 2765-67, 2789-94, 2835, 2849-76, 2910, 2930, 3234-36	Survey	5	2º 45'52.56”S, 55º 56'16.8”W
O. matheroni	North	Santarém, Pará	Lange de Morretes 1949; BMNH 1896.9.33 (Tillier 1981), Simone 2006	Literature	5	2º 45'52.56”S, 55º 56'16.8”W
O. matheroni	North	Alenquer, Pará	FMNH 29190 (Tillier 1981)	Literature	5	0º 32'10.68”S, 55º 41'56.4”W
Omalonyx sp.	North	Almerim, Pará	MZSP 31877	Museum	5	0º 17'56.4”N, 53º 53'37.68”W
Omalonyx sp.	North	Furo do Jurupari, Pará	MZSP 31879	Museum	5	2º 40'37.2”S, 53º 16'48”W
Omalonyx sp.	North	Lago Parú, Pará	MZSP 31959	Museum	5	1º 53'30.12”S, 55º 49'55.92”W
O. matheroni	North	Tucuruí, Pará	LMSM 2569, 2584-87, 2588, 2672, 2915-16	Survey	06/jul	3º 51'20.88”S, 49º 49'14.88”W
O. matheroni	North	Juruti, Pará	LMSM 3151-52, 3168	Survey	5	2º 37'21.72”S, 56º 13'16.32”W
O. matheroni	North	Belém, Pará	LMSM 3230-31	Survey	7	1º 14'26.52”S, 48º 27'33.84”W
O. matheroni	North	Cereja River, Bragança, Pará	LMSM 4037-4043	Survey	7	1º 20'49.2”S, 46º 45'42.84”W
O. pattersonae	North	Cereja River, Bragança, Pará	LMSM 4037-4043	Survey	7	1º 20'49.2”S, 46º 45'42.84”W
Omalonyx sp.	North	Curuá, Pará	ZUECGAS 3204-9, 3210-4, 3218	Museum	7	1º 50'45.24”S, 55º 6'47.52”W
O. matheroni	North	Ji-Paraná, Rondônia	LMSM3360, 3362, 3367	Survey	5	10º 27'43.92”S, 61º 45'25.56”W
O. matheroni	North	Madeira River, Porto Velho, Rondônia	LMSM 3347-48, 3358-59, 3364-65, 3372-76, 3403-04, 3440	Survey	5	8º 46'14.16”S, 63º 54'29.16”W
Omalonyx sp.	Northeast	Malvina District, Arari, Maranhão	MNRJ 6305; CMIOC 9519 (Cantanhede et al. 2014)	Museum	7	3º 27'30.96”S, 44º 46'30”W
Omalonyx sp.	Northeast	Amaral Village, Monção, Maranhão	CMIOC 9409 (Cantanhede et al. 2014)	Literature	7	3º 30'7.92”S, 45º 16'33.6”W
Omalonyx sp.	Northeast	Palmeirândia, Maranhão	Cantanhede et al. 2014	Literature	7	2º 41'34.08”S, 45º 15'0”W
Omalonyx sp.	Northeast	Pedro do Rosário, Maranhão	Cantanhede et al. 2014	Literature	7	2º 59'20.76”S, 45º 25'48”W
Omalonyx sp.	Northeast	Peri-Mirim, Maranhão	Cantanhede et al. 2014	Literature	7	2º 34'18.12”S, 44º 53'43.44”W
Omalonyx sp.	Northeast	Santa Terezinha District, Pinheiro, Maranhão	CMIOC 9452-53 (Cantanhede et al. 2014)	Literature	7	2º 30'55.08”S, 45º 48'7.2”W
Omalonyx sp.	Northeast	Santa Helena, Maranhão	Cantanhede et al. 2014	Literature	7	2º 25'33.96”S, 45º 22'59.52”W
Omalonyx sp.	Northeast	Porto Grande District, São Bento, Maranhão	CMIOC 9471 (Cantanhede et al. 2014)	Literature	7	2º 42'0”S, 44º 49'21.36”W
Omalonyx sp.	Northeast	São João Batista, Maranhão	Cantanhede et al. 2014	Literature	7	3º 27'36”S, 44º 45'32.04”W
Omalonyx sp.	Northeast	Vitória do Mearim, Maranhão	Cantanhede et al. 2014	Literature	7	3º 34'26.4”S, 44º 55'24.96”W
Omalonyx sp.	Northeast	Parnaíba, Piauí	LMSM 4558-64	Survey	7	2º 57'37.8”S, 41º 45'12.96”W
O. unguis	Northeast	Baturité, Ceará	MNRJ 12382	Museum	7	4º 22'49.44”S, 38º 51'10.08”W
O. matheroni	Northeast	Fortaleza, Ceará	LMSM 2027-29, 4579-4580	Survey	7	3º 47'10.32”S, 38º 31'38.64”W
Omalonyx sp.	Northeast	Fortaleza, Ceará	LMSM 2027-29, 4579-4580	Survey	7	3º 47'10.32”S, 38º 31'38.64”W
Omalonyx sp.	Northeast	Redenção, Ceará	CMIOC 5155	Museum	7	4º 14'57.48”S, 38º 45'56.52”W
Omalonyx sp.	Northeast	Sobral, Ceará	LMSM 4581-2	Survey	7	3º 42'54”S, 40º 20'58.92”W
O. matheroni	Northeast	Natal, Rio Grande do Norte	LMSM 2491, 2514, 2537, 2540-41, 3243	Survey	7	5º 48'11.88”S, 35º 13'44.4”W
O. pattersonae	Northeast	Natal, Rio Grande do Norte	LMSM 2491, 2514, 2537, 2540-41, 3243	Survey	7	5º 48'11.88”S, 35º 13'44.4”W
O. matheroni	Northeast	Formosa Bay, Rio Grande do Norte	CMIOC 8569	Museum	7	6º 22'15.24”S, 35º 30'0”W
Omalonyx sp.	Northeast	João Pessoa, Paraíba	MZSP 41365	Museum	7	7º 9'59.04”S, 34º 52'10.92”W
O. matheroni	Northeast	Caruaru, Pernambuco	LMSM 2783, 2837, 2909	Survey	7	8º 10'48”S, 36º 9'54”W
O. matheroni	Northeast	Caruaru, Pernambuco	ANSPA18032- A18038 (Dutra-Clarke et al. 2001)	Literature	7	8º 10'48”S, 36º 9'54”W
O. matheroni	Northeast	Pernambuco	BMNH 1887.9.8.31 (Tillier 1981)	Literature	8	8º 28'56.64”S, 37º 46'21.72”W
Omalonyx sp.	Northeast	Tacaratu, Pernambuco	MZSP 31960	Museum	7	8º 57'24.48”S, 38º 45'54”W
Omalonyx sp.	Northeast	Dois Irmãos Zoo, Recife, Pernambuco	MZSP 31967, 47767-818, 48050	Museum	9	8º 6'0”S, 34º 56'51.36”W
Omalonyx sp.	Northeast	Maceió, Alagoas	MNRJ 32140	Museum	9	9º 31'12.36”S, 35º 42'37.08”W
O. geayi	Northeast	Satuba, Alagoas	ZMB 90832 (Arruda et. al. 2016)	Literature	7	9º 34'23.1924”S, 35º 49'31.8216”W
O. pattersonae	Northeast	Itabaiana, Sergipe	MCP 09276	Literature	9	10º 41'9.24”S, 37º 25'18.84”W
O. convexus	Northeast	Itabaiana, Sergipe	UFS 400, 403 (Jesus & Manso 2010)	Literature	9	10º 41'9.24”S, 37º 25'18.84”W
O. matheroni	Northeast	Tororó Dam, Salvador, Bahia	LMSM 3261-62	Survey	9	12º 59'42”S, 38º 30'22.32”W
Omalonyx sp.	Northeast	Tororó Dam, Salvador, Bahia	CMIOC 9865;MNRJ50523	Museum	9	12º 59'42”S, 38º 30'22.32”W
O. unguis	Northeast	Tororó Dam, Salvador, Bahia	Moricand 1836; Hidalgo 1870, 1872	Literature	9	12º 59'42”S, 38º 30'22.32”W
O. matheroni	Northeast	Vila Nova, Bahia	Lange de Morretes 1949	Literature	9	17º 30'14.04”S, 40º 30'28.8”W
Omalonyx sp.	Northeast	Uruçuca, Bahia	MZSP 18443	Museum	9	14º 30'58.32”S, 39º 13'35.76”W
Omalonyx sp.	Northeast	Campo Formoso, Bahia	MZSP 31880	Museum	8	10º 15'39.6”S, 40º 42'33.84”W
O. matheroni	Northeast	Prado, Bahia	LMSM 2914	Survey	9	17º 7'55.2”S, 39º 21'7.56”W
Omalonyx sp.	Northeast	Esplanada, Bahia	CMIOC 7973	Museum	9	11º 56'23.64”S, 37º 53'10.68”W
Omalonyx sp.	Northeast	Entre Rios, Bahia	CMIOC 8083	Museum	9	12º 43'26.4”S, 38º 25'22.8”W
Omalonyx sp.	Northeast	Wenceslau Guimarães, Bahia	CMIOC 8803	Museum	9	13º 37'49.44”S, 39º 37'36.48”W
O. matheroni	Southeast	Maracás, Bahia	MNRJ 14021, 32138	Museum	9	13º 29'50.64”S, 40º 33'11.16”W
Omalonyx sp.	Southeast	Maracás, Bahia	MNRJ 14021, 32138	Museum	9	13º 29'50.64”S, 40º 33'11.16”W
O. unguis	Southeast	Mocambinho, Jaíba, Minas Gerais	Oliveira & Almeida 2000. CMIOC 4307	Literature	8	16º 6'53.64”S, 43º 58'28.92”W
				Museum
O. unguis	Southeast	Mocambinho, Jaíba, Minas Gerais	CMIOC 4307	Museum	8	16º 6'53.64”S, 43º 58'28.92”W
O. matheroni	Southeast	Caratinga Biological Station, Caratinga, Minas Gerais	Arruda et al. 2006, Montresor et al. 2008	Literature	9	19º 43'21.36”S, 41º 48'21.96”W
O. matheroni	Southeast	Caratinga Biological Station, Caratinga, Minas Gerais	LMSM 711, 712, 714, 731-33, 744-45, 747-48, 763	Survey	9	19º 43'21.36”S, 41º 48'21.96”W
O. matheroni	Southeast	Caratinga Biological Station, Caratinga, Minas Gerais	MZSP 35387	Museum	9	19º 43'21.36”S, 41º 48'21.96”W
Omalonyx sp.	Southeast	Teófilo Otoni, Minas Gerais	MZSP 18442, 31886; MNRJ 18365	Museum	9	17º 42'55.08”S, 41º 23'24”W
O. matheroni	Southeast	Pampulha Lake, Belo Horizonte, Minas Gerais	LMSM 1378-87, 2383, 2516, 2525, 2527, 2529, 2536, 2787, 2918, 2929, 3153-55, 3162-63, 3166, 3186, 3208-10; MCP 09277-9,09192	Survey	8	19º 54'10.08”S, 43º 57'36.72”W
O. matheroni	Southeast	Rio Doce State Park, Marliéria, Minas Gerais	LMSM 1962-68, 2104-06, 2108; MNRJ 18365	Survey	9	19º 38'41.64”S, 42º 32'9.6”W
Omalonyx sp.	Southeast	Rio Doce State Park, Marliéria, Minas Gerais	MNRJ 18365	Museum	9	19º 38'41.64”S, 42º 32'9.6”W
O. matheroni	Southeast	Januária, Minas Gerais	LMSM 2526-27	Survey	8	15º 19'13.8”S, 44º 50'55.32”W
O. matheroni	Southeast	Nova Serrana, Minas Gerais	LMSM 713, 746	Survey	8	19º 51'8.64”S, 44º 58'27.84”W
O. matheroni	Southeast	Ipatinga, Minas Gerais	LMSM 3046	Survey	9	19º 26'20.76”S, 42º 36'14.4”W
O. matheroni	Southeast	Betim, Minas Gerais	LMSM 3079-81, 3097-99, 3101, 3105, 3147-48, 3164-65	Survey	8	19º 56'51”S, 44º 11'57.84”W
Omalonyx sp.	Southeast	Cachoeira Dourada, Minas Gerais	CMIOC 7098	Museum	10	18º 36'25.92”S, 49º 28'48.36”W
Omalonyx sp.	Southeast	Ilha dos Frades District, Vitoria, Espírito Santo	MZSP 31965	Museum	9	20º 18'7.92”S, 40º 16'40.44”W
Omalonyx sp.	Southeast	Serra, Espírito Santo	LMSM 3027 (Donation from CMIOC)	Donation	9	20º 7'41.16”S, 40º 18'6.48”W
Omalonyx sp.	Southeast	Rio de Janeiro, Rio de Janeiro	MNRJ 32143; 9617	Museum	9	22º 55'24.24”S, 43º 26'51.36”W
O. unguis	Southeast	Rio de Janeiro, Rio de Janeiro	Lutz 1921	Literature	9	22º 55'24.24”S, 43º 26'51.36”W
O. unguis	Southeast	Rio de Janeiro, Rio de Janeiro	MNRJ 1916, 2199, 57865, 12378-79; 12381	Museum	9	22º 55'24.24”S, 43º 26'51.36”W
O. convexus	Southeast	Rio de Janeiro, Rio de Janeiro	MCZ unnumber (Parodiz 1963); MNHN, Gaudichaud coll. 1833 (Tillier 1981)	Literature	9	22º 55'24.24”S, 43º 26'51.36”W
O. matheroni	Southeast	Rio de Janeiro, Rio de Janeiro	LMSM 412-16, 3512-16 (Donation from CMIOC).	Donation	9	22º 55'24.24”S, 43º 26'51.36”W
O. unguis	Southeast	Araruama, Rio de Janeiro	MNRJ 12380	Museum	9	22º 45'16.92”S, 42º 17'36.24”W
Omalonyx sp.	Southeast	Parati, Rio de Janeiro	LMSM 419 (Donation from CMIOC)	Donation	9	23º 8'56.76”S, 44º 42'20.16”W
Omalonyx sp.	Southeast	Ilha Grande, Rio de Janeiro	LMSM 420-421 (Donation from CMIOC)	Donation	9	23º 9'7.56”S, 44º 13'44.04”W
Omalonyx sp.	Southeast	Macaé, Rio de Janeiro	LMSM 422-25, 431-32 (Donation from CMIOC). MNRJ30737	Donation	9	22º 17'42”S, 41º 58'29.64”W
Omalonyx sp.	Southeast	Raiz da Serra, Rio de Janeiro	LMSM 417, 426-28 (Donation from CMIOC)	Donation	9	22º 34'12”S, 43º 11'12.48”W
O. matheroni	Southeast	Duque de Caxias, Rio de Janeiro	LMSM 841, 857-58 (Donation from CMIOC)	Donation	9	22º 37'56.28”S, 43º 18'0”W
Omalonyx sp.	Southeast	Pendotiba, Niterói, Rio de Janeiro	CMIOC3877	Museum	9	22º 54'45”S, 43º 42'28.8W”
Omalonyx sp.	Southeast	São Fidélis, Rio de Janeiro	CMIOC 7515	Museum	9	21º 39'36”S, 41º 47'16.08”W
Omalonyx sp.	Southeast	Pinheiral, Rio de Janeiro	MCP 09187-8	Museum	9	22º 32'31.56”S, 43º 59'57.84”W
Omalonyx sp.	Southeast	Lagoa do Campelo, Campos, Rio de Janeiro	MNRJ 32139	Museum	9	21º 39'10.8”S, 41º 9'59.4”W
Omalonyx sp.	Southeast	Carmo, Rio de Janeiro	MNRJ1911	Museum	9	21º 54'7.56”S, 42º 34'8.4”W
O. convexus	Southeast	Campo dos Goytacazes, Rio de Janeiro	MNRJ 30735, 30785	Museum	9	21º 45'44.28”S, 41º 19'44.4”W
Omalonyx sp.	Southeast	Campos dos Goytacazes, Rio de Janeiro	MNRJ 30735, 30785	Museum	9	21º 45'44.28”S, 41º 19'44.4”W
Omalonyx sp.	Southeast	Santo Antônio de Pádua, Rio de Janeiro	MNRJ 32141	Museum	9	21º 33'24.84”S, 42º 11'33.72”W
Omalonyx sp.	Southeast	Itaguaí, Rio de Janeiro	MNRJ 32144	Museum	9	22º 50'29.4”S, 43º 49'12”W
Omalonyx sp.	Southeast	Cambuci, Rio de Janeiro	MNRJ 32148	Museum	9	21º 29'48.12”S, 41º 54'52.2”W
Omalonyx sp.	Southeast	Osasco, São Paulo	MZSP 17071	Museum	10	23º 31'44.04”S, 46º 47'20.76”W
Omalonyx sp.	Southeast	São José do Rio Preto, São Paulo	MZSP 18441, 31878; MNRJ 32137, 14024	Museum	10	20º 47'51”S, 49º 21'29.88”W
O. unguis	Southeast	São José do Rio Preto, São Paulo	MZSP 18441, 31878; MNRJ 32137, 14024	Museum	10	20º 47'51”S, 49º 21'29.88”W
Omalonyx sp.	Southeast	Caçapava, São Paulo	MZSP 31865	Museum	10	23º 6'12.6”S, 45º 42'48.24”W
Omalonyx sp.	Southeast	Barueri, São Paulo	MZSP 31875, 47749-51, 47819-50, 47879	Museum	10	23º 30'18.72”S, 46º 52'35.4”W
Omalonyx sp.	Southeast	Tremembé, São Paulo	MZSP 31876	Museum	9	22º 56'25.8”S, 45º 36'13.32”W
Omalonyx sp.	Southeast	Lins, São Paulo	MZSP 31966	Museum	10	21º 38'58.92”S, 49º 40'59.16”W
Omalonyx sp.	Southeast	Colômbia, São Paulo	MZSP 32664	Museum	10	20º 15'59.76”S, 48º 43'16.32”W
Omalonyx sp.	Southeast	Taubaté, São Paulo	MZSP 45129, 47718-26, 47738-47, 47858-67, 47907-10, 47939-82, 47995-8017, 48049, 48053	Museum	9	23º 52'48”S, 45º 30'7.92”W
Omalonyx sp.	Southeast	Paulínia, São Paulo	MZSP 47727-37, 47752-66	Museum	10	22º 44'51.72”S, 47º 8'41.64”W
Omalonyx sp.	Southeast	Americana, São Paulo	MZSP 47938	Museum	10	22º 43'23.52”S, 47º 17'20.04”W
Omalonyx sp.	Southeast	Santo André, São Paulo	MZSP 32774 (Eduardo et al. 2012)	Literature	10	23º 43'41.88”S, 46º 26'28.68”W
O. matheroni	Southeast	Santo André, São Paulo	MZSP 32774 (Eduardo et al. 2012)	Literature	10	23º 43'41.88”S, 46º 26'28.68”W
O. matheroni	Southeast	Ibitinga Powerplant, Ibitinga, São Paulo	MCP 09120 (Arruda et al. 2009)	Literature	10	21º 45'28.08”S, 48º 59'30.12”W
O. matheroni	Central West	Santa Rita do Novo Destino, Goiás	LMSM 3241-42	Donation	8	14º 52'35.4”S, 49º 33'46.8”W
Omalonyx sp.	Central West	Passo da Lontra, Mato Grosso do Sul	MZSP 41206	Museum	10	19º 34'29.28”S, 57º 22'40.8”W
Omalonyx sp.	Central West	Três Lagoas, Mato Grosso do Sul	MZSP 47748	Museum	10	20º 26'19.68”S, 52º 12'41.04”W
O. unguis	Central West	Campo Grande, Mato Grosso do Sul	LMSM 2747	Survey	10	20º 54'47.16”S, 54º 14'58.92”W
O. unguis	Central West	Miranda, Mato Grosso do Sul	LMSM 2705-07, 2739-42, 2769, 2780-81, 2788, 2797-99, 2898-99, 2900-08, 2911-13, 2917	Survey	10	20º 7'12.36”S, 56º 35'52.8”W
O. unguis	Central West	Transpantaneira Road, Mato Grosso	MNRJ 9969	Museum	10	16º 22'30”S, 56º 40'12”W
O. unguis	Central West	Transpantaneira Road, Poconé, Mato Grosso	LMSM 2673; LMSM 429-430 (Donation from CMIOC).	Donation	10	16º 22'30”S, 56º 40'12”W
O. unguis	Central West	Cáceres, Mato Grosso	LMSM 3334	Survey	10	16º 31'26.4”S, 57º 50'16.8”W
O. unguis	Central West	Várzea Grande, Mato Grosso	LMSM 3344	Survey	10	15º 33'23.4”S, 56º 16'53.04”W
Omalonyx sp.	Central West	Barão de Melgaço, Mato Grosso	LMSM 433 (Donation from CMIOC).	Donation	10	16º 49'14.52”S, 56º 19'19.2”W
			CMIOC 9565	Museum
Omalonyx sp.	Central West	Barão de Melgaço, Mato Grosso	CMIOC 9565	Museum	10	16º 49'14.52”S, 56º 19'19.2”W
Omalonyx sp.	Central West	Manso Lake, Mato Grosso	LMSM 784-86, 791 (Donation from CMIOC)	Donation	10	15º 26'20.4”S, 55º 11'9.96”W
Omalonyx sp.	Central West	Chapada dos Guimarães, Mato Grosso	LMSM 3032 (Donation from CMIOC)	Donation	10	15º 6'30.24”S, 55º 32'22.92”W
Omalonyx sp.	Central West	Nobres, Mato Grosso	LMSM 3028, 3030 (Donation from CMIOC)	Donation	10	14º 21'51.12”S, 55º 46'48”W
Omalonyx sp.	Central West	Santo Antônio do Leverger, Mato Grosso	LMSM 3029 (Donation from CMIOC)	Donation	10	16º 27'23.4”S, 55º 26'22.92”W
O. matheroni	Central West	Barra do Garças, Mato Grosso	MCP 09189	Museum	10	15º 21'34.56”S, 52º 29'50.28”W
O.matheroni	South	Paranaguá, Paraná	MZSP 18440 (Arruda et al. 2009)	Literature	12	25º 32'39.48”S, 48º 32'47.4”W
Omalonyx sp.	South	Paranaguá, Paraná	MZSP 18440 (Arruda et al. 2009)	Literature	12	25º 32'39.48”S, 48º 32'47.4”W
Omalonyx sp.	South	Sete Quedas, Guaíra, Paraná	MZSP 31884	Museum	12	24º 48'25.2”S, 54º 15'12.24”W
O. convexus	South	Curitiba, Paraná	LMSM 2667, 2975, 2990-91, 3003, 3008, 3011	Survey	12	25º 28'41.16”S, 49º 17'17.16”W
O. unguis	South	Foz do Iguaçu, Paraná	LMSM 3260	Survey	12	25º 28'15.24”S, 54º 28'56.28”W
O. unguis	South	Foz do Iguaçu, Paraná	MNRJ 32146, 32205	Museum	12	25º 28'15.24”S, 54º 28'56.28”W
O. unguis	South	Foz do Iguaçu, Paraná	MNRJ 32146, 32205	Museum	12	25º 28'15.24”S, 54º 28'56.28”W
O. convexus	South	Araranguá, Santa Catarina	LMSM 1522, 2988-89, 3001-02, 3005-07	Survey	12	28º 56'33.36”S, 49º 28'22.08”W
O. matheroni	South	Near to Tironi Park, Piçarras, Santa Catarina	LMSM 3942, 4024-4028	Survey	12	26º 45'56.88”S, 48º 42'38.88”W
O. convexus	South	São João do Sul, Santa Catarina	MCP 09271 (Agudo-Padron 2008)	Literature	12	29º 12'22.32”S, 49º 48'46.08”W
O. convexus	South	Camboriú, Santa Catarina	Agudo-Padron 2008	Literature	12	27º 42'43.2”S, 48º 42'32.4”W
O. convexus	South	Paulo Lopez, Santa Catarina	Agudo-Padron 2008	Literature	12	27º 57'53.28”S, 48º 45'39.6”W
O. convexus	South	Criciúma, Santa Catarina	Agudo-Padron 2008	Literature	12	28º 42'59.04”S, 49º 22'49.8”W
O. matheroni	South	Biguaçu River, Biguaçu, Santa Catarina	LMSM 3507, 3508	Survey	12	27º 28'27.84”S, 48º 40'9.84”W
O. convexus	South	Florianópolis, Santa Catarina	MCP 09190-1	Museum	12	27º 24'24.12”S, 48º 25'45.84”W
O. convexus	South	Palhoça, Santa Catarina	MCP 09227	Museum	12	27º 46'44.76”S, 48º 40'15.6”W
O. convexus	South	Porto Alegre, Rio Grande do Sul	Martens 1868, Heynemann 1868; Lange de Morretes 1949; Tillier 1981, Simone 2006; MCNZ: 8058, 1524, 31590, 4439, 5501, 35546 (Arruda & Thomé 2011)	Literature	12	31º 14'58.56”S, 51º 30'37.08”W
O. convexus	South	Porto Alegre, Rio Grande do Sul	MCP 02066, 08834, 08837-8, 08849, 08842-3, 08845, 09273-4	Museum	12	31º 14'58.56”S, 51º 30'37.08”W
O. convexus	South	Camaquã, Rio Grande do Sul	Parodiz 1963; MCP 8841 (Arruda & Thomé 2011)	Literature	12	30º 55'21.36”S, 51º 47'18.6”W
Omalonyx sp.	South	Camaquã, Rio Grande do Sul	MCP 09272; MZSP 7539	Museum	12	30º 55'21.36”S, 51º 47'18.6”W
O. unguis	South	São Leopoldo, Rio Grande do Sul	MCP 10247, 10240-1, 10291; MZSP 31961,18439	Museum	12	29º 45'19.08”S, 51º 8'42.72”W
Omalonyx sp.	South	São Leopoldo, Rio Grande do Sul	MCP 10247, 10240-1, 10291; MZSP 31961,18439	Museum	12	29º 45'19.08”S, 51º 8'42.72”W
Omalonyx sp.	South	Pelotas, Rio Grande do Sul	MZSP 31964	Museum	12	31º 34'7.68”S, 52º 21'38.16”W
O. convexus	South	Rio Grande, Rio Grande do Sul	MCP 08836 (Arruda & Thomé 2011)	Literature	12	32º 13'10.92”S, 52º 24'15.48”W
O. convexus	South	Viamão, Rio Grande do Sul	LMSM 2650-51, 2666, 2668-69, 2704, 2759, 2762-63, 2768, 2895-97	Survey	12	30º 10'12”S, 50º 52'10.56”W
O. convexus	South	Viamão, Rio Grande do Sul	MCNZ 2506 (Arruda & Thomé, 2011)	Literature	12	30º 10'12”S, 50º 52'10.56”W
O. convexus	South	Arambaré, Rio Grande do Sul	LMSM 3009-10, 3021-23, 3149-50, 3167, 3175, 3187	Survey	12	30º 55'9.12”S, 51º 34'42.6”W
O. convexus	South	Cachoeira do Sul, Rio Grande do Sul	MCP 08840 (Arruda & Thomé 2011)	Literature	12	30º 12'22.32”S, 52º 59'11.04”W
O. convexus	South	Santa Maria, Rio Grande do Sul	MCP 08829-31 (Arruda & Thomé 2011)	Literature	12	29º 47'56.4”S, 53º 49'29.28”W
O. convexus	South	Novo Hamburgo, Rio Grande do Sul	MCP 08848 (Arruda & Thomé 2011)	Literature	12	29º 44'6.72”S, 51º 29'13.2”W
O. convexus	South	Mampituba Stream, Torres, Rio Grande do Sul	MCP 08832 (Arruda & Thomé 2011);	Literature	12	29º 35'29.76”S, 49º 57'36”W
O. convexus	South	Mampituba Stream, Torres, Rio Grande do Sul	LMSM 3932-3941	Survey		29º 35'29.76”S, 49º 57'36”W
O. convexus	South	Cachoeirinha, Rio Grande do Sul	MCP 09548 (Agudo Padron 2012); MCP 08839 (Arruda & Thomé 2011)	Literature	12	29º 55'15.96”S, 51º 56'56.4”W
O. convexus	South	Vacaria, Rio Grande do Sul	MCNZ 7559 (Arruda & Thomé 2011)	Literature	12	28º 22'14.88”S, 50º 55'24.96”W
O. convexus	South	Sapiranga, Rio Grande do Sul	MCNZ 2877 (Arruda & Thomé 2011)	Literature	12	29º 36'50.4”S, 50º 59'43.8”W
O. convexus	South	Guaíba, Rio Grande do Sul	MCNZ 6000 (Arruda & Thomé 2011)	Literature	12	30º 10'39.36”S, 51º 26'9.6”W
O. convexus	South	Triunfo, Rio Grande do Sul	MCNZ 8058 (Arruda & Thomé 2011)	Literature	12	29º 50'37.32”S, 51º 34'17.04”W
			MCP 06487	Museum
O. convexus	South	Triunfo, Rio Grande do Sul	MCP 06487	Museum	12	29º 50'37.32”S, 51º 34'17.04”W
O. unguis	South	Imbé, Rio Grande do Sul	MCNZ 31969 (Arruda & Thomé 2011)	Literature	12	29º 55'50.16”S, 50º 7'55.2”W
O. convexus	South	Capão do Corvo, Canoas, Rio Grande do Sul	MCNZ 597 (Arruda & Thomé 2011)	Literature	12	29º 54'48.24”S, 51º 10'37.2”W
O. convexus	South	Taquara, Rio Grande do Sul	MCNZ 2610 (Arruda & Thomé 2011)	Literature	12	29º 40'15.6”S, 50º 45'47.52”W
O. convexus	South	Portão, Rio Grande do Sul	MCNZ 3264 (Arruda & Thomé 2011)	Literature	12	29º 42'36”S, 51º 14'56.76”W
O. convexus	South	Estrela, Rio Grande do Sul	MCP 08844 (Arruda & Thomé 2011)	Literature	12	29º 30'33.48”S, 51º 55'11.64”W
O. convexus	South	Eldorado do Sul, Rio Grande do Sul	MCP 08835	Museum	12	30º 46'58.8”S, 51º 29'54.24”W
Omalonyx sp.	South	São Borja, Rio Grande do Sul	MCP 09270; MCP 08828; MCP 08835	Museum	10	28º 44'46.68”S, 55º 47'50.28”W
O. convexus	South	Mampituba, Rio Grande do Sul	MCP 08833	Museum	12	29º 15'43.92”S, 50º 13'12”W
O. brasiliensis	South	Rio Grande do Sul	ZMB 45.913 (Arruda & Thomé 2008a).	Literature	10/dez	29º 36'18.24”S 53º 12'10.25”W unespecified locality
O. brasiliensis	South	Rio Grande do Sul	MNRJ 57927, 57955	Museum	10/dez	29º 36'18.24”S 53º 12'10.25”W unespecified locality

• Note: 1: Specimens from our malacological surveys in Brazil were deposited in LMSM and classified in the column source as “Survey”; Specimens that were donated by other researchers were deposited in LMSM and classified in the column source as “Donation”; 2: Hydrographic region numbers are according to Figure 1 and to the metadata information system of the water resources national agency - ANA - of the Environment Ministry, Brazil and to Bonetto 1994).

Table 3
Records of Omalonyx in South America and Lesser Antilles based on literature data, institutional collections and our own malacological surveys.

Species	Country	Locality	1Record	2Source	3Hydrographic Region	Coordinates
O. unguis	Argentina	Rio Santiago, Buenos Aires	MACN 10218-1 (Hylton-Scott 1968); MACN 10208; 10268; MLP 31321 (Arruda & Thomé 2008b), Coscarelli & Vidigal 2011	Literature	10	34º 55'15.96”S, 57º 57'15.84”W
Omalonyx sp.	Argentina	Punta Lara, Buenos Aires	MZSP 31866	Museum	10	34º 49'40.8”S, 57º 57'56.52”W
O. convexus	Argentina	Ezeiza, Buenos Aires	Camaggni coll. 1971 (Tillier 1981); MNHN unnumbered (Arruda & Thomé 2008b)	Literature	10	34º 51'13.68”S, 58º 31'22.44”W
O. convexus	Argentina	La Plata, Buenos Aires	LMSM 3273, 3237	Survey	10	34º 55'15.96”S, 57º 57'15.84”W
O. convexus	Argentina	Rio Santiago, Buenos Aires	MNHN, unnumbered; MACN 14472 (Arruda & Thomé 2008b)	Literature	10	34º 55'15.96”S, 57º 57'15.84”W
O. convexus	Argentina	Tucumán, Tucumán	Hylton-Scott 1968, 1971; SMNH 2507 (Tillier 1981); MNHN unnumbered (Arruda & Thomé 2008b)	Literature	11	26º 48'30.24”S, 65º 13'33.6”W
O. unguis	Argentina	Tucumán, Tucumán	MNRJ 4470	Museum	11	26º 48'30.24”S, 65º 13'33.6”W
O. convexus	Argentina	Rosario, Santa Fe	CM and MZUM unnumbered (Parodiz, 1963); MACN 26577 (Hylton-Scott & Lapuente 1968); USNM 124546 (Tillier 1981); ZMB28513 (Arruda & Thomé 2008b)	Literature	10	32º 56'40.2”S, 60º 39'10.8”W
O. convexus	Argentina	Rosario, Santa Fe	ANSP 64116	Museum	10	32º56'40.2”S, 60º 39'10.8”W
O. convexus	Argentina	Rio Negro, Chaco	CM unnumbered (Parodiz 1963), (Arruda & Thomé 2008b)	Literature	10	27º 29'39.12”S, 58º 44'38.4”W
O. convexus	Argentina	Islands in Paraná River, near Santa Fe	CM unnumbered (Parodiz 1963), (Arruda & Thomé 2008b)	Literature	10	31º 56'57.84”S, 60º 27'28.44”W
Omalonyx sp.	Argentina	Lagunas Pampeanas, Buenos Aires	Tietze & Francesco 2012	Literature	10	_
O. unguis	Argentina	Locality between Santa Fe and Paraná, both in Argentina	Zilli et al. 2008	Literature	10	_
O. unguis	Argentina	Site within Chaco Province, on the west bank of the Paraná River at its confluence with Paraguay River	Franceschini et al. 2010	Literature	10	_
O. convexus	Argentina	Abra Vieja, Paraná River, Buenos Aires	CM and MACN unnumbered (Parodiz 1963), (Arruda & Thomé 2008b)	Literature	10	34º 34'43.32”S, 58º 48'15.12”W
O. convexus	Argentina	Perucho Verna Stream, Entre Rios	UF 159845 (Arruda & Thomé 2008b)	Literature	10	23º 34'25.32”S, 64º 8'31.2”W
O. convexus	Argentina	Vinalito, Jujuy	CM unnumbered (Parodiz 1963), (Arruda & Thomé 2008b)	Literature	10	23º 34'25.32”S, 64º 8'31.2”W
O. convexus	Argentina	Santa Bárbara Ridge, Jujuy	CM unnumbered (Parodiz 1963), (Arruda & Thomé 2008b)	Literature	10	23º 46'33.6”S, 64º 40'10.56”W
O. convexus	Argentina	Termas del Palmar, Salta	CM unnumbered (Parodiz 1963); MACN 27246 (Arruda & Thomé 2008b)	Literature	10	24º 14'54.96”S, 63º 27'12.96”W
O. convexus	Argentina	Orán, Salta	CM unnumbered (Parodiz 1963), (Arruda & Thomé 2008b)	Literature	10	23º 8'9.96”S, 64º 19'19.92”W
O. unguis	Argentina	Resistencia, Chaco	MACN22931 (Arruda & Thomé 2008b)	Literature	10	27º 29'39.12”S, 58º 44'38.4”W
O. unguis	Argentina	Resistencia, Chaco	MZSP 14748	Museum	10	27º 29'39.12”S, 58º 44'38.4”W
O. convexus	Argentina	Guaycurú Stream, Chaco	CM unnumbered (Parodiz 1963), (Arruda & Thomé 2008b)	Literature	10	26º 21'50.4”S, 60º 51'16.2”W
O. convexus	Argentina	Navarro, Buenos Aires	MACN 27241 (Hylton-Scott & Lapuente 1968)	Literature	10	34º 59'57.84”S, 59º 16'42.96”W
O. convexus	Argentina	Las Rosas, Buenos Aires	MACN 14860 (Hylton-Scott & Lapuente 1968), (Arruda & Thomé 2008b)	Literature	10	36º 26'56.4”S, 58º 50'27.96”W
O. convexus	Argentina	Chapadmalal, Buenos Aires	Hylton-Scott & Lapuente 1968; MACN 27242 (Arruda & Thomé 2008b)	Literature	11	38º 54'43.2”S, 58º 14'46.68”W
O. unguis	Argentina	Barca Grande, Buenos Aires	MACN 13996 (Hylton-Scott & Lapuente 1968, Arruda & Thomé 2008b); Coscarelli & Vidigal 2011	Literature	10	34º 14'54.24”S, 58º 44'45.6”W
O. unguis	Argentina	Guaycolec, Formosa	Hylton-Scott & Lapuente 1968, Coscarelli & Vidigal 2011	Literature	10	26º 11'49.2”S, 58º 10'32.88”W
O. unguis	Argentina	Formosa, Formosa	MLP 4567-1 (Arruda & Thomé 2008b), Coscarelli & Vidigal 2011	Literature	10	26º 11'49.2”S, 58º 10'32.88”W
O. unguis	Argentina	Manantiales, Corrientes	Hylton-Scott & Lapuente 1968, Coscarelli & Vidigal 2011	Literature	10	27º 55'19.2”S, 58º 59'42”W
O. unguis	Argentina	Oro River, Chaco	MACN unnumbered (Hylton-Scott & Lapuente 1968), Coscarelli & Vidigal 2011	Literature	10	26º 47'16.08”S, 59º 26'42”W
O. unguis	Argentina	Tragadero River, Locality between Barraqueras and Antequera, Chaco	Poi de Neiff et al. 1977	Literature	10	27º 29'39.12”S, 58º 44'38.4”W
O. unguis	Argentina	Catamarca, Catamarca	Cazzaniga 1985	Literature	11	28º 28'21”S, 65º 46'45.48”W
Omalonyx sp.	Argentina	Ensenada, Buenos Aires	MLP 31321	Museum	10	34º 51'53.28”S, 57º 54'30.6”W
Omalonyx sp.	Argentina	Atalaya, Buenos Aires	LMSM 23	Donation	10	35º 14'56.4”S, 57º 31'53.76”W
Omalonyx sp.	Argentina	Esteros de Iberá, Corrientes	LMSM 16-22, 234-35	Donation	10	28º 20'24”S, 57º 22'56.64”W
O. convexus	Argentina	Ciudad Autónoma de Buenos Aires, Buenos Aires	LMSM 3239-40; ANSP 23465	Survey	10	34º 35'58.92”S, 58º 22'54.84”W
O. unguis	Argentina	Villafañe, Formosa	MLP 11878 (Arruda & Thomé 2008b)	Literature	10	26º 14'10.32”S, 59º 7'48”W
O. unguis	Argentina	Bahía Blanca, Buenos Aires	Cazzaniga 1985	Literature	11	38º 43'58.8”S, 62º 15'58.68”W
Omalonyx sp.	Argentina	Misiones	MLP unnumbered (Gregoric et al. 2013)	Literature	10	27º 27'36”S, 54º 35'29.4”W
O. unguis	Argentina	Formosa	MLP 4567-1 (Arruda & Thomé 2008b)	Literature	10	24º 52'12”S, 60º 26'27.6”W
O. unguis	Argentina	Tigre, Buenos Aires	LMSM 734 (Arruda & Thomé 2008b)	Literature	10	34º 25'36.48”S, 58º 34'46.2”W
O. unguis	Argentina	Buenos Aires, Buenos Aires	ANSP 23465	Museum	10	34º 35'58.92”S, 58º 22'54.84”W
Omalonyx sp.*	Chile	Juan Fernandes	Odhner, 1922, Letelier et al. 2014	Literature	13	33º 46'23.52”S, 80º 46'33.6”W
Omalonyx sp.*	Chile	Valparaiso Region	ANSP 64117	Museum	13	32º 39'6.48”S, 71º 24'21.6”W
Omalonyx sp.*	Chile	Valparaiso Region Robinson Crusoe Island, Juan Fernandez Archipelago	ANSP 130450, A9768G	Museum	13	34º 10'12”S, 80º 49'59.88”W
Omalonyx sp.	Colombia	_	FMNH unnumbered (Vera-Ardila 2008)	Literature	5	0º 14'8.88”S, 72º 30'0”W
O. matheroni	Ecuador	Limoncocha Lake	Hermann & Dundee 1967; FMNH 157321(Tillier 1981)	Literature	5	0º 23'57.12”S, 76º 36'33.12”W
O. geayi	Ecuador	Limonconcha, Sucumbios	FMNH 328261 (Arruda et. al 2016)	Literature	5	0º 24'41.91”S, 76º 37'31.36”W
O. matheroni	French Guiana	Kourou Bridge	Tillier coll. 4.78 (Tillier 1981); MNHN (Arruda & Thomé 2008a)	Literature	4	5º 9'39.24”N, 52º 38'57.48”W
O. geayi	French Guiana	Route Cayene-Kourou, Kaw Swamps	MNHN, Tillier coll. 29.4.1977 (Tillier 1980); MNH. (Tillier 1981), (Arruda et al. 2016)	Literature	4	4º 30'52.92”N, 52º 39'57.6”W
O. geayi	French Guiana	Kaw Swamps	LMSM 3204, 3222-24, 3226	Survey	4	4º 30'52.92”N, 52º 39'57.6”W
O. matheroni	Guyana	Demerara	Gibbson 1879; BMNH 1930.5.14.6.11 (Tillier 1981)	Literature	4	6º 37'53.04”N, 58º 38'27.6”W
O. matheroni	Guyana	Manikol Swamps (upper Tuyuni)	BMNH 1936.12.2.27.29 (Tillier 1981)	Literature	4	5º 57'18”N, 57º 41'26.16”W
Omalonyx sp.	Guyana	Georgetown	CMIOC 455	Museum	4	6º 47'52.8”N, 58º 9'19.08”W
O. matheroni	Lesser Antilles, Trinidad and Tobago,	Port Spain	ANSP A1173	Museum	_	10º 39'44.28”N, 61º 31'48”W
O. matheroni	Lesser Antilles, Guadeloupe	Pointe- à - Pitre	MNHN (Arruda & Thomé, 2008a)	Literature	_	16º 13'59.88”S, 61º 31'59.88”W
O. matheroni	Lesser Antilles, Guadeloupe	Pico Spring	LMSM 379-85, 2186-95 donated by Dr. J. P. Poitier collection	Donation	_	16º 13'59.88”S, 61º 31'59.88”W
O. matheroni	Lesser Antilles, Guadeloupe	Céligny and other localities	Lesson 1838, Tillier 1981 (Dr. J. P. Poitier collection)	Literature	_	16º 13'59.88”S, 61º 31'59.88”W
O. matheroni	Lesser Antilles, Guadeloupe	Vallet Pond	ANSP A22070	Museum	_	16º 13'59.88”S, 61º 31'59.88”W
O. matheroni	Lesser Antilles, Santa Lucia	-	Hermann & Dundee 1967	Literature	_	13º 54'7.2”N, 60º 58'42.96”W
O. pattersonae	Lesser Antilles, Antigua		Hermann & Dundee 1967; MZUM, (Patterson 1971); USNM 272284, 215047; BMNH 95.1.29.17 (Tillier 1981)	Literature	_	17º 42'14.4”N, 61º 48'25.2”W
O. unguis	Lesser Antilles, Antigua and Barbuda		ANSP 71975	Museum	_	17º 42'14.4”N, 61º 48'25.2”W
O. matheroni	Lesser Antilles, Trinidad and Tobago		USNM 162058	Museum	_	10º 26'44.52”N, 61º 16'17.04”W
O. matheroni	Lesser Antilles, Trinidad		BMNH 1950.618.407; LMNH (Tillier 1980, 1981)	Literature	_	10º 26'44.52”N, 61º 16'17.04”W
O. matheroni	Lesser Antilles, Trinidad and Tobago	Tunapuna-Piarco, Saint George East	USDA 100453 (Arruda et al. 2016)	Literature		10º 37'29.7336”N, 61º 13'6.5316”W
O. matheroni	Lesser Antilles, Monserrat	St. Peter	ANSP A23921	Museum	_	16º 44'18.24”N, 62º 12'31.68”W
Omalonyx sp.	Lesser Antilles, Antigua and Barbuda	-	USNM 460663, 151347	Museum	_	17º 42'14.4”N, 61º 48'25.2”W
O. unguis	Paraguay	Paraná River near Corrientes and Moxos (Bolivia)	d’Orbigny 1835, 1837; Tillier (1981)	Literature	10	27º 57'57.6”S, 58º 14'35.52”W
O. unguis	Paraguay	Asunción	CM unnumber (Parodiz 1963); MACN 19968 (Arruda & Thomé 2008b)	Literature	10	25º 16'32.88”S, 57º 38'16.08”W
O. unguis	Paraguay	Asunción	LMSM 3436	Survey	10	25º 16'32.88”S, 57º 38'16.08”W
O. unguis	Paraguay	Pilar, Ñe	LMSM 3341	Survey	10	26º 51'11.88”S, 58º 17'44.88”W
O. convexus	Paraguay	San Bernardino	CM unumber (Parodiz 1963)	Literature	10	25º 16'46.92”S, 57º 17'7.08”W
O. unguis	Paraguay	Villa Rica	MCZ unumber (Parodiz 1963), (Arruda & Thomé 2008b)	Literature	10	25º 49'26.4”S, 56º 24'18”W
O. unguis	Paraguay	Puerto Guaraní	MACN 18181 (Hylton-Scott & Lapuente 1968), Coscarelli & Vidigal 2011	Literature	10	21º 17'20.4”S, 57º 55'26.4”W
Omalonyx sp.	Paraguay	Riacho Nepengue, Concepción	INPA 485	Museum	10	22º 27'23.76”S, 57º 35'19.68”W
O. unguis	Paraguay	Paso de Patria, Ñe	LMSM 3434, 3350	Survey	10	27º 14'52.08”S, 58º 32'20.04”W
Omalonyx sp.	Peru	Tarapoto, San Martín Morales, San Martín	MZSP 43266; USMN 612118 (Tillier 1981)	Literature	5	6º 11'6.36”S, 76º 28'44.4”W
O. matheroni	Peru	San Martín	MCP 08850	Museum	5	6º 25'30.72”S, 76º 49'51.24”W
O. unguis	Peru	Lake Yarinacocha, Ucayali	Ramirez, 1991, Ramirez et al. 2003	Literature	5	8º 18'29.88”S, 74º 36'7.2”W
O. matheroni	Suriname	Zanderij	RMNH 15.6.67 (Tillier, 1981)	Literature	4	5º 27'21.24”N, 55º 12'39.6”W
O. matheroni	Suriname	Belwaarde	RMNH 2.9.69 (Tillier 1981)	Literature	4	5º 51'6.12”N, 55º 52'55.2”W
O. matheroni	Suriname	Paramaribo	RMNH 6.68 (Tillier 1981)	Literature	4	5º 51'7.2”N, 55º 12'13.32”W
O. geayi	Suriname	Paramaribo	FLMNH 463461 (Arruda et al. 2016)	Literature	4	5º 51'7.2”N, 55º 12'13.32”W
O. matheroni	Suriname	Brokobakka, Brokopondo	RMNH unnumbered (Tillier 1981)	Literature	4	3º 53'22.56”N, 55º 34'28.56”W
O. unguis	Uruguay	Fuente Salto, close to Salto city	Olazarri 1979	Literature	10	31º 23'31.2”S, 57º 49'55.2”W
Omalonyx sp.	Uruguay	Montevideo	MZSP 31873	Museum	10	34º 54'43.2”S, 56º 9'52.2”W
O. convexus	Uruguay	Montevideo	ANSP 70261	Museum	10	34º 54'43.2”S, 56º 9'52.2”W
O. unguis	Uruguay	Near from Carrasco Stream, Montevideo	Scarabino 2003	Literature	10	34º 54'43.2”S, 56º 9'52.2”W
O. convexus	Uruguay	Miguelete Stream, Prado, Montevideo	Scarabino 2003	Literature	10	34º 54'43.2”S, 56º 9'52.2”W
O. convexus	Uruguay	Canelones	MNHNM8691 (Arruda & Thomé 2008b)	Literature	10	34º 43'29.28”S, 55º 57'34.56”W
O. unguis	Uruguay	Colonia, Uruguai River in front of Punta Gorda	MNHNM 3368 (Arruda & Thomé 2008b)	Literature	10	33º 57'7.56”S, 58º 21'36”W
O. matheroni	Venezuela	Caracas	Martens 1873, Tillier 1981, Arruda et al. 2009	Literature	2	10º 28'43.68”N, 66º 54'12.24”W
O. matheroni	Venezuela	Laguna de Ramón Coronel, near Bejuma	Baker 1925, 1926; Martinez 1993	Literature	3	9º 50'47.4”N, 68º 12'52.92”W
O. pattersonae	Venezuela	Lake Valencia, Carabobo	Martinez 1993	Literature	2	10º 9'13.32”N, 67º 53'40.92”W
O. pattersonae	Venezuela	Zuata Dam, Aragua	Martinez 1993	Literature	2	10º 11'39.84”N, 67º 23'40.56”W
O. matheroni	Venezuela	Santa Elena de Uiarém, Bolívar	LMSM 2271-75, 2336-372353-54, 2356-57, 2372-73, 2377, 2378-79, 2522-24	Survey	5	4º 35'43.08”N, 61º 6'10.08”W
O. pattersonae	Venezuela	Lake Tacarigua	ANSP 161142	Museum	2	10º 48'10.8”N, 65º 48'21.24”W
O. pattersonae	Venezuela	-	ANSP 140961	Museum	-	unespecified locality
Omalonyx sp.	Venezuela	Amacuro Delta	MCP 09193	Museum	2	9º 29'31.2”N, 62º 31'22.8”W
O. unguis	Bolivia	Santa Cruz de la Sierra	MZUM unnumbered (Parodiz 1963)	Literature/	5	17º 7'59.88”S, 63º 55'12”W
O. pattersonae	Bolivia	Santa Cruz de la Sierra	MCP 09185	Museum	5	17º 7'59.88”S, 63º 55'12”W
O. geayi	Bolivia	Santa Cruz	MNKMO 7 (Arruda et al. 2016	Literature	10	19º 7'45.0912”S, 61º 41'57.804”W
Omalonyx sp.	Bolivia	-	ANSP A1826c	Museum	5	17º 7'59.88”S, 63º 55'12”W
O. unguis	Lesser Antilles, Guadeloupe		ANSP 23463	Museum	_	16º 15'47.52”N, 61º 33'10.8”W
O. matheroni	Lesser Antilles, Montserrat	Daly River, Saint Peter	ANSP A23919	Museum	_	16º 44'18.24”N, 62º 12'31.68”W
O. matheroni	Lesser Antilles, Montserrat		ANSP 144327	Museum	_	16º 44'13.92”N, 62º 11'33.36”W
O. matheroni	Lesser Antilles, Monserrat	Runaway Ghaut, Saint Peter	ANSP A23917-18, A23920, 466625, A23921	Museum	_	16º 45'27”N, 62º 13'12”W
O. matheroni	Lesser Antilles, Montserrat	Woollands, Saint Peter	ANSP A23921	Museum	_	16º 44'18.24”N, 62º 12'31.68”W

• Note: 1: Museum abbreviation is according to Table 1; 2: Specimens from our malacological surveys were deposited in LMSM and they were classified in the column source as “Survey”; Specimens that were donated by other researchers were deposited in LMSM and they were classified in the column source as “Donation”. 3: Hydrographic basin numbers are according to Figure 1 and to the metadata information system of the water resources national agency - ANA - of the Environment Ministry, Brazil and to Bonetto 1994); * Specimens from Chile that were previously identified as O. gayana, however, Tillier 1981 considered that this species belongs to the genus Succinea.

To investigate in detail the distribution of these slugs in Brazil, malacological surveys comprising all geographical regions (North, Northeast, Southeast, South and Central West) were conducted between 2006 and 2016 (permission from environmental agency: ICMBio/SISBIO no. 12113-3). Specimens were manually collected from wet soil and vegetation in the vicinity of freshwater systems. Voucher specimens were deposited in the malacological collection of the Laboratório de Malacologia e Sistemática Molecular (LMSM), at Universidade Federal de Minas Gerais, Minas Gerais, Brazil.

All localities from the literature review, museums, collections, donations and our own malacological surveys were listed (Table 2 and 3) and plotted on a map (Figure 1) using the software ArcGIS 10.4 (ArcGIS Desktop 10.4 Geostatistical Analyst, Environmental Systems Research Institute ESRI, 2016). The geographic position of the localities and the information about South American hydrography and geography were cross-checked with Google Earth, Global Gazetteer, Hydro web (a hydrologic information system of Agência Nacional de Águas - ANA, the national water resources agency of the Environment Ministry, Brazil). Information regarding the hydrography of Austral South America was obtained from Bonetto (1994).

Figure 1
Updated distribution of the genus Omalonyx across Neotropical region. The coloured areas represent different hydrographic regions and their respective numbers. The solid black line indicates the borders among South American countries and within Brazilian administrative regions. The species records were represented by colours dots: red = O. matheroni; blue = O. convexus; green = O. unguis; yellow = O. geayi, purple = O. pattersonae, black = O. brasiliensis; gray = do not identified until species level, or Omalonyx sp. and gray circle with black border = Specimens from Chile that were previously identified as O. gayana. The stars represents the records made in our surveys, the circles represents literature or museums data and the cross symbol represents the samples that were donated by other researchers. Details about each sample are on tables 2 and 3. Hydrographic regions are indicated by numbers: 1) Pacific Coast; 2) Caribbean sea; 3) Orinoco River; 4) Amapá-Esequibo; 5) Amazon River; 6) Tocantins River; 7) North Atlantic; 8) São Francisco River; 9) Eastern Atlantic; 10) Del Plata; 11) Border strip of the Brasilica (North) and the Chilean‑Patagonian (South West) Subregion; 12) Eastern; 13) Chilean-Patagonian Subregion of the Pacific Versant; 14) Chilean-Patagonian Subregion of the Atlantic Versant.

Morphological identification of specimens collected in our malacological surveys was based on characteristics of the reproductive system according to the following literature: O. convexus (Hylton-Scott & Lapuente 1968, Hylton-Scott 1971, Tillier 1981, Arruda & Thomé 2008b), O. unguis (Coscarelli & Vidigal 2011), O. matheroni, O. pattersonae and O. geayi (Tillier 1981). Specific identification provided in the papers (literature review) and on the labels (museum specimens) was also used in this work. Some of these records were not identified to species level and are designated Omalonyx sp. Until 1981, there were several species of Omalonyx, now recognized as synonyms. Throughout the text, species are designated according to Tillier (1981) and Arruda & Thomé (2008a, b), where synonyms for the six valid Omalonyx species can be found. However, when consulting the topic references, the reader will find the former designation.

Data of occurrence (Table 2 and 3) were used to model the species geographic distributions using one topographic variable (altitude) and the nineteen bioclimatic variables derived from the WorldClim database v. 1.4 as showed by Vogler et al. (2013) (Table 4). The classifications of climate were based on Koppen-Geiger climate classification types for South America (Peel et al. 2007). Maps for the distribution of O. matheroni, O. pattersonae, O. geayi, O. convexus and O. unguis were produced.

Table 4
Bioclimatic variables used in models development.

Variable	Description
Alt	Altitude
bio1	Annual mean temperature
bio2	Mean diurnal range (monthly mean, T° max-T° min)
bio3	Isothermality (bio2/bio7) x 100
bio4	Temperature seasonality (standard deviation x 100)
bio5	Maximum temperature of warmest month
bio6	Minimum temperature of coldest month
bio7	Temperature annual range (bio5-bio6)
bio8	Mean temperature of wettest quarter
bio9	Mean temperature of driest quarter
bio10	Mean temperature of the warmest quarter
bio11	Mean temperature of coldest quarter
bio12	Annual precipitation
bio13	Precipitation of wettest month
bio14	Precipitation of driest month
bio15	Precipitation seasonality (coefficient of variation)
bio16	Precipitation of wettest quarter
bio17	Precipitation of driest quarter
bio18	Precipitation of the warmest quarter
bio19	Precipitation of the coldest quarter

To minimize the spatial autocorrelation of the bioclimatic variables and to determine which variables contributed more to the development of the model, a principal component analysis (PCA) was carried out in the areas of Omalonyx species occurrence. The resulting rasters were used to generate a potential distribution model for South America. The input parameters followed the MaxEnt (version 3.3.3k) (Phillips et al. 2004) default options except for the threshold rule, which was set as “minimum training presence”. The resulting models were processed and reclassified using ArcGIS. A binary map (absence-presence) for the potential distribution of a species was generated considering the average map that represents the induced and adjusted habitat of each species.

Results

1. Literature review

Inferences on the distribution of Omalonyx species have been made since its description, and it was assumed to be throughout South America east of the Andes (d’Orbigny 1837). This first inference was based on records from Bolivia and Paraguay (d’Orbigny 1835a, 1837). However, at that time (1837), the name Omalonyx was used as the subgenus Succinea (Omalonyx) unguis. Later, Omalonyx was used at the genus level (Herrmannsen 1849). In addition to the publications of d’Orbigny other species were described at that time as showed below. In the next century, Patterson (1971) extended the distribution of the genus to several West Indies islands and Central America. However, the basis for this conclusion was not clearly demonstrated. After that, Tillier (1981) demonstrated the occurrence of Omalonyx species in all South America east of the Andes and the Lesser Antilles. His conclusion was based on preserved specimens from malacological collections that did not include significant sampling material from Brazil, although there were already records on the presence of Omalonyx spp. in the country years before (e.g., Moricand 1836, Gibbons 1879). In fact, Tillier (1981) studied animals from only eight localities in Brazil, and four of these could not be clearly located and were excluded from his study. In this work, Tillier also discusses the origin and evolution of South American and Juan Fernandéz Islands (Chile) succineids. He suggests that the southeast region of Brazil is the center of Omalonyx radiation once three species can be found in this region (O. unguis, O. matheroni and O. brasiliensis). Details on the records of Omalonyx occurrence in the Neotropics are given below in the subsections “Omalonyx in Brazil” and “Omalonyx in other South American countries and Lesser Antilles”.

1.1. Literature review: Omalonyx in Brazil

The first record of Omalonyx in Brazil was made in the 19^th century in the Northeastern region (Moricand 1836) on a lake in Bahia State named “la Digue” or “le Baril”. The specimens were identified as O. unguis. Hidalgo (1869) also identified as O. unguis specimens collected by Paz and Martinez in Bahia State. Two years later, the same author (Hidalgo 1872) stated that Paz and Martinez collected those specimens at “Lago Dique” (Dike Lake), Salvador, Bahia. We suppose that the specimens cited by Moricand (1836) and Hidalgo (1869, 1870) were collected in an urban lake known since the colonial period as “Dique do Tororó”. Gibbons (1879) identified two different species of Omalonyx in Bahia State, O. unguis and O. matheroni. However, no other information about the locality was provided, and the morphology described in Gibbons (1879) is not compatible with O. unguis; thus these records were not included in Table 2. Omalonyx convexus was described by Martens (1968) as Succinea convexa from specimens collected in Porto Alegre, Rio Grande do Sul State, in southern Brazil (type locality), and it was later included in the genus Omalonyx (Arruda & Thomé 2008b). The map provided by Arruda and Thomé (2008b) shows overlapping distribution of O. convexus and O. unguis in the Argentinean region of the Paraná River basin (in Figure 1 the Paraná River basin is included in the Del Plata hydrographic region) and adjacent localities in Uruguay. Omalonyx brasiliensis was described by Simroth (1896) based on specimens collected by H. von Ihering in Rio Grande do Sul State.

In the 20^th century, specimens of Omalonyx infected by Leucochloridium, an avian trematode, were found by Lutz (1921) in the surroundings of the institute where he used to work in Rio de Janeiro city, Rio de Janeiro State. The author also reported that this slug is abundant in the north of Brazil. This trematode was also found in birds from Mato Grosso and used in the experimental infection of Omalonyx (Travassos 1928). Both of these works have a parasitological focus, and the specific identification of the slug was not provided. Haas (1939) registered O. unguis for the State of Pernambuco but did not specify the locality. Parodiz (1957) recorded O. unguis in Brazil but did not include the locality. He also mentioned the occurrence of O. unguis in Porto Alegre (Rio Grande do Sul State) and observed its similarity to O. convexus. Based on specimens from the MCZ (lot number unavailable), Parodiz (1963) registered the occurrence of Omalonyx in Rio de Janeiro (O. unguis) and Camaquã, Rio Grande do Sul. The specimens from Camaquã were later identified as O. convexus (Arruda & Thomé 2008b). Lange de Morretes (1949) recorded O. brasiliensis and O. unguis in Vila Nova (Bahia State) and O. matheroni in Santarém (Pará State). In a taxonomical review using specimens from institutional collections, Tillier (1981) studied animals from eight localities in Brazil. Three of them were easily identified: Santarém and Alenquer in Pará State, and Rio de Janeiro in Rio de Janeiro State. The other four localities, due to insufficient labeling information, could not be precisely located. Two of them were only superficially specified: “Brazil” Pernambuco State and Praya (=Praia) Grande (Rio de Janeiro State). The other two localities could not be identified: Santa Amélia, Amazonas and “Makthlawara” (BMNH 1929.10.2.6.22). This author also mentioned the occurrence of Omalonyx in Porto Alegre, Rio Grande do Sul State, and cited Martens (1868) and Simroth (1896), who also recorded O. brasiliensis in this State (Tillier 1981). The distribution of Omalonyx in Brazil was revisited by two authors whose results were similar to those of Lange de Morretes (1949). First, Salgado & Coelho (2003) reported some species of the genus in a review about Brazilian land snails but did not cite any locality. After that, Simone (2006) cited the occurrence of O. brasiliensis in Rio Grande do Sul State and considered the occurrence area for the genus Omalonyx to be from Bolivia to Patagonia. Several other records were made in Brazil, including Minas Gerais (Oliveira & Almeida 2000, Arruda et al. 2006, Montresor et al. 2008) and São Paulo State (Arruda et al. 2009, Eduardo et al. 2012) in the southeast; Paraná (Arruda et al. 2009, Coscarelli & Vidigal 2011), Rio Grande do Sul (Arruda & Thomé 2008a, b, Arruda & Thomé 2011, Maltchik et al. 2010) and Santa Catarina State (Agudo-Padron 2008, 2012) in the south; Mato Grosso and Mato Grosso do Sul State (Coscarelli & Vidigal 2011) in the central west; Pernambuco (Dutra-Clarke et al. 2001), Sergipe (Jesus & Manso, 2010) and Maranhão State (Cantanhede et al. 2014) in the northeast; and Amazonas State in the North (Pimpão 2007, Garcia et al. 2012). Coscarelli & Vidigal (2011) investigated the distribution of O. unguis in Brazil and included new records for this species. Recently, new records for O. geayi extended the distribution range of this species in northern South America including Brazil (Arruda et al. 2016). The presence of Omalonyx was recorded in several Brazilian States representing all geographic regions (Table 2). All data and details (i.e., species and coordinates) on species distribution in Brazil were included in Table 2 and are shown in Figure 1.

1.2. Literature review: Omalonyx in other South American countries and Lesser Antilles

Several South American and Lesser Antilles countries are included in the distribution area of the genus Omalonyx (Figure 1, Table 3). The occurrence of O. unguis in Paraguay and Bolivia was reported by d’Orbigny (1835a, b, 1837). On this occasion, the author did a complete textual description of the external appearance of the animal and specified the collection sites: the flooded margins of Paraná River, near Corrientes, and the swamps of Moxos Province in Bolivia. Corrientes is a city on the riverbank of the Paraná River in Argentina, very close to the frontier with Paraguay, which is defined by the Paraná River itself. Later, Asunción, in Paraguay, was considered to be the type locality for O. unguis (Arruda & Thomé 2008b).

Omalonyx matheroni was described from individuals collected in Guadeloupe, Lesser Antilles (Potiez & Michaud 1835). Tillier (1981) studied specimens he collected or borrowed from institutional collections that were from several localities including the Lesser Antilles, Guiana, Suriname, French Guyana, Ecuador, Paraguay, Argentina and Peru (Table 3). Omalonyx occurrence in South American countries has been well documented by several authors: Argentina (Arruda & Thomé 2008a, b); Brazil (see above the topic geographic distribution of Omalonyx in Brazil); Colombia (Vera-Ardila 2008); Uruguay (Olazarri 1979, Scarabino 2003, Arruda & Thomé 2008b.); French Guiana (Tillier 1981, Arruda et al. 2016); Ecuador (Hermann & Dundee 1967, Tillier 1981, Arruda et al. 2016); Suriname (Tillier 1981, Arruda et al. 2016) Venezuela (Martens 1873, Baker 1925, 1926, Escarbassiere 1993); Guyana (Gibbons 1879, Tillier 1981); Peru (Tillier 1981, Ramirez, 1991; Ramirez et al. 2003) and Paraguay (Hylton-Scott & Lapuente 1968). Parodiz (1963) listed Omalonyx specimens from Paraguay, Argentina and Bolivia that were deposited in different institutional collections. Cazzaniga (1985), based on a bibliographic review, concluded that the known distribution area for O. unguis is southern Brazil, northern and eastern Argentina, Uruguay, Paraguay, and Bolivia and that the presence of O. unguis in the west of Argentina is known only in Tucumám (Hylton-Scott 1971) and Catamarca Provinces. The latter represents a new record made by Cazzaniga (1985) himself. Arruda & Thomé (2008b) showed that the distributions of O. convexus and O. unguis overlap in the Argentinean area of the Paraná River hydrographic region and adjacent localities in Uruguay. Gutiérrez Gregoric et al. (2013) recorded the occurrence of Omalonyx sp. in Misiones Province, Argentina using data from the La Plata Museum Mollusk Collection, literature and his own field work. For further literature data about Omalonyx occurrence in Argentina see Table 3. There are some records of Omalonyx in Chile (Odhner 1922, Letellier et al. 2003, 2014), and some of them are recent. However, in 1981, Tillier studied specimens from Chile that were identified as O. gayana and stated that, despite its limaciform shape, the species belongs to the genus Succinea. The recent records from Chile (Letellier et al. 2003, 2014) do not include a description of the specimens nor any discussion on this taxonomic issue related to Chilean succineids. Thus, we suppose that the specimens are in fact Succinea gayana.

The distribution of the genus in the Lesser Antilles is also well documented. Succinea haliotidea Mittre 1841 was found in Martinique by Mittre (Tillier 1981). However, Tillier (1981) did not include this species in the genus Omalonyx, and indicates that they do not even belong to the family Succineidae once neither he nor Fischer found any Omalonyx in Martinique. Therefore, we did not include Martinique within the occurrence area of Omalonyx. Hermann & Dundee (1967) studied Omalonyx from Sta. Lucia and Antigua, both in the Lesser Antilles. Other authors have also worked in this region. Patterson (1971) and Tillier (1981) studied specimens from Antigua, and Robinson et al. (2009) recorded the occurrence of Omalonyx in several localities in Dominica. Arruda et al. (2016) showed new records of O. geayi and extended the range of distribution of this species in South America to include Suriname, Ecuador, and Bolivia. All references and localities are in Table 3.

2. Records from institutional collections

Based on data of Brazilian institutional collections obtained through literature, museum databases or onsite research, we verified 21 records for the genus in the North region of the country, 28 in the Northeast, four in the Central West, 33 in the Southeast and 31 in the South (Table 2). Specimens were found in eight Brazilian institutional collections (INPA, MCP, MCNZ, MZSP, MNRJ, UFS, ZUECA and CMIOC). Among the institutional collections that were visited, two of them did not present specimens belonging to the genus (MIRR and MPEG) in (Table 1). Brazilian specimens of Omalonyx were also registered in six foreign institutional collections (ANSP, FMNH, BMNH, ZMB, MNHN, and MCZ). We also investigated the presence of Omalonyx in other South American countries and Lesser Antilles using engines for virtual searching in databases from Brazilian (CMIOC, MCP, MZSP, MNRJ) and foreign institutional collections (ANSP, BMNH, USNM, CM, MACN, MLP) (Table 3).

3. Malacological surveys in Brazil

Specimens of Omalonyx were sampled across Brazilian hydrographic regions, and the sites were classified above according to the presence or absence of Omalonyx spp. (Table 2 and 5).

Table 5
Surveyed sites within the Brazilian administrative regions where Omalonyx spp. was absent.

Administrative regions	Locality	Coordinates
Distrito Federal	Brasília	15° 51’36”S, 47° 52’20” W
		15° 50’21”S, 47° 54’26”W
		15° 50’41”S, 47° 54’59”W
		15° 44’26”S, 47° 52′52”W
	Brazlândia	15° 42’49”S, 48° 12’14”W
Tocantins	Palmas	10° 12’34”S, 48° 19’21”W
		10° 13’18”S, 48° 21’51”W
		10° 07’49”S, 48° 18’25”W
	Porto Nacional	10° 41’54”S, 48° 24’39”W
		10° 44’39”S, 48° 26’06”W
		10° 46’04”S, 48° 24’50”W
	Lagoa da Confusão	10° 47’54”S, 49° 37’21”W
		10° 43’50”S, 49° 32’27”W
Roraima	Boa Vista	02° 48’30”N, 60° 44’27”W
	Anauá Park	02° 49’52”N, 60° 40’47”W
	Caracaraí	01° 25’16”N, 60° 59’17”W
	Estação Ecológica de Viruá	01° 29’24”N, 61° 00’07”W
	Maloca da Raposa	03° 50’25”N, 59° 58’24”W
	Mucajaí	02° 41’05”N, 61° 12’56”W
	Villa Villena	02° 12’30”N, 60° 05’06”W
	Igarapé do Fogo	02° 18’53”N, 60° 04’56”W
	Taboca	02° 27’25”N, 60° 12’32”W
	Açude do Barroso	02° 30’38”N, 60° 17’54”W
	Tepequém	03° 41’31”N, 61° 42’41”W
	Alto Alegre	02° 53’54”N, 61° 29’30”W
	Caracaranã Lake	03° 46’21”N, 59° 50’02”W
	Estação Ecológica de Maracá	03° 22’51”N, 61° 26’13”W
		03° 22’13”N, 61° 26’13”W
		03° 21’46”N, 61° 25’59”W
	Serra do Murupu	03° 08’55”N, 60° 40’54”W
	Localities known only from the coordinates	04° 11’46”N, 60° 47’56”W
		03° 51’42”N, 60° 12’58”W
		02° 55’37”N, 60° 42’57”W
		03° 05’18”N, 60° 52’52”W
		02° 14’38”N, 60° 06’13”W
		02° 16’58”N, 60° 05’16”W

3.1. Surveyed sites with Omalonyx spp. presence

Specimens were collected in all Brazilian geographic regions, and we found Omalonyx in three States of the South region (Rio Grande do Sul, Santa Catarina, Paraná) where six localities were sampled, one State in the Southeast region (Minas Gerais) where seven localities were sampled, two States in the Central-west region (Mato Grosso, Mato Grosso do Sul) where four localities were sampled, five States in the Northeast region (Piauí, Ceará, Rio Grande do Norte, Pernambuco and Bahia) where nine localities were sampled, and five States (Acre, Amazonas, Pará, Rondônia and Amapá) in the North region where 15 localities were sampled. Among these localities, we made new records for four Brazilian States: Acre, Rondônia, Amapá and Piauí. All coordinates for 41 surveyed sites are listed in Table 2 and indicated in the map (Figure 1).

3.2. Surveyed sites with Omalonyx spp. absence

Despite the surveying effort, there were no records of Omalonyx spp. in three States: Distrito Federal (Central-west region), Tocantins and Roraima (North region). The coordinates are shown in Table 5.

4. Modeling of species distributions

The potential distribution of each species is indicated in the maps (Figure 2) where different colors and color densities are related to different probabilities of occurrence of suitable conditions for their presence. The environmental model applied here agrees with the data on species distribution (Figure 1) and supports geographic constraints on the species. Some species presents overlapping ranges of distribution. This is the case for O. matheroni, O. pattersonae and O. geayi, which tend to occur in tropical areas within the northern half of South America (Figure 2A, B and C) and for O. convexus and O. unguis, which tend to occur in temperate areas in the southern half of South America (Figure 2 D and E). Omalonyx matheroni, O. pattersonae and O. geayi present moderate probability of occurrence in a vast area within northern South America, merged with intermittent areas of high probability of occurrence (Figure 2A, B and C). Omalonyx convexus and O. unguis present a smaller area of occurrence; however, there are many regions of high probability of occurrence.

Figure 2
Potential distribution of Omalonyx species modeled with Bioclim analyses using all 19 bioclimatic variables, altitude and the full dataset showed on tables 2 and 3. (A) Omalonyx matheroni; (B) Omalonyx pattersonae, (C) Omalonyx geayi, (D) Omalonyx convexus, (E) Omalonyx unguis. The numbers represents the mainwatersheds within South America. The hydrographic regions are indicated by numbers: 1) Pacific Coast; 2) Caribbean sea; 3) Orinoco River; 4) Amapá-Esequibo; 5) Amazon River; 6) Tocantins River; 7) North Atlantic; 8) São Francisco River; 9) Eastern Atlantic; 10) Del Plata; 11) Border strip of the Brasilica (North) and the Chilean-Patagonian (South West) Subregion; 12) Eastern; 13) Chilean-Patagonian Subregion of the Pacific Versant; 14) Chilean-Patagonian Subregion of the Atlantic Versant.

There was a high probability of occurrence of O. matheroni in the Lesser Antilles, in the central region of South America (hydrographic region 5 and 10), in the Atlantic coast (hydrographic region nine), and in the south of South America (hydrographic region 13) (Figure 2A). These areas are predominantly tropical; however, there are also some temperate areas.

Omalonyx pattersonae showed a high probability of occurrence in tropical and arid regions (Figure 2B) in hydrographic region one, two and three (at isolated points in arid regions within hydrographic regions two and three) and in hydrographic regions six, seven and eight (in tropical and arid regions). Moderate probabilities of occurrence of O. pattersonae were observed in hydrographic regions nine and five (tropical region), where discontinuous areas of high probability of occurrence were observed in the Amazonian region (tropical and arid region) (Figure 2B).

Omalonyx geayi is a predominantly tropical species that can also occur in arid areas with high probability of occurrence within hydrographic regions one, two, three, four and five (Figure 2C). In hydrographic region five there are several small areas of high probability of occurrence merged in a vast area of moderate probability. There are areas of moderate probability of occurrence of O. geayi in hydrographic regions six, seven and 13.

Temperate areas along the southeast of South America present the highest probability of O. convexus occurrence. Areas with high probability of occurrence are within hydrographic regions 10, 12 and 13 (Figure 2D). There is moderate probability of occurrence in a vast area of hydrographic region 10 and in small areas within hydrographic regions 11 and 13.

Temperate areas in the southeast of South America that presented high probability of O. unguis occurrence includes hydrographic regions 10, 11, 12 and 13 (Figure 2E). Some areas within tropical (hydrographic regions five, nine and 10), arid (hydrographic region 11) and temperate areas (hydrographic region 14 and Malvinas Islands) were considered to have moderate probability of occurrence.

The PCA analysis resulted in three layers with highest eigenvalues that better explain the relationship between the variables in the selected study area. The most representative variables within these PCA-analysis axes were BIO4 (Temperature seasonality), BIO12 (Annual precipitation), and Altitude. As a consequence, the modeling of the species of Omalonyx was strongly influenced by these three variables, and their potential distribution was mainly determined by them. There is only one record of O. brasiliensis, thus, it was not possible to model this species' distribution due to technical limitations.

Discussion

This work addresses Omalonyx species distribution. The genus has a widespread Neotropical distribution, covering most South American hydrographic regions (except hydrographic regions one and 14) and the Lesser Antilles. The species occurrence map and the model of species distribution showed that three species are related to the north of South America (O. matheroni, O. pattersonae, O. geayi) and Lesser Antilles, and three species are related to the south of South America (O. unguis, O. convexus, O. brasiliensis).

Omalonyx matheroni is the most widespread species, and its distribution is more concentrated in northern South America (North and Northeast of Brazil, Guyana, French Guiana and Suriname) and in the Lesser Antilles. Omalonyx matheroni occurs in all Brazilian hydrographic regions. The most southern record for this species is Santa Catarina State in the south of Brazil (12, Figure 1).

Among northern species, O. matheroni is the most widespread. On the other hand, the records for O. geayi and O. pattersonae are discontinuous. Despite a huge area with high or intermediate probability of occurrence (Figure 2), the records for O. pattersonae and O. geayi are sparser (Figure 1). Omalonyx geayi was known to occur only in Kaw Swamp, French Guiana, the type locality (Tillier 1981). However, new records published recently expanded its distribution to Ecuador, Bolivia, Suriname and some localities in Brazil (Arruda et al. 2016). In this work, we recorded O. pattersonae for the first time in three hydrographic regions in North and Northeast of Brazil. There is one state in Brazil (Amazon State) where all three of these species occur at sites that are very close.

The other three species (O. unguis, O. convexus, O. brasiliensis) are concentrated in the south of South America. Among these species O. unguis reaches the most northern positions. This species was even found outside its distribution range (Lesser Antilles, Bolivia, Peru and in Ceará State, in the Northeast of Brazil). Omalonyx convexus records are very concentrated (Figure 1) and are restricted to sites where high or intermediate probability of occurrence was predicted (Figure 2B). However, there are some exceptions, and the species was also recorded in the north shore of Venezuela and in the Northeast of Brazil (Sergipe State). Until now, O. brasiliensis was known only from its type locality in Rio Grande do Sul State, Brazil. Despite all the surveying efforts already concentrated in Rio Grande do Sul State (Figure 1), O. brasiliensis was never found again since its description and the species remain known only for the type specimens from an unspecified site that could be related to hydrographic region 10 or 12 (Figure 1). Thus, O. brasiliensis remains to be rediscovered. This is a large State where O. convexus is widespread (Table 2, Figure 1); thus, both species may occur in sympatry.

There are several records from literature review, museums and collections that were not identified to species level and are designated Omalonyx sp. They were not used to model species distribution. These records are widespread throughout South American hydrographic regions (e.g., five, seven, nine and 10) and should also be carefully analyzed in future studies. On the other hand, some records identified to species level seem to be inconsistent (e.g., O. convexus was recorded for the Northeast of Brazil) and should be revised. All the records situated outside the area predicted for the species distribution should be carefully investigated. We suppose that the lack of taxonomists dealing with this group is the main cause for the great amount of records identified to genus level. On the other hand, the lack of training and the subtle morphological differences among species must be a cause of misidentification. These problems contribute to gaps in the knowledge regarding Omalonyx distribution (Tillier 1981, Coscarelli & Vidigal 2011).

Brazil is the best-sampled region in South America. Here, based on our malacological surveys, new records were made in Acre, Rondônia, Piaui, and Amapa. However, despite the absence of records even after intensive surveys in some administrative unities (Roraima, Tocantins and Distrito Federal) (Table 5), the genus was registered in all Brazilian hydrographic regions. There were no records for the central area of Tocantins River hydrographic region (surveyed sites: Palmas and other surrounding areas such as Lagoa da Confusão and Porto Nacional). However, the genus was present in the upper part of the hydrographic region (comprising Goiás and Pará States; Figure 1 and Table 2). Distrito Federal is an administrative unity that encompasses a small area when compared to the Brazilian States, and within this small area, there are the frontiers of three hydrographic regions: Tocantins River, São Francisco River and Del Plata. Despite its proximity to Goiás State where we found Omalonyx sp., there were no records in Distrito Federal (surveyed sites: the margins of Paranoá Lake, in Brasília, and in Brazlândia, all of them in the upper Del Plata hydrographic region where the genus is widely distributed; Figure 1). In Roraima State, northern Brazil, despite the surveying efforts (23 records of absence) no record was made. Roraima is within the Amazon River hydrographic region in which Omalonyx is widely distributed (Figure 2). However, all these negative localities are in the northeastern quadrant of Roraima, which is characterized by unusual vegetation, a seasonally flooded savannah, locally called “Lavrado” (Barbosa et al. 2007), which may have some ecological features that prevent Omalonyx spp. colonization. Future sampling efforts should focus on areas within these States that were not investigated until now. Considering that Omalonyx spp. occur in the hydrographic regions that cover these States, the absence of records is probably due to insufficient sampling effort.

In South America Omalonyx species were found in all hydrographic regions (except hydrographic regions one and 14) and countries. However, there were only isolated records in Colombia, Ecuador and Chile, indicating the need for more sampling effort in these areas (Figure 1). However, the occurrence of this genus in Chile must be further investigated due to different point of views regarding the identification of the Chilean slug-like succineids (Tillier 1981). The record from Chile (Letellier et al. 2014) should be carefully investigated since Tillier (1981) considered that the species recorded in Chile, O. gayana, belongs to the genus Succinea. In fact, Chile is separated from the other South American countries by the Andes mountain range, which is the major water divider in South America. d’Orbigny (1837) stated that the genus occurs only on the east side of the ridge, and until now, there is no evidence suggesting otherwise. Our results agree with those from d’Orbigny (1837) and Tillier (1981). Bioclimatic analysis proved to be a valuable tool for gaining insight into the geographical distribution of a species, especially when few records are available (i.e., O. geayi and O. pattersonae). Predictions showed that O. matheroni and O. geayi are tropical species. Omalonyx pattersonae usually occurs in arid regions; however, its distribution moderately extends over tropical areas. However, the prediction of O. geayi to hydrographic region 13 (temperate and very cold area) could be related to low numbers of records. In fact, bias can occur if species are insufficiently sampled. Thus, climatic envelopes may generate incomplete results, and the accuracy of predicted distributions will be decreased (Beaumont et al. 2005).

The occurrence records and the predictions both indicated that O. convexus and O. unguis have largely overlapping distributions in temperate areas within southern South America. These results are in accordance with those from Arruda & Thomé (2008b) and Coscarelli & Vidigal (2011). However, the distribution of O. convexus is constrained to temperate regions while O. unguis is well represented in tropical, temperate and arid regions indicating that the latter presents a broader tolerance range for environmental variables and is adapted to different bioclimatic conditions.

Considering the extension and the great diversity of habitats in the neotropical region and the wide occurrence area of Omalonyx species, bioclimatic models can be used to extrapolate information on species distribution if the high cost of field surveys in such a vast area is unfeasible. Information on the distribution of Omalonyx species will help to improve the taxonomic and biogeographic studies on these slug-like gastropods.

Acknowledgements

We are grateful to all colleagues that collected and sent material from different localities: Silvana Thiengo, Mônica Fernandez, Jean P. Pointier, Andrea Roche, Diego E. Gutierrez, Fernando S. Bezerra, José Cassimiro, Henry P. Lima, Felipe S. F. Leite and Villand Bergerhoff. We are also grateful to the curators of the institutional collections Célio Magalhães (INPA), Luiz R. Simone (MZSP), Arnaldo Coelho and Norma Salgado (MNRJ), Alejandra Rumi (MLP). Special thanks to Sílvia Gandolfi and Sônia Buck for the valuable support, to Daniel M. Pimpão, Fernando I. Martins, Linus Spatz and Mônica Tassara for important assistance in field collections, Adalberto dos Santos and Jennifer T. M. Andrade for text review. This work was partially supported by grants from FAPEMIG.

References

• AGUDO-PADRON, A.I. 2008. Listagem sistemática dos moluscos continentais ocorrentes no Estado de Santa Catarina, Brasil. Comun. Soc. Malacol. Urug. 9(91):147-179.
• AGUDO-PADRON, A.I. 2012. Nuevos aportes a la lista sistemática de moluscos continentales ocurrentes en el Estado de Santa Catarina, Brasil. Amici Molluscarum. 20(1):35-42.
• ARAÚJO, M.B. & RAHBEK, C. 2006. How does climate change affect biodiversity? Science. 313:1396-1397.
• ARRUDA, J.O., BARKER, G.M. & THOMÉ, J.W. 2016. Revaluation of the taxonomic characters and distribution of Omalonyx geayi Gastropoda, Succineidae). Iheringia, Sér. Zool. 106:2016019.
• ARRUDA, J.O., GOMES, S.R., RAMÍREZ, R. & THOMÉ, J.W. 2006. Morfoanatomia de duas espécies do gênero Omalonyx (Mollusca, Pulmonata, Succineidae) com novo registro para Minas Gerais, Brasil. Biociências. 14:61-70.
• ARRUDA, J.O. & THOMÉ, J.W. 2008a. Synonymization of Neohyalimax, Simroth, 1896 and Omalonyx d’Orbigny, 1837, with redescription of Omalonyx brasiliensis (Simroth, 1896) (Gastropoda: Succineidae). The Nautilus 122:96-98.
• ARRUDA, J.O. & THOMÉ, J.W. 2008b. Revalidation of Omalonyx convexus (Hynemann 1868) and emendation of the type locality of Omalonyx unguis (Orbigny 1837). Arch. Moll. 137:159-166.
• ARRUDA, J.O. & THOMÉ, J.W. 2011. Biological aspects of Omalonyx convexus (Mollusca, Gastropoda, Succineidae) from the Rio Grande do Sul State, Brazil. Biotemas. 24 (4):95-101.
• ARRUDA, J.O., PEREIRA, D., BERGONCI, P.E.A., SANTOS, C.P. & MANSUR, M.C.D. 2009. Novos registros de Omalonyx matheroni (Potiez & Michaud, 1835) (Mollusca: Gastropoda: Succineidae) para os Estados de São Paulo e Paraná, Brasil. Biotemas. 22:187-190.
• BAKER, H.B. 1925. The Mollusca collected by the University of Michigan-Williamson Expedition in Venezuela, Part III: Pupillidae to Oleacinidae. Occas. Pap. Mus. Zool. Univ. Mich. 156:1-56.
• BAKER, H.B. 1926. The Mollusca collected by the University of Michigan-Williamson Expedition in Venezuela, Part IV. Occas. Pap. Mus. Zool. Univ. Mich. 157:1-65.
• BARBOSA, R.I., CAMPOS, C., PINTO, F. & FEARNSIDE, P.M. 2007. The “Lavrados” of Roraima: Biodiversity and conservation of Brazil’s Amazonian Savannas. Func. Ecosyst. Commun. 1:29-41.
• BARKER, M.G. 2001. Gastropods on land: phylogeny, diversity and adaptive morphology. In The biology of terrestrial mollusks (M.G. Barker, ed.). CABI Publishing, New York, USA, p. 1-146.
• BEAUMONT, L.J., HUGHES, L. & POULSEN, M. 2005. Predicting species distributions: use of climatic parameters in BIOCLIM and its impact on predictions of species’ current and future distributions. Ecol. Model. 186:250-269.
• BONETTO, A.A. 1994. Austral rivers of South America. In Limnology now: a paradigm of planetary problems (Margaleff R. ed.). Elsevier Science, Amsterdam, n. 17, p. 425-472.
• BRADIE, J. & LEUNG, B. 2017. A quantitative synthesis of the importance of variables used in MaxEnt species distribution models. J. Biogeogr. 44:1344-1361.
• CANTANHEDE, S.P.D., FERNANDEZ, M.A., MATTOS, A.C., MONTRESOR, L.C., SILVA-SOUZA, N. & THIENGO, S.C. 2014. Freshwater gastropods of the Baixada Maranhense Microregion, an endemic area for schistosomiasis in the State of Maranhão, Brazil: I - qualitative study. Rev. Soc. Bras. Med. Trop. 47:79-85.
• CAZZANINGA, N.J. 1985. Anotaciones sobre algunos gasterópodos no marinos de la Argentina. Comun. Soc. Malacol. Urug. 6:329-331.
• COSCARELLI, D. & VIDIGAL, T.H.D.A. 2011. Mollusca, Gastropoda, Succineidae, Omalonyx unguis (d’Orbigny, 1835): Distribution extension and new records for Brazil. Check List. 7:400-403.
• COSTA, G.C., NOGUEIRA. C., MACHADO, R.B. & COLLI, G.R. 2010. Sampling bias and the use of ecological niche modeling in conservation planning: a field evaluation in a biodiversity hotspot. Biodivers. Conserv. 19:883-899.
• D’ORBIGNY, A. 1835a. Synopsis terrestrium et fluviatilum molluscorum, in suo per americam meridionalem itinere, ab A. d’Orbigny, collectorum. Mag. Zool. 5:1-44.
• D’ORBIGNY, A. 1835b. Voyage dans L’Amerique Méridionale: Mollusques. v.5, Partie 3 – Planches. P. Bertrand, Paris, France.
• D`ORBIGNY, A. 1837. Voyage dans L’Amerique Méridionale: Mollusques. v.5, Partie 3. P. Bertrand, Paris, France.
• DUTRA-CLARKE, A.V.C., WILLIAMS, C., DICKSTEIN, R., KAUFER, N. & SPOTILA, J.R. 2001. Inferences on the phylogenetic relationships of Succineidae (Mollusca, Pulmonata) based on 18S rRNA gene. Malacologia. 43:223-236.
• EDUARDO, J.M., TAKAHASHI, F.Y., HOLCMAN, M.M., DA COSTA, C.B.T.L. & OHLWEILER, F. 2012. Freshwater gastropods and helminthes associated, in water collections from Santo André, São Paulo, Brazil. Biociências. 18:22-34.
• ELITH, J., PHILLIPS, S.J., HASTIE, T., DUDÍK, M., CHEE, Y.E. & YATES, C.J. 2011. A statistical explanation of MaxEnt for ecologists. Divers. Distrib. 17(1):43-57.
• ESCARBASSIERE, R.M. 1993. Nota acerca de la presencia de la babosa Omalonyx (O.) pattersonae Tillier, 1981 (Gastropoda-Pulmonata Succineidae) en Venezuela. Acta Biol. Venez. 14:65-69.
• FRANCESCHINI, M.C., POI DE NEIFF, A. & GALASSI M.E. 2010. Is the biomass of water hyacinth lost through herbivory in native areas important? Aquat. Bot. 92:250-256.
• GARCIA, M.V.B., ARRUDA, J.O., PIMPÃO, D.M. & GARCIA, T.B. 2012. Ocorrência e controle de lesmas do gênero Omalonyx (Gastropoda, Succineidae), pragas de capim-elefante Pennisetum purpureum (Poaceae) em Rio Preto da Eva, Amazonas. Acta Amaz. 42(2):227-230.
• GIBBONS, J.S. 1879. Comparison of Omalonyx unguis, D’Orb. with O. felina, Guppy. J. Conchol. 2:99-101.
• GUTIÉRREZ GREGORIC, D.E., NÚÑEZ, V., VOGLER, R.E., BELTRAMINO, A.A. & RUMI, A. 2013 Gasterópodos terrestres de la provincia de Misiones, Argentina. Rev. Biol. Trop. 61(4):1759-1768.
• HAAS, F. 1939. Zur Kenntnis der Binnen-Mollusken NO - Brasiliens. Senckenb. Biol. 21:254-278.
• HERMANN, P.W. & DUNDEE, D.S. 1967. Notes on Omalonyx Sterkiana. 28:1-6.
• HERRMANNSEN, N.A. 1849. Indicis generum malacozoorum primorida. v.2. Theodore Fischer, Cassells, Ortmann, Berlin.
• HEYNEMANN, F.D. 1868. Die Mundtheile einiger brasilianischen Land- und Süsswasserschnecken. Malakozool. Blätter 15:99-113.
• HIDALGO, J.G. 1869. Moluscos del viaje al pacífico verificado de 1862 á 1865 por una comisión de naturalistas enviada por el gobierno español. Parte primera, Univalvos terrestres. Imprenta de Miguel Ginesta, Madrid, Spain.
• HIDALGO, J.G. 1870. Catalogue des coquilles terrestres recueillies par naturalistes de la commission scientifique espagnole sur divers points de l’Amérique méridionale. J. Conchol. 18:27-70.
• HIDALGO, J.G. 1872. Moluscos del viaje al pacífico verificado de 1862 a 1865 por uma comision de naturalistas enviada por el gobierno español. Parte primera, Univalvol terrestres. Madrid: Imprenta de Miguel Ginesta.
• HYLTON-SCOTT, M.I. 1971. Homalonyx weyrauchi, Nueva especie de Tucuman. Neotropica. 17:12-14.
• HYLTON-SCOTT, M.I. & LAPUENTE, E. 1968. Valor diagnostico de la Radula para especies del genero Omalonyx Orbigny. Neotropica 14:49-56.
• JESUS, L.S. & MANSO, C. L.C. 2010. Inventário da coleção de referência de moluscos terrestres e límnicos do LABIMAR, Campus Prof. Alberto Carvalho da Universidade Federal de Sergipe. Scientia Plena. 6(12):121001.
• LANGE DE MORRETES, F. 1949. Ensaio de Catálogo dos Moluscos do Brasil. Arq. Mus. Para. 7:1-216.
• LETELIER, S.V., BAEZ, P.R., REBOLLEDO, A.U. & FABRES, A. C. 2014. Moluscos Terrestres Nativos y Exóticos del Archipiélago Juan Fernández (AJF) (Mollusca: Gastropoda). In Boletín del Museo Nacional de Historia Natural, Chile (Herman Núñez C. ed.). Editora Museo Nacional de Historia Natural Casilla, Santiago de Chile, n. 63, p.187-199.
• LESSON, M. 1838. Description d’une espèce nouvelle du genre Testacelle et synopsis d’une monographie de ce genre de Mollusques. Rev. Bras. Zool. 1:249-251.
• LUTZ, A. 1921. Obervações sobre o gênero Urogonimus e uma nova forma de Leucochloridium em novo hospedador. Mem. Inst. Oswaldo Cruz. 13:136-140.
• MALTCHIK, L., STENERT, C. KOTZIAN, C.B. & PEREIRA, D. 2010. Responses of freshwater molluscs to environmental factors in Southern Brazil wetlands. Braz. J. Biol. 70(3):473-482.
• MARTENS, E.V. 1868. Ueber südbrasilische Land und Süsswasser mollusken. Malakozool. Blätter. 15:169-217.
• MARTENS, E.V. 1873. Die Binnenmollusken Venezuela’s. In Festschrift zur Feier des hundertjahrigen Bestehens der Gesellschaft naturforschender Freunde zu Berlin (Ferd. D. Verlagsbuchhandlung ed.). Harrwitz & Grossmann, Berlin, Germany, p.157-225.
• MARTINEZ, R.E. 1993. Nota acerca de la presencia de la babosa Omalonyx (O.) pattersonae Tillier, 1981 (Gastropoda-Pulmonata: Succineidae) en Venezuela. Acta Biol. Venez. 14:65-69.
• MONTRESOR, L.C., VIDIGAL, T.H.D.A., MENDONÇA, C.L.G.F., FERNANDES, A.A., DE SOUZA, K.N., CARVALHO, O.S., CAPUTO, L.F.G., MOTA, E.M. & LENZI H.L. 2008. Angiostrongylus costaricensis (Nematoda: Protostrongylidae): migration rote in experimental infection of Omalonyx sp. (Gastropoda: Succineidae). Paras. Res. 103:1339-1346.
• MORICAND, S. 1836. Troisième supplément au mémoire sur les coquilles terrestres et fluviates de la Province de Bahia. Sociétéde Physique et d’Historie naturelle de Genève, Genébra, 7:415-446.
• MOZZER, L.R., MONTRESOR, L.C., VIDIGAL, T.H.D.A. & LIMA, W.S. 2011. Angiostrongylus vasorum: Experimental infection and larval development in Omalonyx matheroni. J. Parasitol. Res. 2011:1-4
• ODHNER, N.H. 1922. Mollusca from Juan Fernandez and Easter Island. In The Natural History of Juan Fernandez and Easter Island (C. Skottsberg ed.). Zoology. Almqvist & Wiksells, Uppsala, v.3, p.219-254.
• OLAZARRI, J. 1979. Los Moluscos plaga de los cultivos de “berro” en Salto, Uruguay. Comun. Soc. Malacol. Urug. 5: 63-69.
• OLIVEIRA, M.P. & ALMEIDA, M.N. 2000. Inventário preliminar dos Moluscos do Estado de Minas Gerais, Brasil. Strombus. 6:01-06.
• PARODIZ, J.J. 1957. Catalogue of the land Mollusca of Argentina. The Nautilus. 70:127-135.
• PARODIZ, J.J. 1963. Observaciones anatomicas sobre Omalonyx patera Doer., com una nota biografica acerca de Adolfo Doering (1848-1926). Sterkiana. 12:1-7.
• PATTERSON, C.M. 1971. Taxonomic studies of the land snail family Succineidae. Malacol. Rev. 4:131-202.
• PEEL, M.C., FINLAYSON, B.L. & MCMAHON, T.A. 2007. Updated world map of the Koppen-Geiger climate classification. Hydrol. Earth Syst. Sci. Discuss. 4:439-473.
• PHILLIPS, S.J., DUDIK, M. & SCHAPIRE, R.E. 2004. A maximum entropy approach to species distribution modeling. In Proceedings of the Twenty-First International Conference on Machine Learning (C. Brodley coord.). Banff, Alberta, Canada, p. 655-662.
• PIMPÃO, D.M. 2007. Moluscos. In Biodiversidade do médio rio Madeira: bases científicas para propostas de conservação (L.H. Rapp Py-Daniel, C.P. Deus, A.L. Henriques, D.M. Pimpão, O.M. Ribeiro eds). INPA/MMA/MCT Manaus, Brazil, p. 69-81
• POI DE NEIFF, A., NEIFF, J.J. & BONETTO, A. 1977. Enemigos naturales de Eichhornia crassipes en el nordeste argentino y posibilidades de su aplicación el control biológico. Ecosur. 4:137-156.
• POTIEZ, V.L.V. & MICHAUD, A.L.G. 1835. Galerie des Mollusques, ou catalogue méthodique, descriptif et raisonné, de mollusques et coquilles du muséum de Douai. J.B. Baillière, Paris, France.
• RAMIRES, R. 1991. Primer registro de los géneros Adelopoma Doering, 1884, Ceciloides Férussac, 1814, Pupisoma Stoliczka, 1873 y Omalonyx D`Òrbigny, 1841 (Mollusca, Gastropoda) para el Perú. Puclicaciones Del Museo de Historia Natural Unmsm A, Lima, Perú, n.41, p. 5.
• RAMÍREZ, R., PAREDES, C. & ARENAS, J. 2003. Moluscos del Peru. Rev. Biol. Trop. 51 (3): 225-284.
• ROBINSON, D.G., HOVESTADT, A., FIELDS, A. & BREURE, A.S.H. 2009. The land Mollusca of Dominica (Lesser Antilles), with notes on some enigmatic or rare species. Zool. Meded. 83:615-650.
• RUBIO, G.D. & ACOSTA, L.E. 2011. Geographical distribution of the space-weaving spider, Chibchea salta, from northwestern Argentina: New records and bioclimatic modeling. J. Insect Sci. 11:54.
• SALGADO N.C. & COELHO. A.C.S. 2003. Moluscos terrestres do Brasil (Gastrópodes operculados ou não, exclusive Veronicellidae, Milacidae e Limacidae). Rev. Bio. Trop. 51:149-189.
• SCARABINO, F. 2003. Lista sistemática de los Gastropoda terrestres vivientes de Uruguay. Comun. Soc. Malacol. Urug. 8:203-214.
• SIMONE, L.R.L. 2006. Land and Freshwater molluscs of Brazil. EGB, Fapesp, São Paulo.
• SIMROTH, H. 1896. On Neohyalimax brasiliensis, n. gen., n. sp. (allied to Hyalimax), from Brazil. Proc. Malacol. Soc. Lond. 2:39-45.
• TILLIER, S. 1980. Gastéropodes terrestres et fluviatiles de Guyane française. Mém. Mus. Natl. Hist. Nat., Ser. A 118:1-188.
• TILLIER, S. 1981. South American and Juan Fernandez succineid slugs (Pulmonata). J. Molluscan Stud. 47:125-146.
• TIETZE, E. & DE FRANCESCO, C. G. 2012. Compositional fidelity of subfossil mollusk assemblages in streams and lakes of the southeastern pampas, Argentina. PALAIOS. 27 (6):401-413.
• TRAVASSOS, L.1928. Fauna helminthológica de Mato Grosso. Trematódeos – Parte I. Mem. Inst. Oswaldo Cruz 21:309-741.
• VERA-ARDILA, M. L. 2008. Lista de los géneros de moluscos terrestres de Colombia (Mollusca: Gastropoda: Prosobranchia: Mesogastropoda y Pulmonata: Stylommatophora). Biota Colombiana. 9:39-62.
• VOGLER, R. E., BELTRAMINO A. A., SEDE, M. M., GUTIÉRREZ GREGORIC, D. E., NÚÑEZ, V. & RUMI, A. 2013. The giant african snail, Achatina fulica (Gastropoda: Achatinidae): Using bioclimatic models to identify South American areas susceptible to invasion. Am. Malacol. Bull. 31(1):39-50.
• ZILLI F, L., MONTALTO, L. & MARCHESE, M. R 2008. Benthic invertebrate assemblages and functional feeding groups in the Parana´ River floodplain (Argentina). Limnologica. 38:159–171.

Publication Dates

• Publication in this collection
  2018

History

• Received
  24 July 2017
• Reviewed
  16 Oct 2017
• Accepted
  23 Dec 2017