First record of the nymph of Nanomis rasmusseni Chacon, Pescador & Segnini, 2013 (Ephemeroptera: Baetidae) from Colombia

Abstract

Herein, we present the first record of the nymph of Nanomis rasmusseni Chacón, Pescador & Segnini, 2013, from two biogeographic regions in Colombia. This species was originally described for the Venezuelan Andes. Both Colombian and Venezuelan populations occur at high elevations, in streams with similar altitudes. We also found that both populations can be distinguished from each other by the terga II, VII, and IX coloration, in addition to the branching pattern of the abdominal gills.

Key-Words.
Arthropoda; Distribution; Neotropical; Taxonomy

INTRODUCTION

NanomisLugo-Ortiz & McCafferty 1999 is a neotropical genus of Baetidae (Ephemeroptera) erected by Lugo-Ortiz & McCafferty (1999) based only on nymphal stages. The imaginal stage of Nanomis was subsequently described by Salles & Nieto (2008), based on specimens from Argentina. To date, only two species are known: N. galeraLugo-Ortiz & McCafferty 1999 occurring in Argentina, Bolivia, Colombia, Ecuador, and Perú (Domínguez et al., 2006), and N. rasmusseniChacón, Pescador & Segnini, 2013 known only in Venezuela (Chacón et al., 2013). In Colombia, Nanomis is widely distributed in the Andean region, occurring in the departments of Antioquia, Caldas, Cauca, Cundinamarca, Quindío, Nariño, Risaralda, Tolima, and Valle del Cauca (Lugo-Ortiz & McCafferty, 1999; Zuñiga et al., 2004; Dias et al., 2009; García-Alzate et al., 2010; Gutierrez & Reinoso, 2010; Forero-Céspedes & Reinoso, 2013; Forero-Céspedes et al., 2014). This work presents the first occurrences of N. rasmusseni from Colombia and reviews the geographical distribution of this species in South America.

MATERIALS AND METHODS

Immature stages of Nanomis were collected by using an aquatic entomological net and fixed in 96% ethanol. The identifications of the individuals were initially performed through external examination. Additionally, dissected parts of the specimens studied were observed under microscope and mounted on slides using Euparal as mounting media. Finally, the nymphs were determined taxonomically with the help of the original description of N. rasmusseni provided by Chacón et al., 2013.

Photographs were taken by using a stereoscopic Zeiss Stemi 2000c with an Axio Cam ERc 5s camera and edited with the Zen 2 lite and Photoshop CS5 programs. The material examined is deposited in the Entomological Collection of the Biology program at Universidad de Caldas (CEBUC) in Manizales, Colombia, and Collection of invertebrates from the laboratory of Ichthyology at Universidad del Quindío (IUQ) in Armenia, Colombia.

RESULTS AND DISCUSSION

Nanomis rasmusseni Chacón, Pescador & Segnini, 2013

Material examined: COLOMBIA: Nariño: Altaquer, Ñambi River - bridge on the road between Pasto and Tumaco, 01°16’00.08”N, 78°07’59.92”W, 1324 m.a.s.l., 03.ix.2007, three male nymphs and two female nymphs deposited in CEBUC. Quindío: Calarcá: Vereda Quebrada Negra, Alto Cauca, Quindío River basin, Santo Domingo River, 04°30’36.5”N, 75°36’48.2”W, 1750 m.a.s.l., 12.vii.2009, two male nymphs and three female nymphs deposited in IUC.

Distribution: Venezuela, Central Andes and central and southern Colombia (Fig. 1).

Figure 1
Geographic distribution of Nanomis rasmusseni in South America.

Populations of N. rasmusseni in Venezuela and Colombia are found in freshwater environments at high elevations. In Venezuela, N. rasmusseni is known from two groups of streams: (1) One group located at altitudes ranging from 1700 to 3000 m.a.s.l., (2) and the second between 830 and 1650 m.a.s.l. (Chacón et al., 2013).

In Colombia nymphs of this species were found in creeks of two departments located in two different biogeographic areas. The first group was found in the Santo Domingo River in Alto Rio Cauca, located in the Andean region (1700 m.a.s.l.). The second was recorded in the Ñambi River, located in the Chocó biogeographic region (1324 m.a.s.l.).

Similar diagnostic characters were found in nymphs analyzed in Colombia and Venezuela: (1) Anterior margin of labrum with flattened triangular-shaped (like witch nails) setae arising medially (Fig. 2A); (2) inner set of incisors of right mandible with five denticles (Figs. 2B, D); (3) right prostheca bifid from the basal third (Figs. 2B, C); (4) posterior margin of abdominal terga I-VIII smooth, of terga IX-X with spines (Figs. 3A, B).

Figure 2
Nanomis rasmusseni, nymph. Mouthparts: (A) Labrum; (B) Right mandible; (C) Prostheca; (D) Inner set of incisors of right mandible (left).

Figure 3
Nanomis rasmusseni, nymph. Dorsal habitus of (A) Male and (B) Female.

We found morphological differences between color patterns of terga in male nymphs from Colombia and Venezuela. Specimens from Venezuela have a central region of terga uniformly whitish and tinged with brown at the anterior and posterior margins of terga (Fig. 15 from Chacón et al., 2013), the lateral area of specimens from Colombia have a pattern extensively tinged with brown, but with different patterns of spots in between which central and lateral lighter areas are observed (Fig. 3A). Tergum VII of the Venezuelan nymphs has a broadly whitish mark with marginal areas tinged with brown, while the tergum VII in Colombian nymphs are extensively tinged with brown; terga IX is uniformly tinged with brown in Venezuelan specimens and broadly whitish in the Colombian specimens (Fig. 2A). There are differences in branching gills between the populations from Colombia and Venezuela. In Venezuela, individuals have gills with slightly pigmented ramifications and brown shadow in the center, while in Colombia, individuals have gills more pigmented and completely clear ramifications.

ACKNOWLEDGEMENTS

We thank the Biology program of the Faculty of Basic Sciences at Universidad del Quindío in Colombia for the financial support for two research visits (during the second semester of 2015 and the second semester of 2016 to L.G.S.J.). Gratitude is also expressed to COLCIENCIAS and to Lucimar Gomes Dias (Universidad de Caldas) for reviewing the material.

REFERENCES

• Chacón, M.M.; Pescador, M.L & Segnini, S. 2013. New species of Nanomis. Lugo-Ortiz and McCafferty, 1999 (Ephemeroptera: Baetidae) from Venezuela. Aquatic Insects - International Journal of Freshwater Entomology, 35: 1-2, 1-14.
• Dias, L.G.; Zuñiga, M.C. & Bacca, T. 2009. Estado actual del conocimiento del orden Ephemeroptera en Colombia. In: Congreso Sociedad Colombiana de Entomología, 36º. Memorias. Colombia, Sociedad Colombiana de Entomología. p. 236-253.
• Domínguez, E.; Molineri, C.; Pescador, M.L.; Hubbard, M.D. & Nieto, C. 2006. Diversidad Acuática en América Latina. Vol. 2, Ephemeroptera de América del Sur. Sofia-Moscú, Pensoft.
• Forero-Céspedes, A.M. & Reinoso-Flórez, G. 2013. Estudio de la Familia Baetidae (Ephemeroptera: Insecta) en una cuenca con influencia de la Urbanización y Agricultura: Río Alvarado-Tolima. Revista de la Asociación Colombiana de Ciencias Biológicas, 25: 12-21.
• Forero-Céspedes, A.M.; Gutiérrez, C. & Reinoso-Flórez, G. 2014. Nuevos Registros de Baetidae (Ephemeroptera: Insecta) para el departamento del Tolima. Revista de la Asociación Colombiana de Ciencias Biológicas, 26: 59-67.
• García-Alzate, C.A.; Román-Valencia, C.; González, M.I. & Barrero, A.M. 2010. Composición y variación temporal de la comunidad de insectos acuáticos (Insecta) en la Quebrada Sardineros, afluente Rio Verde, Alto Cauca, Colombia. Revista de investigaciones Universidad del Quindío, 21: 21-28.
• Gutierrez, C. & Reinoso, G. 2010. Géneros de ninfas del orden Ephemeroptera (Insecta) del departamento del Tolima, Colombia: listado preliminar. Biota Colombiana, 11(1-2): 23-32.
• Lugo-Ortiz, C.R. & McCafferty, W.P. 1999. Three New Genera of Small Minnow Mayflies (Insecta: Ephemeroptera: Baetidae) from the Andean and Patagonia. Studies on Neotropical Fauna and Environment, 34: 88-104.
• Salles, F.F. & Nieto, C. 2008. The Adult Stages of Nanomis and Spiritiops (Ephemeroptera: Baetidae). Revista de la Sociedad Entomológica Argentina, 67: 35-39.
• Zuñiga, M.C.; Molineri, C. & Domínguez, E. 2004. El Orden Ephemeroptera en Colombia. In: Fernández, F.C.; Andrade-C., M.G. & Amat, G.D. (Eds.). Insectos de Colombia. Bogotá, Universidad Nacional de Colombia. v. 3, p. 17-42.

• 1
  Edited by: Marcelo Duarte da Silva
• Published with the financial support of the "Programa de Apoio às Publicações Científicas Periódicas da USP"
• 3
  Seção de Publicações - Museu de Zoologia da Universidade de São Paulo

Publication Dates

• Publication in this collection
  2018

History

• Received
  16 May 2017
• Accepted
  13 Apr 2018