Abstract in English:Oligosarcus jenynsii (Günther, 1864) and O. robustus Menezes, 1969 are fish species distributed in Rio Grande do Sul, Brazil, Uruguay, and northern Argentina. The reproductive period and recruitment, sex ratio, absolute and relative fecundity, and body length at first gonadal maturation of the two carnivorous species from Fortaleza Lagoon were analized. The specimens were sampled monthly, from May 2000 to April 2001, with fishing effort of 24 hours/month, using stationary gillnets of different mesh sizes and seine net (three samples per edge). The records of each individual included total length, total weight, gonad weight, sex and gonadal maturity stage. The reproductive period of both O. jenynsii and O. robustus ranges from May/June to November/December, according to the bimonthly variation of the mean values of gonosomatic index, and the relative frequencies of the gonadal maturation stages. Recruitment of new individuals to the population occurs from November/December to March/April. The sex ratio is different from 1:1 for O. jenynsii and similar to 1:1 for O. robustus. The mean absolute fecundity, calculated by counting sub-sampled oocytes from mature females, was 14,483 oocytes for O. jenynsii, and 16,308 oocytes for O. robustus. The first maturation curve shows that O. jenynsii begins to reproduce between 84 mm and 104 mm (total length), and O. robustus between 126 mm and 146 mm, probably at similar ages.
Abstract in English:A detailed preliminary histological analysis of Helobdella hyalina Ringuelet, 1942 male system from Los Talas, Buenos Aires, Argentina is described. Six pairs of testisacs, located between the crop caeca, form the male reproductive system. Each testisac is clothed by the mesotelium. Inside it, the germinal cells are connected to the citophore and develop functional unit called poliplast. The spermatozoa are released into testisacs after the reabsortion of the citophore. Five stages of spermatogenesis are described taking into account the successive maturation stages of germinal cells and the changes in the citophore size. Lining cells and gland cells were found in the seminal vesicle. Five different types of gland cells are placed inside the ejaculatory ducts, as well as two kinds of cells are found in its distal portion: type 1, which produces eosinophilic granular secretion, type 2, with amorphous and slightly eosinophilic. Three distinct gland cells are located in the proximal portion of the duct: type 3, which produces a strongly eosinophilic granular secretion; type 4, with a negative eosinophilic amorphous secretion and type 5, with a basophilic granular secretion. Type 5 gland cells are described for the ducts of this species only.
Abstract in English:Three new species of Cephalobium Cobb, 1920, C. laplata from City Bell, C. polidentatum from Lincoln and C. dispar from Gorina, parasites of Gryllodes laplatae Saussure, 1877 from Buenos Aires, Argentina, are described and illustrated. Cephalobium laplata can be differentiated by having the cheilostom with a dorsal unmovable tooth, telostom with three ventral little teeth and two ventral movable claw teeth and gubernaculum triangular and five pairs of genital papillae. Cephalobium polidentatum has cheilostom with a movable ventral tooth, prostom with four dorsal movable teeth and telostom with three teeth; gubernaculum triangular with projections and with one pair of preanal and six pairs of postanal papillae. Cephalobium dispar is characterized by having telostom with two wings around the spicules and one pair of preanal and six pairs postanal papillae.
Abstract in English:Otiothops lajeado sp. nov. and Fernandezina saira sp. nov., respectively from the states of Tocantins and Amazonas, Brazil, are described.
Abstract in English:The external features of egg, larva and pupa of Dryas iulia alcionea (Cramer, 1779) are described and illustrated.
Abstract in English:New taxa described: from Ecuador, Quirimbaua gen. nov., type species Q. castroi (Napo); from Colombia: Icupima taua (Cauca), Adesmus murutinga and Tyrinthia dioneae (Valle del Cauca), Essosthrutella acatinga and Hemilomecopterus gen. nov., type species, H. alienus (Amazonas). New records for Colombia are presented for Olivensa mimula Lane, 1965, Tyrinthia paraba Martins & Galileo, 1991, Amapanesia exotica (Martins & Galileo, 1991), Sibapipunga beckeri (Martins & Galileo, 1992), Juninia annulifera (Kirsch, 1889), Isomerida albicollis (Laporte, 1840), Adesmus diana (Thomson, 1860), A. pirauna Galileo & Martins, 1999, Phoebe concinna White, 1856 and Leucophoebe albaria (Bates, 1872). A key to the species of Essosthrutella is added.
Abstract in English:The sexual dimorphism in size, morphology and color of the lizard Liolaemus occipitalis Boulenger, 1885 was studied. Thirty-two adult males and twenty-eight adult females were sampled from a population in the Jardim do Éden beach, near Tramandaí, Rio Grande do Sul, Brazil. Size related sexual dimorphism occurred in all compared body dimensions. The largest female was 59.6 mm in snout-vent length, and the largest male was 69.3 mm. Males and females also presented differences in ventral and dorsal color pattern, and in the presence of pre-cloacal pores. The results suggest that, in Liolaemus occipitalis, sexual dimorphism in size is determined by sexual selection, competition between males and by the high energetic cost for females a few months after hatching.
Abstract in English:Male-male and male-female interactions, reproductive habitat, and vocalizations of Hyla goiana B. Lutz, 1968 a member of H. polytaenia species group, are described. Three groups of calling males were surveyed along a small stream, at the Estação de Pesquisa e Desenvolvimento Ambiental de Galheiro, Perdizes municipality, State of Minas Gerais, Brazil. The mean distance between the nearest calling neighbors was 2.7 m, in accordance with an uniform distribution. Clutches (mean 180 eggs) were deposited in the stream, submerged and attached to plants. In two observed courtships the female moved towards a calling male that rapidly clasped her. In the male-male interaction, the males emitted advertisement and encounter calls and then engaged in physical combat. The males have a prepollical fang-like spine on each hand and several of them were observed with scratches on dorsum. The advertisement call consists of alternating harsh notes and a trilled of brief notes. The frequency of the call is lower than that of H. aff. polytaenia and H. cipoensis B. Lutz, 1968. The clutch characteristics of H. goiana are similar to those described for H. polytaenia Cope, 1870 and H. cipoensis.
Abstract in English:The chromosomes of the cave millipede Pseudonannolene strinatii Mauriès, 1974 were investigated. The diploid chromosome number was found to be 2n=16, XX/XY; the C-banding technique revealed a large amount of heterochromatin while the silver staining technique (Ag-NOR) evidenced the presence of heteromorphism of the NORs in some cells.
Abstract in English:The diet of Leptodactylus ocellatus (L., 1758) was studied in specimens collected at Maldonado Department (Uruguay), where monthly surveys were made between August 1998 and March 2000. A total of 143 frogs were collected, measured, sexed, and dissected, to assess stomach contents. The anurans were grouped into three age classes and four categories (considering sex and capture date). The trophic amplitude for each age class and sex-season category was quantified using Shannon-Weaver Index, and the trophic niche overlap between ages and categories by using the Pianka Index. Comparisons among treatments were made by G-tests. The most important prey items were coleopterans (IRI = 2547), and significant correlations were found between predator and prey sizes. The major differences on diet composition were found between extreme age classes (froglets and adults). Significant differences were also detected between sexes in the cold season but not in the warm season. Any of these changes in diet may be related with the availability of prey.
Abstract in English:Aedes (Stegomyia) albopictus (Skuse, 1894) larvae were recorded for the first time in the internodes of bamboo cuts found in the Atlantic Forest in the State of Paraná, Brazil. The bamboo, Bambusa sp., was introduced in the area of Imbucuí-Mirim town, across the municipal district of Paranaguá and towards the interior of the Atlantic Forest. A total of 251 larvae of Aedes albopictus (37.9%), Culex (Microculex) spp. (13.9%), Limatus durhami Theobald, 1901 (39.8%), Toxorhynchites sp. (0.4%) and Wyeomyia spp. (8.0%) were collected from bamboo internodes filled with rain and from the terrestrial Bromeliaceae and epiphytas found near the bamboo bushes. Aedes albopictus was found in bamboo internodes containing 30 to 254 ml of rain, sometimes coexisting with Li. durhami. Borders of forest ecosystems should be characterized as risk areas for arbovirosis transmission, since they sustain the circulation of vertebrates and arthropodal hematophagus, not only in the wild but also in the anthropic areas.
Abstract in English:The relative growth of the fiddler crab Uca burgersi Holthuis, 1967 was analyzed in two populations from different mangroves (Ubatumirim and Cavalo rivers) in the southeastern Brazilian coast, monthly sampled from May, 2001 to April, 2002. The population from a high productivity level mangrove reaches the sexual maturity in larger sizes than the population from a less productive site. This results can be attributed to the greater amount of nutrients found in the Cavalo than in Ubatumirim mangrove.
Abstract in English:While all species of the genus Callinectes Stimpson, 1860 have a continuous distribution on the Atlantic coast of the Americas, Callinectes sapidus Rathbun, 1896 is the only one with disjunct distribution. Considering that this species was introduced in Europe and Japan, it has been suggested that the occurrence of C. sapidus on the southern coast of Brazil was due to the transport by ballast water. In the archaeological site Ariano Souza, located in the estuary of the Patos Lagoon (southern Brazil), remains of crustaceans, including claws of approximately two thousand years ago, were found. A preliminary analysis of this material showed Callinectes chelae. Because this archaeological site is located inside the estuary, it has been hypothesized that these chelae belong either to C. sapidus or to C. danae Smith, 1869. A comparison between pincers collected in the archaeological and pincers of these two species (90 dactyls, 30 of each type) was performed. The analysis (ANOVA) considered the variability of seven characters of the dactyls, and demonstrated the existence of two groups. Results showed that the measured characters suffice to separate these species, and indicated that the material found in the archaeological site belongs to C. sapidus. The hypothesis of the introduction of C. sapidus in the area is rejected. The possible biogeographic history of the species is discussed.
Abstract in English:The diet of four species of Anostomidae (Leporinus friderici Bloch, 1794, L. striatus Kner, 1858, L. elongatus Valenciennes, 1849 and Leporinus sp.) were investigated in the Manso Reservoir, Mato Grosso State, Brazil. Fish were sampled in three sites: upriver, in the main body of the reservoir, and below the dam. Were analized 276 stomachs. The diet was evaluated using the frequency of ocorrence and volumetric methods. Leporinus friderici showed tendency to herbivory, mainly in the upriver site. In the reservoir and below the dam, it consumed large quantities of fish; Isoptera only in the reservoir. Leporinus striatus and L. elongatus have similar diets, consuming Chironomidae larvae (Diptera), whereas Leporinus sp. was more generalist, feeding similar proportions of vegetable, detritus and insect (Chironomidae and Ephemeroptera). The mouths of the species have different positions: terminal in L. friderici, subterminal in L. elongatus and intermediate in L. striatus and Leporinus sp. The diet overlap values were low, except for L. friderici and Leporinus sp. (0.7) in the upriver, and L. striatus and L. elongatus (0.6) below the dam.
Abstract in English:Potamolithus catharinae Pilsbry, 1911 is characterized on specimens from Hercílio river, State of Santa Catarina, Brazil, type-locality. Conchology, conchometry, soft-part morphology including head and food complex, pallial structures, radula and some aspects of the female and male reproductive systems are provided.
Abstract in English:Heleobia robusta, new species from plain coast of Rio Grande do Sul, Brazil, is described. Conchology, conchometry, soft-part morphology including head-food, pallial structures, radula and some aspects of the female and male reproductive systems are provided.
Abstract in English:Abundance and diversity of the fish fauna in the shallow infralittoral region of Atami Beach, Paraná, Brazil, were studied through monthly collections between July 1998 and June 1999. A total of 7553 fishes from 70 species and 26 families, mainly juvenile forms, was captured in the area. The mean captures in number of species, number of fish and biomass were larger from the end of spring to the middle of autumn; seasonal tendency in richness, diversity (number) and equitability indices were not observed. The largest mean dissimilarity in the composition of the ichthyofauna occurred between June and May in comparison to the period between July and October. The species that contributed most to this dissimilarity were Selene setapinnis (Mitchill, 1815), Conodon nobilis (Linnaeus, 1758) and Stellifer rastrifer (Jordan, 1889). Three great groups reflecting patterns of temporal occurrence of the most abundant species were identified.
Abstract in English:Two new species of the genus Philoponella Mello-Leitão, 1917 are described: P. ramirezi, from the Atlantic forest of the State of Minas Gerais, Brazil, and P. pomelita, from the subtropical forests of the Province of Misiones, Argentina. Relationships of these new species are discussed.