Reproductive biology of the tarpon snook Centropomus pectinatus (Perciformes, Centropomidae) in estuarine waters in the south-western Atlantic.

The reproductive biology of Centropomus pectinatus is described from an artisanal fish landings collaborative monitoring programme between May 2012 and April 2013 in estuarine waters in north-eastern Brazil. The total length (LT ) at which 50% are mature was 24 cm, corresponding to 37·7% of the maximum recorded LT . Gonado-somatic indices were variable, but highest values were in June and August 2012. Length-frequency distributions showed male dominance in smaller length classes (15-30 cm) and females in larger length classes (>30 cm).

Reproductive biology of Haemulon plumierii in the south-western Atlantic Ocean's most extensive reefs: implications for fisheries management.

The reproductive biology of the white grunt Haemulon plumierii was studied from 360 individuals obtained from artisanal fisheries landings in the Abrolhos Bank, Brazil, between August 2010 and March 2012. The overall sex-ratio did not differ significantly from 1:1, although males predominated in larger size classes. ß-Binomial modelling of historical sex-ratio data indicated that the catch rate of females has increased in recent years. Females reached maturity at a smaller total length (LT ; 214 mm) than males (235 mm LT ) and the LT at which 50% of all individuals are mature (L50 ) was 220 mm, corresponding to 41·5% of the maximum recorded LT . Variation in the gonado-somatic index and in the relative frequency of reproductive stages indicates that reproduction occurs year round, with increased activity during the austral spring and summer. Fecundity was not size dependent. The reproductive parameters provided here can support management measures focussed on seasonal closures during spawning peaks (September to November and February to March) and minimum sizes (>L50 ) for the capture of this important artisanal fisheries resource in Abrolhos, the region with the largest and most biodiverse coralline reefs in the South Atlantic Ocean.

Sea-level variations have influenced the demographic history of estuarine and freshwater fishes of the coastal plain of Paraná, Brazil.

This study surveyed the mitochondrial haplotype diversity of nine freshwater fish species and two estuarine-marine species from the coastal basins and drainages of the highland plateaus of Paraná, Brazil. Portions of the cytochrome b gene or the control region were sequenced. The demographic history of each species was inferred using the Bayesian skyline method, mismatch distribution analysis and statistical neutrality tests. Demographic reconstruction analyses revealed a single pattern of variation in the effective population size (Ne ) among species. No dramatic changes in Ne were detected in upland species. By contrast, evidence of population expansion over the past 200 000 years was detected in all coastal plain and estuarine species. These findings correspond to periods of low sea-level (regressions) followed by a rapid increase in the sea-level by >100 m. The resulting reconnections and subsequent fragmentation and isolation between the estuarine and freshwater bodies were putatively relevant to the historical demography of the fish species in these areas.

Feeding ecology and trophic comparisons of six shark species in a coastal ecosystem off southern Brazil.

The diets of six shark species, Sphyrna lewini, Sphyrna zygaena, Carcharhinus obscurus, Carcharhinus limbatus, Rhizoprionodon lalandii and Galeocerdo cuvier, were investigated in a subtropical coastal ecosystem of southern Brazil. Stomach content data were obtained to assess foraging niche segregation and ontogenetic shifts in the diets of these sharks. Five of the shark species off the Paraná coast were ichthyophagous, with the exception of S. zygaena, which was teutophagous. With the exception of G. cuvier, which had a generalist diet, the other five species displayed specialization in their feeding. Ontogenetic shifts were observed in C. obscurus and S. lewini with large individuals consuming elasmobranchs. Owing to the diet overlap between C. obscurus and S. lewini, C. obscurus and C. limbatus and R. lalandii and C. limbatus, future studies on the spatial and temporal distributions of these species are needed to understand the extent of competitive interactions.

Molecular data reveal a diverse Astyanax species complex in the upper Iguaçu River.

Astyanax is among the most speciose genera in the Characidae. In this study, molecular markers were used to assess the extent to which some of the commonly recognized Astyanax species of the upper Iguaçu River correspond to natural groups. These results indicate that the diversity of Astyanax has been severely underestimated with several potential cryptic species.

Contribuição ao conhecimento da ictiofauna da Bacia do Alto Rio Iguaçu, Paraná, Brasil / Contribution to the knowledge of the ichthyofauna from the upper Iguaçu River Basin, Paraná, Brazil

Com base no material depositado no Museu de História Natural Capão da Imbuia é apresentado um levantamento atualizado da ictiofauna da Bacia do Alto Rio Iguaçu. O presente estudo detectou a presença de 41 espécies, das quais oito são endêmicas e dez apresentam status taxonômico ainda não definido. Três espécies são apresentadas pela primeira vez para a Bacia do Rio Iguaçu (Astyanax sp. n., Misgurnus anguillicaudatus e Clarias gariepinus), sendo que M. anguillicaudatus é espécie exótica muito comum em aquarismo e C. gariepinus é uma espécie exótica utilizada na piscicultura regional. Astyanax altiparanae é citada pela primeira vez para o Alto Iguaçu. Durante o presente levantamento, a espécie considerada rara Glandulocauda melanopleura foi registrada, e Hyphessobrycon taurocephalus, conhecida somente através da série tipo, não foi encontrada. Uma chave para identificação das espécies do Alto Iguaçu é apresentada.