Revisão taxonômica de Psalidodon eigenmanniorum (Cope) com base em análises morfométrica, merística e padrão de colorido (Characiformes: Characidae) / Taxonomic review of Psalidodon eigenmanniorum (Cope) based on morphometric and meristic analysis and color pattern (Characiformes: Characidae)

A identidade de Psalidodon eigenmanniorum (Cope, 1894) e a possibilidade de se constituir em mais de uma espécie é testada através de análises da morfometria (19 medidas), dos caracteres merísticos (14 contagens) e do padrão de colorido de 705 exemplares provenientes dos sistemas dos rios Tramandaí/Mampituba, da laguna dos Patos e drenagem do baixo rio Uruguai. Foram diafanizados e corados 40 exemplares. Os dados morfométricos foram utilizados na Análise de Componentes Principais, Análise Discriminante, Morfometria Geométrica e Função Discriminante. As análises foram feitas considerando os sexos em separado dentro de cada sistema hidrográfico, bem como comparando as populações entre os sistemas hidrográficos e finalmente no conjunto de sistemas representando a área de ocorrência da espécie. A partir dos dados analisados não foram encontradas diferenças entre os sexos. Os resultados mostraram variação morfológica que não sustenta o reconhecimento de possíveis espécies crípticas. A variação encontrada nos dados merísticos, morfométricos e no padrão de colorido justifica a redescrição da espécie. Os resultados das comparações entre as populações indicaram variações nesses caracteres indicando que a espécie possui considerável plasticidade fenotípica.(AU)

The identity of Psalidodon eigenmanniorum (Cope, 1894) and the possibility of constituting more than one species is tested through analyzes of morphometry (19 measurements), meristic characters (14 counts) and the color pattern of 705 specimens from the Tramandaí/Mampituba, from the Patos lagoon and from the lower Uruguay River drainage. Forty specimens were cleared and stained. Morphometric data were used in Principal Component Analysis, Discriminant Analysis, Geometric Morphometry and Discriminant Function. The analysis was carried out considering the sexes separately within each hydrographic system, as well as comparing the populations between the hydrographic systems and finally in the set of systems representing the area of occurrence of the species. No differences were found between the sexes in the analyzed data. The results showed morphological variation that does not support the recognition of possible cryptic species. The variation found in meristic, morphometric and color pattern data justifies the redescription of the species. The species is described to the aforementioned drainages, and the results demonstrate its phenotypic plasticity.(AU)

Hydrography rather than lip morphology better explains the evolutionary relationship between Gymnogeophagus labiatus and G. lacustris in Southern Brazil (Cichlidae: Geophagini)

Gymnogeophagus labiatus and G. lacustris have been long recognized as sister species exhibiting different ecological requirements. Gymnogeophagus labiatus occurs in rock bottom rivers in the hydrographic basins of Patos Lagoon (HBP) and Tramandaí River (HBT), while G. lacustris is exclusive from sand bottom coastal lagoons of the HBT. In this study, we used molecular markers, morphological measurements and data from nuptial male coloration to investigate the evolutionary relationship between these species in each hydrographic basin. We found, for all data sets, a closer relationship between G. labiatus and G. lacustris from the HBT than between G. labiatus populations from HBT and HBP. In particular, lip area had a large intraspecific plasticity, being uninformative to diagnose G. lacustris from G. labiatus. Molecular clock-based estimates suggest a recent divergence between species in the HBT (17,000 years ago), but not between G. labiatus from HBP and HBT (3.6 millions of years ago). Finally, we also found a divergent G. labiatus genetic lineage from the Camaquã River, in the HBP. These results show that the current taxonomy of G. labiatus and G. lacustris does not properly represent evolutionary lineages in these species.(AU)

Gymnogeophagus labiatus e G. lacustris vêm sendo consideradas espécies irmãs que possuem diferentes exigências ecológicas. Gymnogeophagus labiatus ocorre em rios de fundo de pedra nas bacias hidrográficas da Laguna dos Patos (HBP) e do rio Tramandaí (HBT), enquanto G. lacustris é exclusivo da HBT, ocorrendo em lagoas costeiras de fundo de arenoso. Nesse estudo, foram usados marcadores moleculares, medidas morfológicas e dados sobre a coloração nupcial em machos para investigar a relação evolutiva entre estas espécies em cada bacia hidrográfica. Para todos os conjuntos de dados foi observada uma relação mais próxima entre G. labiatus e G. lacustris da HBT do que entre as populações de G. labiatus da HBP e HBT. Em particular, a área do lábio teve uma grande plasticidade intraespecífica, não sendo informativa para diagnosticar G. lacustris de G. labiatus. Estimativas baseadas no relógio molecular sugeriram uma divergência recente entre as espécies da HBT (17.000 anos atrás), mas não entre as populações de G. labiatus da HBP e HBT (3,6 milhões de anos atrás). Finalmente, também foi encontrada uma linhagem genética de G. labiatus divergente no rio Camaquã, na HBP. Esses resultados mostram que a taxonomia atual de G. labiatus e G. lacustris não representa adequadamente as linhagens evolutivas nessas espécies.(AU)

Hydrography rather than lip morphology better explains the evolutionary relationship between Gymnogeophagus labiatus and G. lacustris in Southern Brazil (Cichlidae: Geophagini)

Gymnogeophagus labiatus and G. lacustris have been long recognized as sister species exhibiting different ecological requirements. Gymnogeophagus labiatus occurs in rock bottom rivers in the hydrographic basins of Patos Lagoon (HBP) and Tramandaí River (HBT), while G. lacustris is exclusive from sand bottom coastal lagoons of the HBT. In this study, we used molecular markers, morphological measurements and data from nuptial male coloration to investigate the evolutionary relationship between these species in each hydrographic basin. We found, for all data sets, a closer relationship between G. labiatus and G. lacustris from the HBT than between G. labiatus populations from HBT and HBP. In particular, lip area had a large intraspecific plasticity, being uninformative to diagnose G. lacustris from G. labiatus. Molecular clock-based estimates suggest a recent divergence between species in the HBT (17,000 years ago), but not between G. labiatus from HBP and HBT (3.6 millions of years ago). Finally, we also found a divergent G. labiatus genetic lineage from the Camaquã River, in the HBP. These results show that the current taxonomy of G. labiatus and G. lacustris does not properly represent evolutionary lineages in these species.(AU)

Gymnogeophagus labiatus e G. lacustris vêm sendo consideradas espécies irmãs que possuem diferentes exigências ecológicas. Gymnogeophagus labiatus ocorre em rios de fundo de pedra nas bacias hidrográficas da Laguna dos Patos (HBP) e do rio Tramandaí (HBT), enquanto G. lacustris é exclusivo da HBT, ocorrendo em lagoas costeiras de fundo de arenoso. Nesse estudo, foram usados marcadores moleculares, medidas morfológicas e dados sobre a coloração nupcial em machos para investigar a relação evolutiva entre estas espécies em cada bacia hidrográfica. Para todos os conjuntos de dados foi observada uma relação mais próxima entre G. labiatus e G. lacustris da HBT do que entre as populações de G. labiatus da HBP e HBT. Em particular, a área do lábio teve uma grande plasticidade intraespecífica, não sendo informativa para diagnosticar G. lacustris de G. labiatus. Estimativas baseadas no relógio molecular sugeriram uma divergência recente entre as espécies da HBT (17.000 anos atrás), mas não entre as populações de G. labiatus da HBP e HBT (3,6 milhões de anos atrás). Finalmente, também foi encontrada uma linhagem genética de G. labiatus divergente no rio Camaquã, na HBP. Esses resultados mostram que a taxonomia atual de G. labiatus e G. lacustris não representa adequadamente as linhagens evolutivas nessas espécies.(AU)

Crane flies (Diptera, Tipuloidea) from southern Neotropical salt marshes: survey with DNA barcoding

ABSTRACT Crane flies are the most diverse group within Diptera, but they are rarely studied in coastal ecosystems. Considering the scarcity of information on the biology and ecology of this group in the Neotropics, and the sparse literature available for taxonomic identification, we developed a descriptive checklist that incorporates morphology and DNA barcoding. We also created a generic identification key for crane flies of southern Brazilian salt marshes. We sampled crane flies continuously at three areas along the Patos Lagoon salt marshes over one year. A total of 14 genera/subgenera, 6 species, and 12 morphotypes belonging to Limoniidae and Tipulidae were identified. Distribution ranges of Symplecta cana (Walker, 1848) and two Ormosia Rondani, 1856 species were expanded. mtDNA COI sequences were compared to the BOLD and NCBI databases, but were matched only at the family level. Therefore, we provided sequences to both platforms, updated to the genus level. We found low (0.00-0.03) intraspecific and high (0.11-0.25) interspecific molecular differences indicating that the mtDNA COI region is adequate for distinguishing species within the Tipuloidea. The Dicranomyia Stephens, 1829 species complex showed low genetic difference, indicating that they could be one species with high morphological plasticity. This study will serve as a basis for future research on insects of Neotropical salt marshes.

Crane flies (Diptera, Tipuloidea) from southern Neotropical salt marshes: survey with DNA barcoding

Crane flies are the most diverse group within Diptera, but they are rarely studied in coastal ecosystems. Considering the scarcity of information on the biology and ecology of this group in the Neotropics, and the sparse literature available for taxonomic identification, we developed a descriptive checklist that incorporates morphology and DNA barcoding. We also created a generic identification key for crane flies of southern Brazilian salt marshes. We sampled crane flies continuously at three areas along the Patos Lagoon salt marshes over one year. A total of 14 genera/subgenera, 6 species, and 12 morphotypes belonging to Limoniidae and Tipulidae were identified. Distribution ranges of Symplecta cana (Walker, 1848) and two Ormosia Rondani, 1856 species were expanded. mtDNA COI sequences were compared to the BOLD and NCBI databases, but were matched only at the family level. Therefore, we provided sequences to both platforms, updated to the genus level. We found low (0.00-0.03) intraspecific and high (0.11-0.25) interspecific molecular differences indicating that the mtDNA COI region is adequate for distinguishing species within the Tipuloidea. The Dicranomyia Stephens, 1829 species complex showed low genetic difference, indicating that they could be one species with high morphological plasticity. This study will serve as a basis for future research on insects of Neotropical salt marshes.(AU)

Crane flies (Diptera, Tipuloidea) from southern Neotropical salt marshes: survey with DNA barcoding

Crane flies are the most diverse group within Diptera, but they are rarely studied in coastal ecosystems. Considering the scarcity of information on the biology and ecology of this group in the Neotropics, and the sparse literature available for taxonomic identification, we developed a descriptive checklist that incorporates morphology and DNA barcoding. We also created a generic identification key for crane flies of southern Brazilian salt marshes. We sampled crane flies continuously at three areas along the Patos Lagoon salt marshes over one year. A total of 14 genera/subgenera, 6 species, and 12 morphotypes belonging to Limoniidae and Tipulidae were identified. Distribution ranges of Symplecta cana (Walker, 1848) and two Ormosia Rondani, 1856 species were expanded. mtDNA COI sequences were compared to the BOLD and NCBI databases, but were matched only at the family level. Therefore, we provided sequences to both platforms, updated to the genus level. We found low (0.00-0.03) intraspecific and high (0.11-0.25) interspecific molecular differences indicating that the mtDNA COI region is adequate for distinguishing species within the Tipuloidea. The Dicranomyia Stephens, 1829 species complex showed low genetic difference, indicating that they could be one species with high morphological plasticity. This study will serve as a basis for future research on insects of Neotropical salt marshes.

Defining the reproductive period of freshwater fish species using the Gonadosomatic Index: a proposed protocol applied to ten species of the Patos Lagoon basin

This contribution records the reproductive periods of ten dominant freshwater fish species from the Patos Lagoon and Guaíba Lake (Astyanax fasciatus, Cyphocharax voga, Hoplias malabaricus, Oligosarcus jenynsii, Oligosarcus robustus, Hoplosternum littorale, Loricariichthys anus, Parapimelodus nigribarbis, Trachelyopterus lucenai, Pachyurus bonariensis). Data were derived from monthly samples in Casamento Lake (northern Patos Lagoon; Nov. 2002 to Apr. 2004) and Guaíba Lake (Jun. 2005 to May 2006). The reproductive period was determined according to the monthly variation of the gonadosomatic index (GSI). Fish reproduction was identified during all months of the year. Oligosarcus jenynsii started reproduction in winter, but extended spawning to spring (early warming-water reproduction). Three species also presented reproduction during warming water months, but beginning in spring and finishing in summer (late warm-water reproduction): P. nigribarbis, T. lucenai and P. bonariensis. Three species presented relatively short reproduction periods on summer (spotted warm-water reproduction): H. malabaricus, H. littorale and L. anus, and only one species reproduces almost continuously during warmer waters (long-season warm-water reproduction): A. fasciatus. Finally, two other species presented a very distinct reproductive pattern, starting reproduction on late summer but increasing GSI values along autumn and winter (long-season cooling-water reproducers): C. voga and O. robustus.(AU)

Esta pesquisa registra o período reprodutivo de dez espécies de peixes dulcícolas dominantes na região límnica da Laguna dos Patos e Lago Guaíba (Astyanax fasciatus, Cyphocharax voga, Hoplias malabaricus, Oligosarcus jenynsii, Oligosarcus robustus, Hoplosternum littorale, Loricariichthys anus, Parapimelodus nigribarbis, Trachelyopterus lucenai, Pachyurus bonariensis). Os dados derivam de amostras mensais realizadas na Lagoa do Casamento (Nordeste da Laguna dos Patos; Nov. 2002 a Abr. 2004) e no Lago Guaíba (Jun. 2005 a Maio 2006). A reprodução de peixes foi identificada durante todos os meses do ano. Oligosarcus jenynsii iniciou a reprodução no inverno, mas prolongou a desova até a primavera (reprodução no início do ciclo de aquecimento da água). Três espécies também apresentaram reprodução durante os meses de aquecimento da água, mas começando na primavera e terminando no verão (reprodução tardia do ciclo de aquecimento da água): P. nigribarbis, T. lucenai e P. bonariensis. Três espécies apresentaram períodos de reprodução relativamente curtos no verão (reprodução concentrada em período de água quente): H. malabaricus, H. littorale e L. anus, e apenas uma espécie se reproduz quase continuamente durante águas mais quentes (reprodução de longa duração em período de água quente): A. fasciatus. Finalmente, duas outras espécies apresentaram um padrão reprodutivo muito distinto, iniciando a reprodução no final do verão, mas aumentando os valores do IGS ao longo do outono e inverno (reprodutores de longo período com águas em resfriamento): C. voga e O. robustus.(AU)

Defining the reproductive period of freshwater fish species using the Gonadosomatic Index: a proposed protocol applied to ten species of the Patos Lagoon basin

This contribution records the reproductive periods of ten dominant freshwater fish species from the Patos Lagoon and Guaíba Lake (Astyanax fasciatus, Cyphocharax voga, Hoplias malabaricus, Oligosarcus jenynsii, Oligosarcus robustus, Hoplosternum littorale, Loricariichthys anus, Parapimelodus nigribarbis, Trachelyopterus lucenai, Pachyurus bonariensis). Data were derived from monthly samples in Casamento Lake (northern Patos Lagoon; Nov. 2002 to Apr. 2004) and Guaíba Lake (Jun. 2005 to May 2006). The reproductive period was determined according to the monthly variation of the gonadosomatic index (GSI). Fish reproduction was identified during all months of the year. Oligosarcus jenynsii started reproduction in winter, but extended spawning to spring (early warming-water reproduction). Three species also presented reproduction during warming water months, but beginning in spring and finishing in summer (late warm-water reproduction): P. nigribarbis, T. lucenai and P. bonariensis. Three species presented relatively short reproduction periods on summer (spotted warm-water reproduction): H. malabaricus, H. littorale and L. anus, and only one species reproduces almost continuously during warmer waters (long-season warm-water reproduction): A. fasciatus. Finally, two other species presented a very distinct reproductive pattern, starting reproduction on late summer but increasing GSI values along autumn and winter (long-season cooling-water reproducers): C. voga and O. robustus.(AU)

Esta pesquisa registra o período reprodutivo de dez espécies de peixes dulcícolas dominantes na região límnica da Laguna dos Patos e Lago Guaíba (Astyanax fasciatus, Cyphocharax voga, Hoplias malabaricus, Oligosarcus jenynsii, Oligosarcus robustus, Hoplosternum littorale, Loricariichthys anus, Parapimelodus nigribarbis, Trachelyopterus lucenai, Pachyurus bonariensis). Os dados derivam de amostras mensais realizadas na Lagoa do Casamento (Nordeste da Laguna dos Patos; Nov. 2002 a Abr. 2004) e no Lago Guaíba (Jun. 2005 a Maio 2006). A reprodução de peixes foi identificada durante todos os meses do ano. Oligosarcus jenynsii iniciou a reprodução no inverno, mas prolongou a desova até a primavera (reprodução no início do ciclo de aquecimento da água). Três espécies também apresentaram reprodução durante os meses de aquecimento da água, mas começando na primavera e terminando no verão (reprodução tardia do ciclo de aquecimento da água): P. nigribarbis, T. lucenai e P. bonariensis. Três espécies apresentaram períodos de reprodução relativamente curtos no verão (reprodução concentrada em período de água quente): H. malabaricus, H. littorale e L. anus, e apenas uma espécie se reproduz quase continuamente durante águas mais quentes (reprodução de longa duração em período de água quente): A. fasciatus. Finalmente, duas outras espécies apresentaram um padrão reprodutivo muito distinto, iniciando a reprodução no final do verão, mas aumentando os valores do IGS ao longo do outono e inverno (reprodutores de longo período com águas em resfriamento): C. voga e O. robustus.(AU)

Biology, distribution and geographic variation of loliginid squids (Mollusca: Cephalopoda) off southwestern Atlantic

The biology and ecology of southwestern Atlantic loliginid squids have been intensively researched in the last few decades, mostly off the Brazilian southern coast. However, information gathered by scientific research cruisers, either past or recent, is limited. Three species of loliginid squids - the warm-tempered Doryteuthis sanpaulensis(Brakoniecki, 1984), plus the tropical D. pleii (Blainville, 1823) and Lolliguncula brevis (Blainville, 1823) - were sampled along 16 degrees of latitude on the southwestern Atlantic (22-38°S). The samples were obtained mostly from oceanographic surveys, but also included squids caught by commercial fisheries, and a few specimens from museum collections. Squid response to abiotic variables, morphological variation and circadian behaviour were surveyed in detail. Doryteuthis sanpaulensis can be divided into at least six distinguishable geographical groups, which do not form a cline. In contrast, D. pleii can be divided into only two morphological groups that are very similar. Doryteuthis spp. were heterogeneously distributed on the shelf, whereas L. brevis was confined nearshore. Our data extended the southernmost distribution range of D. pleii by at least nine degrees of latitude, owing to specimens obtained at ~38°S (Mar del Plata, Argentina). Small, immature D. sanpaulensis were sampled inside the Patos Lagoon estuary (~32°S). The morphologically similar Doryteuthis spp. apparently avoid direct competition by concentrating at different depths, displaying different thermal preferences, and inverse circadian levels of activity. The information reported herein may be regarded as a “snapshot” of the ecology of sympatric squids in a marine environment that has not been deeply affected by climate change.

Biology, distribution and geographic variation of loliginid squids (Mollusca: Cephalopoda) off southwestern Atlantic

The biology and ecology of southwestern Atlantic loliginid squids have been intensively researched in the last few decades, mostly off the Brazilian southern coast. However, information gathered by scientific research cruisers, either past or recent, is limited. Three species of loliginid squids - the warm-tempered Doryteuthis sanpaulensis(Brakoniecki, 1984), plus the tropical D. pleii (Blainville, 1823) and Lolliguncula brevis (Blainville, 1823) - were sampled along 16 degrees of latitude on the southwestern Atlantic (22-38°S). The samples were obtained mostly from oceanographic surveys, but also included squids caught by commercial fisheries, and a few specimens from museum collections. Squid response to abiotic variables, morphological variation and circadian behaviour were surveyed in detail. Doryteuthis sanpaulensis can be divided into at least six distinguishable geographical groups, which do not form a cline. In contrast, D. pleii can be divided into only two morphological groups that are very similar. Doryteuthis spp. were heterogeneously distributed on the shelf, whereas L. brevis was confined nearshore. Our data extended the southernmost distribution range of D. pleii by at least nine degrees of latitude, owing to specimens obtained at ~38°S (Mar del Plata, Argentina). Small, immature D. sanpaulensis were sampled inside the Patos Lagoon estuary (~32°S). The morphologically similar Doryteuthis spp. apparently avoid direct competition by concentrating at different depths, displaying different thermal preferences, and inverse circadian levels of activity. The information reported herein may be regarded as a “snapshot” of the ecology of sympatric squids in a marine environment that has not been deeply affected by climate change.(AU)

The artisanal fishing of black drum (Pogonias cromis, Sciaenidae) in estuary Lagoon of Patos, Brazil / A pesca artesanal da miragaia (Pogonias cromis, Sciaenidae) no estuário da Lagoa dos Patos, Brasil

The increasing in the abundance of non-resident fish in the estuarine area attracts the interest of the fishing fleet, which determines the fishing seasons in the same period of increasing abundance. The black drum (Pogonias cromis) is an estuarine-dependent fish, (threatened with extinction due to) overexploitation in southern Brazil. In the estuary of Patos Lagoon, the scarcity of data on the biology and fishery species (hinder) the formulation of management plans. This study aims to analyze the artisanal fisheries of the black drum in the estuary of Patos Lagoon, by analyzing CPUE changes and the different compositions of juveniles, adults, males and females landed, relating them to the period of abundance increasing in the region. The fishing effort is the main cause for variations in the abundance of black drum in the estuary of Patos Lagoon, where the largest catches occur inside and outside the breeding season. The composition of landings varies throughout the year, females and adult fish predominate during the reproductive season, during the rest of the year no significant difference between males and females was found, and juveniles are predominant in the landings. The mean age of fish also changed, with higher values in spawning period. We conclude that these fisheries would prevent the recovery of the stock.(AU)

O aumento na abundância de peixes não residentes da zona estuarina atrai o interesse da frota pesqueira, o que determina o período das safras de pesca na mesma época do aumento da abundância. No sul do Brasil a miragaia (Pogonias cromis) é um peixe estuarino-dependente, ameaçado de extinção devido a sobreexplotação. No estuário da Lagoa dos Patos, a falta de dados sobre a biologia e pesca da espécie são fatores limitantes na formulação de planos de manejo. Este trabalho tem o objetivo de analisar a pesca artesanal da miragaia no estuário da Lagoa dos Patos, discutindo as variações da CPUE e as diferentes composições de juvenis e adultos desembarcados, relacionando-as com o período de aumento da abundância na região. A pesca intensa é o principal responsável pelas variações na abundância miragaias no estuário da Lagoa dos Patos, onde as altas capturas acontecem dentro e fora do período reprodutivo. A composição dos desembarques se modifica ao longo do ano, fêmeas e peixes adultos predominam na estação reprodutiva, durante o período de repouso não há diferença significativa entre machos e fêmeas, e juvenis são predominantes, a média de idade também se modifica, com maiores valores no período de desova. Conclui-se que esta pescaria pode comprometer a recuperação do estoque.(AU)

The artisanal fishing of black drum (Pogonias cromis, Sciaenidae) in estuary Lagoon of Patos, Brazil / A pesca artesanal da miragaia (Pogonias cromis, Sciaenidae) no estuário da Lagoa dos Patos, Brasil

The increasing in the abundance of non-resident fish in the estuarine area attracts the interest of the fishing fleet, which determines the fishing seasons in the same period of increasing abundance. The black drum (Pogonias cromis) is an estuarine-dependent fish, (threatened with extinction due to) overexploitation in southern Brazil. In the estuary of Patos Lagoon, the scarcity of data on the biology and fishery species (hinder) the formulation of management plans. This study aims to analyze the artisanal fisheries of the black drum in the estuary of Patos Lagoon, by analyzing CPUE changes and the different compositions of juveniles, adults, males and females landed, relating them to the period of abundance increasing in the region. The fishing effort is the main cause for variations in the abundance of black drum in the estuary of Patos Lagoon, where the largest catches occur inside and outside the breeding season. The composition of landings varies throughout the year, females and adult fish predominate during the reproductive season, during the rest of the year no significant difference between males and females was found, and juveniles are predominant in the landings. The mean age of fish also changed, with higher values in spawning period. We conclude that these fisheries would prevent the recovery of the stock.

O aumento na abundância de peixes não residentes da zona estuarina atrai o interesse da frota pesqueira, o que determina o período das safras de pesca na mesma época do aumento da abundância. No sul do Brasil a miragaia (Pogonias cromis) é um peixe estuarino-dependente, ameaçado de extinção devido a sobreexplotação. No estuário da Lagoa dos Patos, a falta de dados sobre a biologia e pesca da espécie são fatores limitantes na formulação de planos de manejo. Este trabalho tem o objetivo de analisar a pesca artesanal da miragaia no estuário da Lagoa dos Patos, discutindo as variações da CPUE e as diferentes composições de juvenis e adultos desembarcados, relacionando-as com o período de aumento da abundância na região. A pesca intensa é o principal responsável pelas variações na abundância miragaias no estuário da Lagoa dos Patos, onde as altas capturas acontecem dentro e fora do período reprodutivo. A composição dos desembarques se modifica ao longo do ano, fêmeas e peixes adultos predominam na estação reprodutiva, durante o período de repouso não há diferença significativa entre machos e fêmeas, e juvenis são predominantes, a média de idade também se modifica, com maiores valores no período de desova. Conclui-se que esta pescaria pode comprometer a recuperação do estoque.

Carbon primary sources and estuarine habitat use by two congeneric ariid catfishes in a subtropical coastal lagoon

Although ariid catfishe species are known to use coastal systems during some stages of their life cycles, the energetic contribution of estuarine resources and habitat use by many species in this family are still unclear. We used stable isotope analyses to estimate the assimilation of primary carbon sources and to infer the use of estuarine and freshwater habitats by two ariid catfishes Genidens barbus (Lacepède, 1803) and Genidens genidens (Cuvier, 1829). An isotopic mixing model revealed that juveniles of both catfish species consume considerable amounts of estuarine-produced carbon sources (G. barbus: 54-87% and G. genidens: 36-84%). However, G. genidens adults rely more on freshwater-derived carbon sources (31-77%) than on estuarine sources (23-69%). These results support the hypothesis that both species occupy the estuary and assimilate organic carbon produced in this region during their early stages, but G. genidens adults consume carbon sources associated with the freshwater portion of the lagoon.

Carbon primary sources and estuarine habitat use by two congeneric ariid catfishes in a subtropical coastal lagoon

Although ariid catfishe species are known to use coastal systems during some stages of their life cycles, the energetic contribution of estuarine resources and habitat use by many species in this family are still unclear. We used stable isotope analyses to estimate the assimilation of primary carbon sources and to infer the use of estuarine and freshwater habitats by two ariid catfishes Genidens barbus (Lacepède, 1803) and Genidens genidens (Cuvier, 1829). An isotopic mixing model revealed that juveniles of both catfish species consume considerable amounts of estuarine-produced carbon sources (G. barbus: 54-87% and G. genidens: 36-84%). However, G. genidens adults rely more on freshwater-derived carbon sources (31-77%) than on estuarine sources (23-69%). These results support the hypothesis that both species occupy the estuary and assimilate organic carbon produced in this region during their early stages, but G. genidens adults consume carbon sources associated with the freshwater portion of the lagoon.(AU)

Characterization of the variable region in the class 1 integron of antimicrobial-resistant Escherichia coli isolated from surface water

Fecal bacteria are considered to be a potential reservoir of antimicrobial resistance genes in the aquatic environment and could horizontally transfer these genes to autochthonous bacteria when carried on transferable and/or mobile genetic elements. Such circulation of resistance genes constitutes a latent public health hazard. The aim of this study was to characterize the variable region of the class 1 integron and relate its genetic content to resistance patterns observed in antimicrobial-resistant Escherichia coli isolated from the surface waters of Patos Lagoon, Southern Brazil. Genetic diversity of the isolates and presence of the qacE1 gene, which confers resistance to quaternary ammonium compounds, were also investigated. A total of 27 isolates were analyzed. The variable region harbored dfrA17, dfrA1 and dfrA12 genes, which confer resistance to trimethoprim, and aadA1, aadA5 and aadA22 genes that encode resistance to streptomycin/spectinomycin. Most of the isolates were considered resistant to quaternary ammonium compounds and all of them carried the qacE 1 gene at the 3 conserved segment of the integron. ERIC-PCR analyses of E. coli isolates that presented the integrons showed great genetic diversity, indicating diverse sources of contamination in this environment. These results suggest that fecal bacteria with class 1 integrons in aquatic environments are potentially important reservoirs of antibiotic-resistance genes and may transfer these elements to other bacteria that are capable of infecting humans.(AU)

Biodegradation of [D-Leu1] microcystin-LR by a bacterium isolated from sediment of Patos Lagoon estuary, Brazil

Background Toxic cyanobacterial blooms are recurrent in Patos Lagoon, in southern Brazil. Among cyanotoxins, [D-Leu1] microcystin-LR is the predominant variant whose natural cycle involves water and sediment compartments. This study aimed to identify and isolate from sediment a bacterial strain capable of growing on [D-Leu1] microcystin-LR. Sediment and water samples were collected at two distinct aquatic spots: close to the Oceanographic Museum (P1), in Rio Grande City, and on São Lourenço Beach (P2), in São Lourenço do Sul City, southern Brazil. Methods [D-Leu1] microcystin-LR was isolated and purified from batch cultures of Microcystis aeruginosastrain RST9501. Samples of water and sediment from Rio Grande and São Lourenço do Sul were collected. Bacteria from the samples were allowed to grow in flasks containing solely [D-Leu1] microcystin-LR. This strain named DMSX was isolated on agar MSM with 8 g L1 glucose and further purified on a cyanotoxin basis growth. Microcystin concentration was obtained by using the ELISA immunoassay for microcystins whereas bacterial count was performed by epifluorescence microscopy. The genus Pseudomonas was identified by DNA techniques. Results Although several bacterial strains were isolated from the samples, only one, DMXS, was capable of growing on [D-Leu1] microcystin-LR. The phylogenetic analysis of the 16S rRNA gene from DMXS strain classified the organism as Pseudomonas aeruginosa. DMXS strain incubated with [D-Leu1] microcystin-LR lowered the amount of toxin from 1 g.L1 to 0.05 g.L1. Besides, an increase in the bacterial countfrom 71×105 bacteria.mL1 to 117×105 bacteria.mL1was observed along the incubation. Conclusions The use of bacteria isolated from sediment for technological applications to remove toxic compounds is viable. Studies have shown that sediment plays an important role as a source of bacteria capable of degrading cyanobacterial toxins. This is the first Brazilian report on a bacteriumof the genus Pseudomonasthat can degrade [D-Leu1] microcystin-LR, the most frequent microcystin variant in Brazilian freshwaters.(AU)

Biodegradation of [D-Leu1] microcystin-LR by a bacterium isolated from sediment of Patos Lagoon estuary, Brazil

Background Toxic cyanobacterial blooms are recurrent in Patos Lagoon, in southern Brazil. Among cyanotoxins, [D-Leu1] microcystin-LR is the predominant variant whose natural cycle involves water and sediment compartments. This study aimed to identify and isolate from sediment a bacterial strain capable of growing on [D-Leu1] microcystin-LR. Sediment and water samples were collected at two distinct aquatic spots: close to the Oceanographic Museum (P1), in Rio Grande City, and on São Lourenço Beach (P2), in São Lourenço do Sul City, southern Brazil. Methods [D-Leu1] microcystin-LR was isolated and purified from batch cultures of Microcystis aeruginosastrain RST9501. Samples of water and sediment from Rio Grande and São Lourenço do Sul were collected. Bacteria from the samples were allowed to grow in flasks containing solely [D-Leu1] microcystin-LR. This strain named DMSX was isolated on agar MSM with 8 g L1 glucose and further purified on a cyanotoxin basis growth. Microcystin concentration was obtained by using the ELISA immunoassay for microcystins whereas bacterial count was performed by epifluorescence microscopy. The genus Pseudomonas was identified by DNA techniques. Results Although several bacterial strains were isolated from the samples, only one, DMXS, was capable of growing on [D-Leu1] microcystin-LR. The phylogenetic analysis of the 16S rRNA gene from DMXS strain classified the organism as Pseudomonas aeruginosa. DMXS strain incubated with [D-Leu1] microcystin-LR lowered the amount of toxin from 1 g.L1 to 0.05 g.L1. Besides, an increase in the bacterial countfrom 71×105 bacteria.mL1 to 117×105 bacteria.mL1was observed along the incubation. Conclusions The use of bacteria isolated from sediment for technological applications to remove toxic compounds is viable. Studies have shown that sediment plays an important role as a source of bacteria capable of degrading cyanobacterial toxins. This is the first Brazilian report on a bacteriumof the genus Pseudomonasthat can degrade [D-Leu1] microcystin-LR, the most frequent microcystin variant in Brazilian freshwaters.

Metazoan parasites of Geophagus brasiliensis (Perciformes: Cichlidae) in Patos lagoon, extreme south of Brazil / Metazoários parasitos de Geophagus brasiliensis (Perciformes: Cichlidae) da Lagoa dos Patos, extremo sul do Brasil

This study has evaluated the parasitic fauna of 79 pearl cichlids (Geophagus brasiliensis) from the estuary of Patos Lagoon (31° 57' S and 52° 06' W), Rio Grande do Sul, Brazil, during the months of May and June in 2011 and 2012. All the hosts analyzed were infected with at least one species of parasite. A total of eleven metazoa were identified in 459 specimens collected. The trematode Austrodiplostomum compactum (34.2%) and ergasilids Ergasilus lizae (32.9%) and Gauchergasilus lizae (32.9%) were the most prevalent species. The trematodes Thometrema overstreeti and Posthodiplostomum sp. had significantly higher prevalence in fish longer than 20 cm. The sex of the host had no effect on parasite prevalence and abundance. Pearl cichlids are registered as a new host for the trematodes Lobatostoma sp., Homalometron pseudopallidum and Thometrema overstreeti, for the ergasilids Ergasilus lizae and Gauchergasilus euripedesi and for the argulid Argulus spinolosus. The crustacean E. lizae is recorded in Rio Grande do Sul for the first time. (AU)

Este estudo avaliou a fauna parasitária de 79 Geophagus brasiliensis (acarás) proveniente do Estuário da Lagoa dos Patos (31°57S e 52°06W), Rio Grande do Sul, no período de Maio e Junho de 2011 a 2012. Todos os hospedeiros analisados estavam infectados com pelo menos uma espécie de parasito. Um total de onze metazoários foi identificado em 459 espécimes coletados. O trematoda Austrodiplostomum compactum (34,2%) e os ergasilídeos Ergasilus lizae (32,9%) e Gauchergasilus lizae (32,9%) foram às espécies mais prevalentes. Os trematodeos Thometrema overstreeti e Posthodiplostomum sp. apresentaram uma prevalência significativamente maior nos peixes acima de 20 cm. O gênero sexual dos hospedeiros não apresentou influência sobre a prevalência e a abundância parasitária. Geophagus brasiliensis é registrado como um novo hospedeiro para os trematódeos Lobatostoma sp., Homalometron pseudopallidum e Thometrema overstreeti, para os ergasilídeos Ergasilus lizae e Gauchergasilus euripedesi e para o argulídeo Argulus spinolosus. O crustáceo E. lizae é registrado pela primeira vez no Rio Grande do Sul. (AU)

Vibrio parahaemolyticus isolated from fishes captured from the Lagoa dos Patos estuary / Vibrio parahaemolyticus isolados de pescados do estuário da Lagoa dos Patos

Lagoa dos Patos estuary is an important artisanal fishing pole because it represents an area for breeding several species of fish and shellfish. Water is directly influenced by meteorological factors, which interfere in the ocean water into the estuary and flow, reflecting on the salinity. For this reason, there is the possibility of V. parahaemolyticus be found in the lagoon estuary; consequently the fish caught from these place could offer risks to the health of consumers. The objective of this study was to evaluate the presence of V. parahaemolyticus in the Lagoa dos Patos estuary, and in the fishes captured from small-scale fishing and processing. Fifty-six samples of fish caught from the Lagoa dos Patos estuary were analyzed for the presence of V. parahaemolyticus. Three of five species analyzed, shrimp (Farfantepenaeus paulensis), mullet (Mugil platanus) and sole (Paralichthys orbignyanus) harbored this microorganism. These results serve as a warning for providing the best technical oversight to the production of fish, and also the adoption of hygienic and sanitary measures to prevent the risk of transmission of this pathogen to consumers. This is the first report on the isolation of V. parahaemolyticus from F. paulensis, M. platanus and P.orbignyanus(AU)

O estuário da Lagoa dos Patos é um importante polo pesqueiro artesanal por constituir área de criação de diversas espécies de peixes e crustáceos. Suas águas são influenciadas diretamente por fatores meteorológicos, os quais interferem na entrada de água oceânica no estuário e na vazão, refletindo na sua salinidade. Por esta razão, há a possibilidade de V. parahaemolyticus ser encontrado no estuário da lagoa e, consequentemente, nos pescados nele capturados, o que ofereceria risco aos consumidores. O objetivo do estudo foi de avaliar a presença de V. parahaemolyticus em pescados do estuário da Lagoa dos Patos, capturados e processados artesanalmente. Cinquenta e seis amostras de pescados oriundos do estuário da Lagoa dos Patos foram analisadas quanto à presença de V. parahaemolyticus. Três das cinco espécies analisadas, camarão-rosa (Farfantepenaeus paulensis), tainha (Mugil platanus) e linguado (Paralichthys orbignyanus) albergavam o micro-organismo pesquisado. Estes resultados servem de alerta para a necessidade de maior fiscalização na produção de pescados, bem como da adoção de medidas higiênico-sanitárias que previnam o risco de transmissão deste patógeno para os consumidores. Este é o primeiro registro de isolamento de V. parahaemolyticus de F. paulensis, M. platanus e P. orbignyanus(AU)

Reproductive strategy of a non-annual rivulid in a perennial wetland / Estratégia reprodutiva de um rivulídeo não anual em um banhado perene

Atlantirivulus riograndensis (Costa & Lanés, 2009) is a fish registered to the basin of Patos lagoon and the adjacent coastal plains in southern states of Rio Grande do Sul and Santa Catarina, Brazil, found in shallow water courses with that have large quantities of aquatic vegetation and forest edges. The objective of this study was to investigate the reproductive strategy and tactics of this species including the sex ratio, the length at first maturity, spawning type, fecundity and the possible associations among reproduction and abiotic factors. Sampling of specimens occurred in perennial wetlands within the Banhado dos Pachecos wildlife refuge, in the city of Viamão, state of Rio Grande do Sul, Brazil, which is a conservation unit that belongs to an area of environmental protection in the Pampa Biome. The capture of 30 A. riograndensis specimens per month occurred from January to December of 2012. A total of 188 females and 172 males were captured and the total sex ratio was 1:1 in the sampled population. Sexual maturity of the species occurs after 13.59 and 11.92 mm (SL) for females and males, respectively. Both a multiple spawning and a long reproductive period (since August to March) were confirmed by the presence of post-ovulatory follicles that were observed through histological analysis and the values of the gonadosomatic index in females considered spawning capable. The average absolute fecundity of the species is of 19.33 (± 6.18) vitellogenic oocytes in mature ovaries. No significant relationship was found between mean GSI and the abiotic data. Reproductive tactics presented by A. riograndensis indicate a species with an opportunistic reproductive strategy, following the pattern of other species of the Rivulidae family.(AU)

Atlantirivulus riograndensis (Costa & Lanés, 2009) é uma espécie de peixe registrada para a bacia da laguna dos Patos e planícies costeiras adjacentes, nos estados do Rio Grande do Sul e sul de Santa Catarina, Brasil, encontrada em corpos d'água rasos, com grande quantidade de vegetação aquática e em bordas de mata. O objetivo deste estudo consistiu em investigar a estratégia e as táticas reprodutivas desta espécie, incluindo a proporção sexual, o comprimento de primeira maturação, o tipo de desova, a fecundidade e possíveis associações entre a reprodução e fatores abióticos. As amostragens de exemplares da espécie ocorreram em um banhado perene no Refúgio da Vida Silvestre Banhado dos Pachecos, município de Viamão, estado do Rio Grande do Sul, Brasil, que constitui uma área de proteção ambiental em uma unidade de conservação no bioma Pampa. A captura de trinta indivíduos de A. riograndensis por mês, ocorreu de janeiro a dezembro de 2012. Foram amostradas 188 fêmeas e 172 machos e a proporção sexual total foi de 1:1 na população amostrada. A maturação sexual da espécie ocorre a partir de 13,59 e 11,92 mm (CP) para fêmeas e machos, respectivamente. As análises histológicas demonstraram uma desova parcelada com a presença de folículos pós-ovulatórios em fêmeas consideradas aptas a desovar e um período reprodutivo longo, de agosto até março, confirmado pelos valores do índice gonadossomático. A fecundidade média absoluta da espécie foi de 19.33 (± 6.18) oócitos vitelogênicos em ovários maduros. Não houve relação significativa entre as médias de IGS e os dados abióticos. As táticas reprodutivas apresentadas por A. riograndensis indicam uma espécie com estratégia reprodutiva oportunista, seguindo o padrão das demais espécies da família Rivulidade.(AU)