New occurrences of the endangered Notholebias minimus (Cyprinodontiformes: Rivulidae) in coastal plains of the State of Rio de Janeiro, Brazil: populations features and conservation

Notholebias minimus is an endangered annual killifish endemic to the coastal plains of the State of Rio de Janeiro, Brazil. This study aimed to present new occurrences in the Atlantic Forest biome, provide unprecedented population features (body and egg size, fecundity, sexual ratio, and length-weight relationship - LWR), and compare changes in land use and coverage between 1985 and 2021 in biotopes located inside and outside protected areas. Three new occurrence localities were found in shallow temporary wetlands with acidic pH (6.4 ± 0.2) and low concentrations of dissolved oxygen (2.0 ± 0.9 mg/L). Males and females total length ranged from 11.1 to 31 mm and 11 to 26 mm, respectively. Batch fecundity ranged from 18 to 40 oocytes (24.8 ± 8.8), corresponding to oocytes with sizes between 800-1,006 µm (905 ± 56). Males were significantly larger than females (W = 2193.5, p = 0.0067), but both sexes occurred in similar proportions (p = 0.472). LWR showed positive allometry (b = 3.18). Biotopes located within protected areas exhibited higher conservation. Our discoveries expand the knowledge about habitat and population features of N. minimus and reinforce the importance of establishing protected areas for the conservation of annual fish biotopes.

Notholebias minimus é um peixe anual ameaçado de extinção, endêmico das planícies costeiras do Estado do Rio de Janeiro, Brasil. Neste estudo, objetivamos apresentar novas ocorrências no bioma Mata Atlântica, fornecer características populacionais inéditas (tamanho do corpo e dos ovos, fecundidade, proporção sexual e relação peso-comprimento), e comparar mudanças no uso e cobertura do solo entre 1985 e 2021 em biótopos localizados dentro e fora de unidades de conservação. Registramos três novos locais em áreas úmidas temporárias rasas com pH ácido (6,4 ± 0,2) e baixas concentrações de oxigênio dissolvido (2,0 ± 0,9 mg/L). O comprimento total de machos e fêmeas variou de 11,1 a 31 mm e de 11 a 26 mm, respectivamente. A fecundidade do lote variou entre 18-40 oócitos (24,8 ± 8,8), correspondendo a diâmetros entre 800-1.006 µm (905 ± 56). Os machos foram significativamente maiores que as fêmeas (W = 2193,5; p = 0,0067), mas ocorreram em proporções similares (p = 0,472). A relação peso-comprimento detectou alometria positiva (b = 3,18). Biótopos localizados dentro de áreas protegidas exibiram maior preservação ambiental. Nossas descobertas ampliam o conhecimento sobre as características do habitat e da população de N. minimus e reforçam a importância do estabelecimento de áreas protegidas para a conservação dos biótopos dos peixes anuais.

Genetic diversity of the species Cnesterodon hypselurus (Cyprinodontiformes: Poeciliidae) in Cinzas River basin: new record and headwater capture evidences

Cnesterodon hypselurus is a small fish that has a restricted distribution in southern Brazil, including headwaters of the Tibagi and Itararé river basins (Upper Paraná River). This study reported C. hypselurus in a headwater of Cinzas River basin, where there were no previous records of this species, and employed microsatellite loci and mitochondrial haplotypes in a population genetic analysis. A total of 57 specimens was analyzed, including 30 from Cinzas River basin, 25 from Itararé River basin and two from Tibagi River basin. Results indicated low genetic diversity levels (HE = 0.334 and h = 0.246) for the sample from Cinzas River, suggesting reflections of a founder effect after the species had dispersed from one watershed to another, possibly by headwater captures. Since different populations were detected between the Cinzas and Itararé rivers (DEST = 0.248, P-value < 0.05) and other occurrence sites are still unknown in the Cinzas River basin, the data herein have great relevance and should be taken into account in future management and conservation actions, as well as in evolutionary studies of C. hypselurus.(AU)

Cnesterodon hypselurus é um pequeno peixe que possui distribuição restrita no sul do Brasil, incluindo cabeceiras das bacias dos rios Tibagi e Itararé (alto rio Paraná). Este estudo reportou C. hypselurus na cabeceira da bacia do rio das Cinzas, onde não havia registros prévios desta espécie, e empregou locos microssatélites e haplótipos mitocondriais em uma análise genética de populações. Um total de 57 espécimes foi analisado, incluindo 30 do rio das Cinzas, 25 da bacia do rio Itararé e dois da bacia do rio Tibagi. Os resultados indicaram baixos níveis de diversidade genética (HE = 0,334 e h = 0,246) para a amostra do rio das Cinzas, sugerindo reflexos de um efeito fundador após a espécie ter dispersado de uma bacia para a outra, possivelmente a partir de captura de cabeceiras. Uma vez que diferentes populações foram detectadas entre os rios das Cinzas e Itararé (DEST = 0,248, valor de P < 0,05) e que outros pontos de ocorrência ainda são desconhecidos na bacia do rio das Cinzas, os dados do presente estudo mostram grande relevância e deveriam ser considerados em futuras ações de manejo e conservação, bem como em estudos evolutivos de C. hypselurus.(AU)

Influence of different types of margins in the fish assemblage from an urban river / Influência de diferentes tipos de margens na assembleia de peixes de um rio urbano

The presence or absence of a fish species may be associated with the physical and chemical characteristics of the water, in addition to the state of preservation of the riparian zone. This study examined whether the taxonomic fish composition in an urban river varies along three riparian zone preservation conditions: preserved, intermediate preservation and degraded. Six urban stretches of the Sorocaba/São Paulo River were selected for this study, with monthly sampling being carried out from June 2019 to February 2020. The samplings were carried out with the aid of a sieve, dip net, and trawl. Regarding the types of margins and environmental variables, the Principal Component Analysis explained 97.49% of the data variation, axis 1, which explained 91.85% of the total variation, was formed by the variables conductivity and total dissolved solids. Axis 2, which explained 5.64% of the variation, was formed by Sun Rays% and Siltation%, being inversely proportional to Riparian Forest%. For the ichthyofauna, the samples consisted in 50,983 fish distributed in 5 orders, 8 families, and 12 species. Cyprinodontiformes had the highest abundance, with 96.96% of the total number of individuals, followed by Siluriformes (2.39%), and the sum of the other orders did not reach 1% of the total collected. According to each type of margin, it was possible to register 11,592 individuals for the Margin A ­ preserved, with S=8 species, being 2 exclusive (Corydoras flaveolus and Hoplosternum littorale) and 3 exotic (Coptodon rendalli, Pterygoplichthys ambrosettii, and Poecilia reticulata), the latter was dominant in all types of margins. For Margin B ­ intermediate preservation, 19,645 individuals were sampled, with S=5 species, no exclusive species, only exotic and more tolerant native species such as Hoplias malabaricus and Hypostomus ancistroides. For Margin C ­ degraded, 19,746 individuals were recorded, the largest number of species (S=10), 3 were exclusive to this type of mar-gin (Psalidodon fasciatus, Rhamdia Quelen, and Geophagus brasiliensis). The pairwise comparison (similarity percentage) showed that the assemblage structure was different for the types of margins. The Canonical Cor-respondence Analysis explained 92.46% of the total data variation, showing the relationship of species to envi-ronmental data. It is evident the importance of preservation of micro-habitats still present in the locals sampled, since different anthropic pressures cause great loss of diversity, especially for native and more sensitive species.

A presença ou ausência de uma espécie de peixe que vive em rios urbanos pode estar associada às características físicas e químicas da água, além do estado de preservação da zona ripária. O presente estudo verificou se a composição taxonômica de peixes de um rio urbano varia em três condições de preservação da zona ripária: preservada, preservação intermediária e degradada. Seis trechos urbanos do rio Sorocaba, localizado no estado de São Paulo, foram selecionados para este estudo, com coletas mensais de junho de 2019 a fevereiro de 2020 com auxílio de peneira, puçá e rede de arrasto. Com relação aos tipos de margens e às variáveis ambientais, a análise de componentes principais explicou 97,49% da variação dos dados. O eixo 1, que explicou 91,85% da variação total, foi formado pelas variáveis condutividade e total de sólidos dissolvidos. O eixo 2, que explicou 5,64% da variação, foi formado pelo percentual das variáveis raios solares e assoreamento, revelando-se inversamente proporcional ao de mata ripária. Para a ictiofauna, foram amostrados 50.983 indivíduos compreendidos em cinco ordens, oito famílias e 12 espécies. Cyprinodontiformes apresentou maior abundância, com 96,96% do total de indivíduos, seguida de siluriformes (2,39%); a soma das demais ordens não atingiu 1% do total coletado. De acordo com cada tipo de margem, foi possível registrar 11.592 indivíduos para a margem A preservada, com a s=8 espécies, das quais duas foram exclusivas (C. flaveolus e H. littorale) e três exóticas (C. rendalli, P. ambrosettii e P. reticulata), sendo esta última dominante em todos os tipos de margens. Para a margem B intermediária, foram amostrados 19.645 indivíduos, com S=5 espécies, dos quais nenhum representante de espécie exclusiva, apenas espécies exóticas e nativas mais tolerantes, como H. malabaricus e H. ancistroides. Já para margem C degradada, foram registrados 19.746 exemplares, maior número de espécies (s=10), três delas exclusivas desse tipo de margem (P. fasciatus, R. quelen e G. brasiliensis). A comparação par a par (porcentagem similar) mostrou que a estrutura da assembleia se apresentou distinta para os tipos de margens. A análise de correspondência canônica explicou 92,46% da variação total dos dados, evidenciando a relação das espécies com os dados ambientais. Torna-se evidente a importância da preservação dos micro-habitatsainda presentes nas margens amostradas, visto que diferentes pressões antrópicas causam grande perda de diversidade, sobretudo para espécies nativas e espécies mais sensíveis a essas alterações.

A new species of the seasonal killifish genus Moema (Cyprinodontiformes: Rivulidae) from the Piraí watershed in the Southwest Amazon basin

Moema, a genus of the Rivulidae family, currently comprises 20 valid species. Most of these species inhabit temporary pools in the Amazon basin and only one species is found in the upper Paraguay basin. A new member of this genus from the upper Río Madeira drainage is here described. Males of the new species differ from all congeners by the combination of a color pattern consisting of oblique, sometimes chevron-like, irregular rows of red and light blue double-dots on body; dark yellowish to golden pectoral fins with no visible markings; and a stripe pattern on the ventral section of caudal fin with a very narrow black marginal line, intermittent or even absent. The existence of infrageneric species groups within Moema, the geographic distribution and taxonomic aspects of the species present in the Ríos Mamoré and Iténez/Guaporé rivers drainages, and the observation of intraspecific aggression between males and amphibious lifestyle in the new species are discussed.

Moema, un género de la familia Rivulidae, actualmente comprende 20 especies válidas. La mayoría de estas especies habitan en charcos temporales de la cuenca amazónica y solo una especie se encuentra en la cuenca alta del Río Paraguay. Un nuevo miembro de este género de la cuenca alta del Río Madeira es descrito aquí. Los machos de la especie nueva se diferencian de todos los congéneres por la combinación de un patrón de color de filas irregulares oblicuas, a veces en forma de chevrón, de puntos dobles rojos y azul claro en el cuerpo; aletas pectorales de color amarillento oscuro a dorado sin marcas visibles; y un patrón de rayas en la sección ventral de la aleta caudal con una línea marginal negra muy estrecha, intermitente o incluso ausente. Se discute la existencia de grupos infragenéricos de especies dentro de Moema, la distribución geográfica y aspectos taxonómicos de las especies presentes en el drenaje de los Ríos Mamoré e Iténez/Guaporé, y la observación de agresión intraespecífica entre machos y estilo de vida anfibio en la nueva especie.

Reproductive cycle of native viviparous fish species (Actinopterygii: Cyprinodontiformes: Goodeidae) in a subtropical Mexican lake

Reproductive tactics and strategies contribute to the persistence and maintenance of long-term populations in fish species. Members of the subfamily Goodeinae are a group of small-bodied freshwater fish with specialized reproduction (viviparity-matrotrophy). They are found in the highlands of central Mexico, most of them endemic. The aim of this study was to conduct a comprehensive investigation to evaluate the annual reproductive cycle of seven species of goodeines (splitfins). We carried out our study in the subtropical Lake Zacapu, Mexico, with bi-monthly sampling from May 2019 to March 2020. We obtain the fertility, size at first maturity (L50), sex ratio, and gonadosomatic index. Our result shows that populations of goodeines have high fertility compared to other populations of the same species in other aquatic systems and also to other species of goodein. We found that males mature at smaller sizes than females, the observed proportion of females was greater than males in all the goodeines. Lake Zacapu goodeines have two reproductive peaks, one in spring (April to June) and another in fall (September to November). These tactics (fertility rates, sex ratio, reproductive period) and strategies (viviparity-matrotrophy) favor reproductive success in this environmentally stable subtropical lake in the highlands of Mexico.(AU)

Las tácticas y estrategias reproductivas contribuyen a la persistencia y el mantenimiento de las poblaciones a largo plazo en especies de peces. Miembros de la subfamilia Goodeinae son un grupo de peces de agua dulce con reproducción especializada (viviparidad-matrotrofia). Se encuentran en el centro de México, la mayoría de ellos endémicos. El objetivo de este estudio fue realizar una investigación integral para evaluar el ciclo reproductivo anual de siete especies de goodeines o mexclapiques. Realizamos nuestro estudio en el lago subtropical de Zacapu, México, con muestreo bimestral de mayo de 2019 a marzo de 2020. Nuestros resultados muestran que las poblaciones de goodeines tienen una alta fertilidad en comparación con otras poblaciones de la misma especie en otros sistemas acuáticos y también con otras especies de goodeines. Encontramos que los machos maduran en tamaños más pequeños que las hembras, la proporción observada de hembras fue mayor que los machos en todas las goodeines. Los goodeines del lago Zacapu tienen dos picos reproductivos, uno en primavera (abril a junio) y otro en otoño (septiembre a noviembre). Estas tácticas (fertilidad, proporción de sexos, período reproductivo) y estrategias (viviparidad-matrotrofia) favorecen el éxito reproductivo en este lago subtropical ambientalmente estable en el altiplano de México.(AU)

Reproductive cycle of native viviparous fish species (Actinopterygii: Cyprinodontiformes: Goodeidae) in a subtropical Mexican lake

Reproductive tactics and strategies contribute to the persistence and maintenance of long-term populations in fish species. Members of the subfamily Goodeinae are a group of small-bodied freshwater fish with specialized reproduction (viviparity-matrotrophy). They are found in the highlands of central Mexico, most of them endemic. The aim of this study was to conduct a comprehensive investigation to evaluate the annual reproductive cycle of seven species of goodeines (splitfins). We carried out our study in the subtropical Lake Zacapu, Mexico, with bi-monthly sampling from May 2019 to March 2020. We obtain the fertility, size at first maturity (L50), sex ratio, and gonadosomatic index. Our result shows that populations of goodeines have high fertility compared to other populations of the same species in other aquatic systems and also to other species of goodein. We found that males mature at smaller sizes than females, the observed proportion of females was greater than males in all the goodeines. Lake Zacapu goodeines have two reproductive peaks, one in spring (April to June) and another in fall (September to November). These tactics (fertility rates, sex ratio, reproductive period) and strategies (viviparity-matrotrophy) favor reproductive success in this environmentally stable subtropical lake in the highlands of Mexico.(AU)

Las tácticas y estrategias reproductivas contribuyen a la persistencia y el mantenimiento de las poblaciones a largo plazo en especies de peces. Miembros de la subfamilia Goodeinae son un grupo de peces de agua dulce con reproducción especializada (viviparidad-matrotrofia). Se encuentran en el centro de México, la mayoría de ellos endémicos. El objetivo de este estudio fue realizar una investigación integral para evaluar el ciclo reproductivo anual de siete especies de goodeines o mexclapiques. Realizamos nuestro estudio en el lago subtropical de Zacapu, México, con muestreo bimestral de mayo de 2019 a marzo de 2020. Nuestros resultados muestran que las poblaciones de goodeines tienen una alta fertilidad en comparación con otras poblaciones de la misma especie en otros sistemas acuáticos y también con otras especies de goodeines. Encontramos que los machos maduran en tamaños más pequeños que las hembras, la proporción observada de hembras fue mayor que los machos en todas las goodeines. Los goodeines del lago Zacapu tienen dos picos reproductivos, uno en primavera (abril a junio) y otro en otoño (septiembre a noviembre). Estas tácticas (fertilidad, proporción de sexos, período reproductivo) y estrategias (viviparidad-matrotrofia) favorecen el éxito reproductivo en este lago subtropical ambientalmente estable en el altiplano de México.(AU)

Plasma energetic substrates and hepatic enzymes in the four-eyed fish Anableps anableps (Teleostei: Cyprinodontiformes) during the dry and rainy seasons in the Amazonian Island of Maracá, extreme north of Brazil

ABSTRACT Anableps anableps is a viviparous teleost typical from Amazon Delta estuaries. It is representative of this biome in Maracá, which offers a potential for biomonitoring. The aim of this study is to apply different biomarkers to males and females of this species and verify possible seasonal influences on their physiology. To collect fish, three expeditions were carried out from the rainy season of April 2018 to the rainy season of February 2019. Biometric parameters and gonadosomatic (GSI), hepatosomatic (HSI), and viscerosomatic (VSI) indexes were calculated, and blood samples were taken to measure triglycerides, total proteins, glucose, and activity of the enzymes aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP). The GSI of males is higher in the rainy season and of females in the dry season. This is probably related to the embryogenesis process. Males show an increase in biomass during the dry season, a metabolic homogeneity, and females show an increase in plasma glucose, triglycerides, and ALT activity. The tested biomarkers are potential for biomonitoring, preliminarily suggesting that there is a seasonal asynchronism between males and females of A. anableps as for the allocation of energy resources at different times of their life cycle.

RESUMO Anableps anableps é um teleósteo vivíparo típico de estuários do Delta do Rio Amazonas, sendo representativo deste bioma na ilha de Maracá, com potencial para o biomonitoramento. O objetivo deste estudo foi aplicar diferentes biomarcadores em machos e fêmeas desta espécie e verificar a possível influência sazonal em aspectos de sua fisiologia. Para a coleta dos peixes foram realizadas três expedições, de abril/2018 (estação chuvosa), setembro/2018 (estação seca) até fevereiro/2019 (estação chuvosa). Foram obtidos parâmetros biométricos, índices gonadossomático (IGS), hepatossomático (IHS), viscerossomático (IVS) e amostras de sangue para dosagem de triglicerídeos, proteínas totais, glicose e a atividade das enzimas aspartato aminotransferase (AST), alanina aminotransferase (ALT) e fosfatase alcalina (ALP). O IGS dos machos foi maior na estação chuvosa e das fêmeas na estação seca, isso provavelmente ocorreu devido ao processo de embriogênese. Os machos aumentaram a biomassa na estação seca e apresentaram homogeneidade metabólica, já as fêmeas apresentaram hiperglicemia, hipertrigliceridemia e maior atividade da ALT. Os biomarcadores testados mostraram-se promissores para o biomonitoramento, sugerindo de forma preliminar que há um assincronismo sazonal entre machos e fêmeas de A. anableps na alocação de recursos energéticos em diferentes momentos do seu ciclo de vida.

Salinity and prey concentration on larviculture of killifish Hypsolebias radiseriatus (Cyprinodontiformes: Rivulidae)

The aim of this study was to investigate the tolerance of Hypsolebias radiseriatuslarvae to different salinities, and the effects of different prey concentrations and water salinities on the larviculture of this species. Salinity tolerance was tested by subjecting newly-hatched larvae to 96 hours of osmotic shock testing (experiment I) and gradual acclimatization (experiment II) of the following salinities: freshwater (control), 2, 4, 6 and 8 g of salt L-1. A third experiment (experiment III) evaluated three water salinities (S0-freshwater, S2-2 g of salt L-1and S4–4 g of salt L-1) and three initial daily prey concentrations (100, 300 and 500 artemia nauplii larva-1). In experiments I and II, survival was only influenced by the salinity of 8 g of salt L-1(p < 0.01). After 35 days, weight was only influenced by prey concentration (p < 0.05), with the highest value being with 500 artemia nauplii larva-1. The lowest survival was for 4 g of salt L-1and for 100 artemia nauplii larva-1. H. radiseriatuslarviculture can be carried out in salinity of up to 2 g of salt L-1and initial daily prey concentrations with 500 artemia nauplii larva-1.(AU)

Salinity and prey concentration on larviculture of killifish Hypsolebias radiseriatus (Cyprinodontiformes: Rivulidae)

The aim of this study was to investigate the tolerance of Hypsolebias radiseriatuslarvae to different salinities, and the effects of different prey concentrations and water salinities on the larviculture of this species. Salinity tolerance was tested by subjecting newly-hatched larvae to 96 hours of osmotic shock testing (experiment I) and gradual acclimatization (experiment II) of the following salinities: freshwater (control), 2, 4, 6 and 8 g of salt L-1. A third experiment (experiment III) evaluated three water salinities (S0-freshwater, S2-2 g of salt L-1and S4–4 g of salt L-1) and three initial daily prey concentrations (100, 300 and 500 artemia nauplii larva-1). In experiments I and II, survival was only influenced by the salinity of 8 g of salt L-1(p < 0.01). After 35 days, weight was only influenced by prey concentration (p < 0.05), with the highest value being with 500 artemia nauplii larva-1. The lowest survival was for 4 g of salt L-1and for 100 artemia nauplii larva-1. H. radiseriatuslarviculture can be carried out in salinity of up to 2 g of salt L-1and initial daily prey concentrations with 500 artemia nauplii larva-1.

Length-weight relationships and biological aspects for 34 fish species from Três Irmãos reservoir, Lower Tietê River Basin, SP - Brazil / Relação comprimento-peso e aspectos biológicos de 34 espécies de peixes do reservatório de Três Irmãos, Bacia do Baixo Rio Tietê, SP - Brasil

The length-weight relationship of fish species is widely used in fisheries monitoring programs and it is an important tool for proposing stock management measures. The objective of this study was to estimate the growth parameters of 34 species belonging to the fish community captured by experimental fishery in the Três Irmãos reservoir, Tietê river. The biological and ecological characteristics of these species are also presented in order to understand the profile of the present fish community. The fish were collected during ten experimental fishing seasons between October/2015 and February/2018, with quarterly frequency using four types of fishing gear. All fish captured were identified and the total length - TL (cm), standard length - SL (cm) and total weight - TW (g) were measured. The length-weight relationship was established using the linear regression TW vs SL (log-transformed): log (TW) = log (a) + b log (SL), where a is the regression curve intercept (coefficient related to body shape) and b is the coefficient of regression (exponent indicating the type of growth). A total of 7,319 individuals was identified, comprising five orders: Characiformes (7 Families), Siluriformes (5 Families), Perciformes (1 Family), Cichliformes (1 Family) and Cyprinodontiformes (1 Family). The most abundant species were Plagioscion squamosissimus (N=1,513), Geophagus sveni (N=1,160), Serrasalmus maculatus (N=1,049) and Metynnis maculatus (pacu-CD) (N=974), all of them being target species for professional artisanal fishing, with the exception of pacu-CD, which is discarded since it has no commercial interest. From the whole set of analyzes 15 species (44.1%) have positive allometric growth type (3.15≤ b ≤3.59), 14 (41.2%) isometric (2.98≤ b ≤ 3.08), and 5 (14.7%) negative allometric growth (2.7 ≤ b ≤ 2.90)...

A relação comprimento-peso das espécies de peixes é bastante utilizada entre os cientistas em programas de monitoramento da pesca, sendo uma ferramenta importante na proposição de medidas de manejo dos estoques. Objetiva-se estimar os parâmetros de crescimento de 34 espécies pertencentes à comunidade de peixes capturada pela pesca experimental no reservatório de Três Irmãos, rio Tietê. As características biológicas e ecológicas das espécies são também apresentadas visando a elaboração do perfil da comunidade. Os peixes foram coletados durante dez campanhas da pesca experimental, entre outubro/2015 a fevereiro/2018, com periodicidade trimestral, usando quatro tipos de aparelhos de pesca. Todos os peixes capturados foram identificados, mensurados em termos de comprimento total – Ct (cm) e comprimento padrão - Cp (cm), e obtido o peso total – Pt (g). A relação foi estabelecida usando a regressão linear Pt vs Cp (log-transformada): log (Pt) = log (a) + b log (Cp), onde a é o intercepto da curva de regressão (coeficiente relacionado à forma do corpo) e b o coeficiente de regressão (expoente indicando o tipo de crescimento). Foram identificados 7.319 indivíduos, compostos por cinco Ordens: Characiformes (7 Famílias), Siluriformes (5 Famílias), Perciformes (1 Família), Cichliformes (1 Família) e Cyprinodontiformes (1 Família). As espécies mais abundantes foram Plagioscion squamosissimus(corvina) (N= 1.513), Geophagus sveni (porquinho) (N=1.160), Serrasalmus maculatus (piranha/pirambeba) (N=1.049) e Metynnis maculatus (pacu-CD) (N=974), espécies alvo da pesca artesanal profissional; com exceção do pacu-CD que é descartado por não ter interesse comercial. Do conjunto analisado, 15 espécies (44.1%) possuem crescimento do tipo alométrico positivo (3,13 ≤ b ≤3,62), 14 (41.2%) isométrico (2,91 ≤ b ≤ 3,08), e 5 (14.7%) alométrico negativo (2,71 ≤ b ≤ 2,94)...

Length-weight relationships and biological aspects for 34 fish species from Três Irmãos reservoir, Lower Tietê River Basin, SP - Brazil / Relação comprimento-peso e aspectos biológicos de 34 espécies de peixes do reservatório de Três Irmãos, Bacia do Baixo Rio Tietê, SP - Brasil

The length-weight relationship of fish species is widely used in fisheries monitoring programs and it is an important tool for proposing stock management measures. The objective of this study was to estimate the growth parameters of 34 species belonging to the fish community captured by experimental fishery in the Três Irmãos reservoir, Tietê river. The biological and ecological characteristics of these species are also presented in order to understand the profile of the present fish community. The fish were collected during ten experimental fishing seasons between October/2015 and February/2018, with quarterly frequency using four types of fishing gear. All fish captured were identified and the total length - TL (cm), standard length - SL (cm) and total weight - TW (g) were measured. The length-weight relationship was established using the linear regression TW vs SL (log-transformed): log (TW) = log (a) + b log (SL), where a is the regression curve intercept (coefficient related to body shape) and b is the coefficient of regression (exponent indicating the type of growth). A total of 7,319 individuals was identified, comprising five orders: Characiformes (7 Families), Siluriformes (5 Families), Perciformes (1 Family), Cichliformes (1 Family) and Cyprinodontiformes (1 Family). The most abundant species were Plagioscion squamosissimus (N=1,513), Geophagus sveni (N=1,160), Serrasalmus maculatus (N=1,049) and Metynnis maculatus (pacu-CD) (N=974), all of them being target species for professional artisanal fishing, with the exception of pacu-CD, which is discarded since it has no commercial interest. From the whole set of analyzes 15 species (44.1%) have positive allometric growth type (3.15≤ b ≤3.59), 14 (41.2%) isometric (2.98≤ b ≤ 3.08), and 5 (14.7%) negative allometric growth (2.7 ≤ b ≤ 2.90)...(AU)

A relação comprimento-peso das espécies de peixes é bastante utilizada entre os cientistas em programas de monitoramento da pesca, sendo uma ferramenta importante na proposição de medidas de manejo dos estoques. Objetiva-se estimar os parâmetros de crescimento de 34 espécies pertencentes à comunidade de peixes capturada pela pesca experimental no reservatório de Três Irmãos, rio Tietê. As características biológicas e ecológicas das espécies são também apresentadas visando a elaboração do perfil da comunidade. Os peixes foram coletados durante dez campanhas da pesca experimental, entre outubro/2015 a fevereiro/2018, com periodicidade trimestral, usando quatro tipos de aparelhos de pesca. Todos os peixes capturados foram identificados, mensurados em termos de comprimento total Ct (cm) e comprimento padrão - Cp (cm), e obtido o peso total Pt (g). A relação foi estabelecida usando a regressão linear Pt vs Cp (log-transformada): log (Pt) = log (a) + b log (Cp), onde a é o intercepto da curva de regressão (coeficiente relacionado à forma do corpo) e b o coeficiente de regressão (expoente indicando o tipo de crescimento). Foram identificados 7.319 indivíduos, compostos por cinco Ordens: Characiformes (7 Famílias), Siluriformes (5 Famílias), Perciformes (1 Família), Cichliformes (1 Família) e Cyprinodontiformes (1 Família). As espécies mais abundantes foram Plagioscion squamosissimus(corvina) (N= 1.513), Geophagus sveni (porquinho) (N=1.160), Serrasalmus maculatus (piranha/pirambeba) (N=1.049) e Metynnis maculatus (pacu-CD) (N=974), espécies alvo da pesca artesanal profissional; com exceção do pacu-CD que é descartado por não ter interesse comercial. Do conjunto analisado, 15 espécies (44.1%) possuem crescimento do tipo alométrico positivo (3,13 ≤ b ≤3,62), 14 (41.2%) isométrico (2,91 ≤ b ≤ 3,08), e 5 (14.7%) alométrico negativo (2,71 ≤ b ≤ 2,94)...(AU)

Review of the family Rivulidae (Cyprinodontiformes, Aplocheiloidei) and a molecular and morphological phylogeny of the annual fish genus Austrolebias Costa 1998

The family Rivulidae is the fourth most diverse clade of Neotropical fishes. Together with some genera of the related African family Nothobranchiidae, many rivulids exhibit a characteristic annual life cycle, with diapausing eggs and delayed embryonic development, which allows them to survive in the challenging seasonal ponds that they inhabit. Rivulidae also includes two species known as the only the self-fertilizing vertebrates and some species with internal fertilization. The first goal of this article is to review the systematics of the family considering phylogenetic relationships and synapomorphies of subfamilial clades, thus unifying information that is dispersed throughout the literature. From this revision, it is clear that phylogenetic relationships within Rivulidae are poorly resolved, especially in one of the large clades that compose it, the subfamily Rivulinae, where conflicting hypotheses of relationships of non-annual and annual genera are evident. The second goal of this work is to present an updated phylogenetic hypothesis (based on mitochondrial, nuclear, and morphological information) for one of the most speciose genus of Rivulidae, Austrolebias. Our results confirm the monophyly of the genus and of some subgeneric clades already diagnosed, but propose new relationships among them and their species composition, particularly in the subgenus Acrolebias.

a familia Rivulidae es el cuarto clado más diverso dentro de los peces Neotropicales. Junto con algunos géneros de la familia Nothobranchiidae, muchos rivulidos presentan un característico ciclo de vida anual, con huevos resistentes a la desecación y embriones con diapausas que les permiten sobrevivir en los ambientes estacionales donde habitan. Los Rivulidae presentan también dos especies consideradas como los únicos vertebrados hermafroditas suficientes y algunas especies con inseminación interna. El primer objetivo de este artículo es actualizar la sistemática de la familia considerando las relaciones filogenéticas y las sinapomorfías de los clados que la componen, reuniendo información que se encuentra dispersa en la literatura. De esta revisión surge que las relaciones filogenéticas dentro de Rivulidae están todavía sin resolver, especialmente en uno de los grandes clados que la componen, la subfamilia Rivulinae, donde relaciones conflictivas entre géneros anuales y no anuales son evidentes. El segundo objetivo de este trabajo es presentar una hipótesis filogenética, basada en datos morfológicos, mitocondriales y nucleares, de uno de los géneros más diversos de la familia, el género Austrolebias. Nuestros resultados confirman la monofilia del género y de algunos clados subgenéricos previamente definidos, y propone nuevas relaciones entre ellos, particularmente de las especies del subgénero Acrolebias(AU)

Review of the family Rivulidae (Cyprinodontiformes, Aplocheiloidei) and a molecular and morphological phylogeny of the annual fish genus Austrolebias Costa 1998

The family Rivulidae is the fourth most diverse clade of Neotropical fishes. Together with some genera of the related African family Nothobranchiidae, many rivulids exhibit a characteristic annual life cycle, with diapausing eggs and delayed embryonic development, which allows them to survive in the challenging seasonal ponds that they inhabit. Rivulidae also includes two species known as the only the self-fertilizing vertebrates and some species with internal fertilization. The first goal of this article is to review the systematics of the family considering phylogenetic relationships and synapomorphies of subfamilial clades, thus unifying information that is dispersed throughout the literature. From this revision, it is clear that phylogenetic relationships within Rivulidae are poorly resolved, especially in one of the large clades that compose it, the subfamily Rivulinae, where conflicting hypotheses of relationships of non-annual and annual genera are evident. The second goal of this work is to present an updated phylogenetic hypothesis (based on mitochondrial, nuclear, and morphological information) for one of the most speciose genus of Rivulidae, Austrolebias. Our results confirm the monophyly of the genus and of some subgeneric clades already diagnosed, but propose new relationships among them and their species composition, particularly in the subgenus Acrolebias.(AU)

La familia Rivulidae es el cuarto clado más diverso dentro de los peces Neotropicales. Junto con algunos géneros de la familia Nothobranchiidae, muchos rivulidos presentan un característico ciclo de vida anual, con huevos resistentes a la desecación y embriones con diapausas que les permiten sobrevivir en los ambientes estacionales donde habitan. Los Rivulidae presentan también dos especies consideradas como los únicos vertebrados hermafroditas suficientes y algunas especies con inseminación interna. El primer objetivo de este artículo es actualizar la sistemática de la familia considerando las relaciones filogenéticas y las sinapomorfías de los clados que la componen, reuniendo información que se encuentra dispersa en la literatura. De esta revisión surge que las relaciones filogenéticas dentro de Rivulidae están todavía sin resolver, especialmente en uno de los grandes clados que la componen, la subfamilia Rivulinae, donde relaciones conflictivas entre géneros anuales y no anuales son evidentes. El segundo objetivo de este trabajo es presentar una hipótesis filogenética, basada en datos morfológicos, mitocondriales y nucleares, de uno de los géneros más diversos de la familia, el género Austrolebias. Nuestros resultados confirman la monofilia del género y de algunos clados subgenéricos previamente definidos, y propone nuevas relaciones entre ellos, particularmente de las especies del subgénero Acrolebias.(AU)

Occasional release of guppy, Poecilia reticulata (Cyprinodontiformes, Poeciliidae) in Upper Paraguay River Basin, Mato Grosso State: a new threat to rivers forming the Brazilian Pantanal?

The guppy, Poecilia reticulata Peters, 1859 is an ovoviviparous freshwater fish of low waters native to the Caribbean Islands, Venezuela, Guyana, and northern Brazil (Amapá and Pará States) (Reis et al., 2013). Guppies are among the most popular fishes in the aquarium trade (Magalhães and Jacobi, 2013), and they are introduced into water bodies in many parts of Brazil through the aquarium dumping (Oliveira et al., 2014). This paper reports the first record of non-native P. reticulata in water bodies at midwest Brazil. Poecilia reticulata (Figures 1-4) was collected in nascent of stream Figueira (14º3898” S and 57º2954” W) located to eastern of Tangará da Serra, southwest region of Mato Grosso State. Samples were made at November 2015 using trawl (0.1 mm mesh) and sieve (2.0 mm mesh) in shallow waters during the day (two persons during 5 minutes), catching 350 specimens of guppy (148 females, 129 males and 73 juveniles). Fishes were euthanized (Borski and Hodson, 2003), fixed in 10% formalin and later stored in 70% ethanol. Voucher material is deposited in the fish collection of the ‘Museu de História Natural Capão da Imbuia, Curitiba, State of Paraná, Brazil (MHNCI).(AU)

Metaplasia in swim bladder epithelium of the endangered annual fish Austrolebias nigrofasciatus (Cyprinodontiformes: Rivulidae) results in inadequate swimming and delayed growth

Laboratory breeding of annual fish is often impaired when fish fail to inflate the swim bladder after hatching. These fish, which are known as belly-sliders, cannot swim in the water column, moving mainly on the bottom of water. Therefore, we wanted to understand the factors underlying failed inflation of swim bladder in the annual fish Austrolebias nigrofasciatus and determine the implications of this condition on the growth of juveniles. To identify how the initial filling of the gaseous vesicle is compromised, and to determine the implications of this condition on juvenile growth, we analysed the histology of the swim bladder of both normal swimming fish and belly-sliders during their initial growth phase (first month of life). In addition to slower growth rate compared with fish swimming normally, we found that belly-sliders have metaplasia characterized by epithelium peeling of the swim bladder and the presence of haemorrhage. Based on our findings, it can be concluded that metaplasia of the swim bladder is recurrent in annual fish bred in the laboratory, which explains the large number of unviable larvae. However, its causes remain unknown.(AU)

A criação de peixes anuais é frequentemente comprometida pela ocorrência de peixes que não inflam a vesícula gasosa após a eclosão. Estes peixes não têm capacidade de se manter e nadar na coluna d'água e se locomovem no fundo da água, por isso são chamados belly-sliders. Portanto, objetivamos entender os fatores subjacentes à inflação falhada da bexiga natatória no peixe anual Austrolebias nigrofasciatus e determinar as implicações dessa condição no crescimento de juvenis. Para identificar de que forma o enchimento inicial da vesícula gasosa é comprometido, e determinar as implicações desta condição no crescimento dos juvenis, analisamos histologicamente a vesícula gasosa de peixes com natação normal e de belly-sliders durante o crescimento inicial (primeiro mês de vida). Verificamos que os belly-sliders apresentam metaplasia com descamação do epitélio da vesícula gasosa e presença de hemorragia, além de apresentar crescimento mais lento em relação aos peixes com natação normal. Concluímos que a incidência desta patologia é um problema recorrente e de grande relevância para a manutenção de peixes anuais em laboratório, sendo responsável por uma grande quantidade de juvenis inviáveis, no entanto suas causas permanecem desconhecidas.(AU)

Metaplasia in swim bladder epithelium of the endangered annual fish Austrolebias nigrofasciatus (Cyprinodontiformes: Rivulidae) results in inadequate swimming and delayed growth

Laboratory breeding of annual fish is often impaired when fish fail to inflate the swim bladder after hatching. These fish, which are known as belly-sliders, cannot swim in the water column, moving mainly on the bottom of water. Therefore, we wanted to understand the factors underlying failed inflation of swim bladder in the annual fish Austrolebias nigrofasciatus and determine the implications of this condition on the growth of juveniles. To identify how the initial filling of the gaseous vesicle is compromised, and to determine the implications of this condition on juvenile growth, we analysed the histology of the swim bladder of both normal swimming fish and belly-sliders during their initial growth phase (first month of life). In addition to slower growth rate compared with fish swimming normally, we found that belly-sliders have metaplasia characterized by epithelium peeling of the swim bladder and the presence of haemorrhage. Based on our findings, it can be concluded that metaplasia of the swim bladder is recurrent in annual fish bred in the laboratory, which explains the large number of unviable larvae. However, its causes remain unknown.(AU)

A criação de peixes anuais é frequentemente comprometida pela ocorrência de peixes que não inflam a vesícula gasosa após a eclosão. Estes peixes não têm capacidade de se manter e nadar na coluna d'água e se locomovem no fundo da água, por isso são chamados belly-sliders. Portanto, objetivamos entender os fatores subjacentes à inflação falhada da bexiga natatória no peixe anual Austrolebias nigrofasciatus e determinar as implicações dessa condição no crescimento de juvenis. Para identificar de que forma o enchimento inicial da vesícula gasosa é comprometido, e determinar as implicações desta condição no crescimento dos juvenis, analisamos histologicamente a vesícula gasosa de peixes com natação normal e de belly-sliders durante o crescimento inicial (primeiro mês de vida). Verificamos que os belly-sliders apresentam metaplasia com descamação do epitélio da vesícula gasosa e presença de hemorragia, além de apresentar crescimento mais lento em relação aos peixes com natação normal. Concluímos que a incidência desta patologia é um problema recorrente e de grande relevância para a manutenção de peixes anuais em laboratório, sendo responsável por uma grande quantidade de juvenis inviáveis, no entanto suas causas permanecem desconhecidas.(AU)

Colorful invasion in permissive Neotropical ecosystems: establishment of ornamental non-native poeciliids of the genera Poecilia/Xiphophorus (Cyprinodontiformes: Poeciliidae) and management alternatives

Headwater creeks are environments susceptible to invasion by non-native fishes. We evaluated the reproduction of 22 populations of the non-native livebearers guppy Poecilia reticulata, black molly Poecilia sphenops, Yucatan molly Poecilia velifera, green swordtail Xiphophorus hellerii, southern platyfish Xiphophorus maculatus, and variable platyfish Xiphophorus variatus during an annual cycle in five headwater creeks located in the largest South American ornamental aquaculture center, Paraíba do Sul River basin, southeastern Brazil. With few exceptions, females of most species were found reproducing (stages 2, 3, 4) all year round in the creeks and gravid females of all species showed small sizes indicating stunting. Juveniles were frequent in all sites. The fecundity of the six poeciliids was always low in all periods. The sex ratio was biased for females in most species, both bimonthly as for the whole period. Water temperature, water level and rainfall were not significantly correlated with reproduction in any species. Therefore, most populations appeared well established. The pertinence of different management actions, such as devices to prevent fish escape, eradication with rotenone and research about negative effects on native species, is discussed in the light of current aquaculture practices in the region.(AU)

Riachos de cabeceira são ambientes susceptíveis à invasão por peixes não-nativos. Neste trabalho, avaliou-se a reprodução de 22 populações dos poecilídeos não-nativos guppy Poecilia reticulata, molinésia preta Poecilia sphenops, molinésia Poecilia velifera, espadinha Xiphophorus hellerii, plati Xiphophorus maculatus e plati variado Xiphophorus variatus durante diferentes anos em cinco riachos de cabeceira localizados no maior polo de piscicultura ornamental da América do Sul, bacia do rio Paraíba do Sul, sudeste do Brasil. Foram encontradas fêmeas da maioria das espécies em reprodução (estágios 2, 3, 4), durante todos os anos nos riachos e fêmeas grávidas de todas as espécies apresentaram pequeno tamanho indicando nanismo. Juvenis de todas as espécies foram frequentes em todos os locais. A fecundidade das seis espécies sempre foi baixa em todos os períodos. Para os períodos bimestrais e totais, encontrou-se mais fêmeas que machos na maioria das espécies. Temperatura e nível de água dos riachos, bem como precipitação pluviométrica não foram correlacionadas com a reprodução. Todas as populações estão estabelecidas nos locais e ações de gerenciamento como dispositivos para impedir a fuga de peixes, erradicação com rotenona e pesquisa científica sobre os efeitos negativos nas espécies nativas são discutidas em relação às práticas de piscicultura na região.(AU)

Colorful invasion in permissive Neotropical ecosystems: establishment of ornamental non-native poeciliids of the genera Poecilia/Xiphophorus (Cyprinodontiformes: Poeciliidae) and management alternatives

Headwater creeks are environments susceptible to invasion by non-native fishes. We evaluated the reproduction of 22 populations of the non-native livebearers guppy Poecilia reticulata, black molly Poecilia sphenops, Yucatan molly Poecilia velifera, green swordtail Xiphophorus hellerii, southern platyfish Xiphophorus maculatus, and variable platyfish Xiphophorus variatus during an annual cycle in five headwater creeks located in the largest South American ornamental aquaculture center, Paraíba do Sul River basin, southeastern Brazil. With few exceptions, females of most species were found reproducing (stages 2, 3, 4) all year round in the creeks and gravid females of all species showed small sizes indicating stunting. Juveniles were frequent in all sites. The fecundity of the six poeciliids was always low in all periods. The sex ratio was biased for females in most species, both bimonthly as for the whole period. Water temperature, water level and rainfall were not significantly correlated with reproduction in any species. Therefore, most populations appeared well established. The pertinence of different management actions, such as devices to prevent fish escape, eradication with rotenone and research about negative effects on native species, is discussed in the light of current aquaculture practices in the region.(AU)

Riachos de cabeceira são ambientes susceptíveis à invasão por peixes não-nativos. Neste trabalho, avaliou-se a reprodução de 22 populações dos poecilídeos não-nativos guppy Poecilia reticulata, molinésia preta Poecilia sphenops, molinésia Poecilia velifera, espadinha Xiphophorus hellerii, plati Xiphophorus maculatus e plati variado Xiphophorus variatus durante diferentes anos em cinco riachos de cabeceira localizados no maior polo de piscicultura ornamental da América do Sul, bacia do rio Paraíba do Sul, sudeste do Brasil. Foram encontradas fêmeas da maioria das espécies em reprodução (estágios 2, 3, 4), durante todos os anos nos riachos e fêmeas grávidas de todas as espécies apresentaram pequeno tamanho indicando nanismo. Juvenis de todas as espécies foram frequentes em todos os locais. A fecundidade das seis espécies sempre foi baixa em todos os períodos. Para os períodos bimestrais e totais, encontrou-se mais fêmeas que machos na maioria das espécies. Temperatura e nível de água dos riachos, bem como precipitação pluviométrica não foram correlacionadas com a reprodução. Todas as populações estão estabelecidas nos locais e ações de gerenciamento como dispositivos para impedir a fuga de peixes, erradicação com rotenona e pesquisa científica sobre os efeitos negativos nas espécies nativas são discutidas em relação às práticas de piscicultura na região.(AU)

A macroscopic classification of the embryonic development of the one-sided livebearer Jenynsia multidentata (Teleostei: Anablepidae)

This study proposes eight stages according to the main discernible changes recorded throughout the embryonic development of Jenynsia multidentata. The development of morphological embryo structures, pigmentation, and changes in tissues connecting mother and embryo were included in the stage characterization. From the fertilized egg (Stage 1), an embryo reaches the intermediary stages when presenting yolk syncytial layer (Stage 2), initial pigmentation of the outer layers of the retina and dorsal region of the head (Stage 3), and the sprouting of the caudal (Stage 4), dorsal and anal fins (Stage 5). During the later stages, the ovarian folds enter the gills, and the body pigmentation becomes more intense (Stage 6), the body becomes elongated (Stage 7), and there is a greater intensity in body pigmentation and increased muscle mass (Stage 8). The dry weight of the batches varied between 0.6 ± 0.3 mg (Stage 3) to 54.6 ± 19.7 mg (Stage 8), but the dry weight of the maternal-embryonic connecting tissues remained almost constant. After controlling the effect of those reproductive tissues, the gain in dry weight of the batches throughout development increased exponentially from Stage 6, reflecting the increase in size and weight of the embryos due to matrotrophy.(AU)

Este estudio propone una clasificación constituida por ocho etapas, establecidas con base en los principales cambios macroscópicos registrados a lo largo del desarrollo embrionario de Jenynsia multidentata. El desarrollo de estructuras embrionarias, los patrones de pigmentación y los cambios en los tejidos de conexión entre la madre y el embrión fueron incluidos en la caracterización de cada etapa. Inicia con el huevo fertilizado (Etapa 1), siguiendo con etapas intermedias del embrión en las cuales es visible la capa sincitial del vitelo (Etapa 2), la pigmentación inicial de las capas externas de la retina y el dorso de la cabeza (Etapa 3), y la aparición de las aletas caudal (Etapa 4), dorsal y anal (Etapa 5). En las etapas posteriores, los pliegues del tejido ovárico se introducen por las branquias y se intensifica la pigmentación corporal (Etapa 6), el cuerpo se extiende (Etapa 7) y hay un marcado aumento en la pigmentación corporal y masa muscular (Etapa 8). El peso seco de los lotes varió entre 0,6 ± 0,3 mg (Etapa 3) y 54,6 ± 19,7 mg (Etapa 8); sin embargo, el peso seco del tejido que conecta a la madre con el embrión se mantuvo prácticamente constante. Después de controlar el efecto del peso seco de estos tejidos, la ganancia de peso seco de los lotes de embriones a lo largo del desarrollo aumentó de forma exponencial a partir de la Etapa 6, evidenciándose en el aumento en tamaño y peso de los embriones debido a la matrotrofia.(AU)