Building a baseline: a survey of the composition and distribution of the ichthyofauna of Guanabara Bay, a deeply impacted estuary

Biodiversity baselines are essential subsidies to evaluate how environmental changes and human impacts affect the special and temporal patterns of communities. This information is paramount to promote proper conservation and management for historically impacted environments such as Guanabara Bay, in southeastern Brazil. Here, we propose an ichthyofaunal baseline for this bay using gathered past data from 1889 to 2020, including literature records, scientific collections, biological sampling, and fisheries landing monitoring. A total of 220 species (203 teleosts and 17 elasmobranchs), distributed in 149 genera (136 teleosts and 13 elasmobranchs) and 72 families (61 teleosts and 11 elasmobranchs) were recorded, including the first record of a tiger-shark, Galeocerdo cuvier, in Guanabara Bay. Although the employed sampling effort was sufficient to represent the ichthyofauna in the middle and upper estuary, the Chao2 estimator indicates an even greater richness regarding the bay as a whole. Evidence of reduced abundance and probable local extinction over the decades was found, supporting the importance of implementing management and conservation strategies in the area. The ichthyofaunal distribution analyses revealed that areas close to conservation units are richer compared to their surroundings, indicating that this is an effective strategy to mitigate human impacts in the bay.(AU)

Esforços de caracterização da biodiversidade são subsídios essenciais para avaliar como mudanças ambientais e impactos antrópicos afetam os padrões espaciais e temporais das comunidades. Essas informações são essenciais para promover conservação e manejo adequados em ambientes historicamente impactados como a Baía de Guanabara, no sudeste do Brasil. Aqui, nós propomos uma linha de referência da ictiofauna dessa baía utilizando dados pretéritos de 1889 a 2020, incluindo registros de literatura, coleções científicas, coletas biológicas e monitoramento de desembarque pesqueiro. Um total de 220 espécies (203 teleósteos e 17 elasmobrânquios), distribuídas em 149 gêneros (136 teleósteos e 13 elasmobrânquios) e 72 famílias (61 teleósteos e 11 elasmobrânquios) foram registradas, incluindo o primeiro registro de tubarão-tigre, Galeocerdo cuvier, na Baía de Guanabara. Apesar do esforço amostral empregado ter sido suficiente para representar a ictiofauna do médio e alto estuário, o estimador Chao2 indicou uma riqueza ainda maior para a baía como um todo. Evidências de redução de abundância e de provável extinção local de táxons ao longo das décadas foram encontradas, corroborando a importância da implantação de medidas de manejo e conservação para a área. A análise da distribuição da ictiofauna revelou que áreas próximas a unidades de conservação são mais ricas em comparação ao seu entorno, indicando que essa é uma estratégia efetiva para mitigar os impactos antrópicos na baía.(AU)

Patterns of ichthyofaunal diversity and distribution across Jebba hydro-electric power (HEP) dam, Jebba, north-central Nigeria / Padrões de diversidade e distribuição da ictiofauna na barragem de hidroelétricas (HEP) de Jebba, Jebba, Nigéria norte-central

The ichthyofauna diversity of the Jebba Hydroelectric Power (HEP) Dam, Jebba, North-central Nigeria was studied. Fishes were sampled for 24 months using gill net, hook and line, and cast net. Individuals were identified using morphological and molecular (mitochondrial Cytochrome c Oxidase subunit I) data. A total of 9605 freshwater fishes were recorded during the sampling period. The use of an integrative taxonomic approach enabled the identification of 83 species belonging to 42 genera. Additionally, the study recorded three unidentified species Ctenopoma sp, Malapterurus sp., and Protopterus sp. Analyses showed that individuals belonging to families Cichlidae and Mochokidae dominated the dam. The diversity analyses revealed relatively high fish diversity during the rainy season at the downstream section of Jebba HEP dam compared to the upstream section. The study, therefore, showed the presence of a diverse fish community comprising high species richness and diversity across the Jebba HEP dam. Finally, we recommend proper biodiversity monitoring and assessment of freshwater fish diversity across Nigeria. In addition, the use of an integrated taxonomic approach is recommended for appropriate species identification and studies of freshwater fishes from Nigeria.(AU)

A diversidade da ictiofauna da hidrelétrica de Jebba (HEP), Jebba, centro-norte da Nigéria foi estudada. Os peixes foram amostrados por 24 meses, utilizando rede de emalhar, anzol e linha, e rede de arrasto. Os indivíduos foram identificados usando a abordagem combinada morfológica e molecular (citocromo c Oxidase mitocondrial subunidade I). Um total de 9605 peixes de água doce foram registrados durante o período de amostragem. A identificação das espécies utilizando a abordagem taxonômica integrada possibilitou a identificação de 83 espécies pertencentes a 42 gêneros. Além disso, o estudo registrou três espécies não identificadas - Ctenopoma sp, Malapterurus sp e Protopterus sp. Análises mostraram que indivíduos pertencentes às famílias Cichlidae e Mochokidae dominaram a barragem. As análises dos índices de diversidade revelaram uma diversidade de peixes relativamente alta durante a estação chuvosa na seção a jusante da barragem Jebba HEP em comparação com a seção a montante. O estudo mostrou, portanto, a presença de diversas comunidades de peixes, que incluem alta riqueza e diversidade de espécies através da barragem Jebba HEP. Finalmente, recomendamos o monitoramento adequado da biodiversidade e a avaliação da diversidade de peixes de água doce em toda a Nigéria. Além disso, recomenda-se o uso de abordagem taxonômica integrada para a identificação adequada das espécies e estudos de peixes de água doce da Nigéria.(AU)

Patterns of ichthyofaunal diversity and distribution across Jebba Hydro-Electric Power (HEP) dam, Jebba, north-central Nigeria / Padrões de diversidade e distribuição da ictiofauna na barragem de hidroelétricas (HEP) de Jebba, Jebba, Nigéria norte-central

The ichthyofauna diversity of the Jebba Hydroelectric Power (HEP) Dam, Jebba, North-central Nigeria was studied. Fishes were sampled for 24 months using gill net, hook and line, and cast net. Individuals were identified using morphological and molecular (mitochondrial Cytochrome c Oxidase subunit I) data. A total of 9605 freshwater fishes were recorded during the sampling period. The use of an integrative taxonomic approach enabled the identification of 83 species belonging to 42 genera. Additionally, the study recorded three unidentified species ­ Ctenopoma sp, Malapterurus sp., and Protopterus sp. Analyses showed that individuals belonging to families Cichlidae and Mochokidae dominated the dam. The diversity analyses revealed relatively high fish diversity during the rainy season at the downstream section of Jebba HEP dam compared to the upstream section. The study, therefore, showed the presence of a diverse fish community comprising high species richness and diversity across the Jebba HEP dam. Finally, we recommend proper biodiversity monitoring and assessment of freshwater fish diversity across Nigeria. In addition, the use of an integrated taxonomic approach is recommended for appropriate species' identification and studies of freshwater fishes from Nigeria.

A diversidade da ictiofauna da hidrelétrica de Jebba (HEP), Jebba, centro-norte da Nigéria foi estudada. Os peixes foram amostrados por 24 meses, utilizando rede de emalhar, anzol e linha, e rede de arrasto. Os indivíduos foram identificados usando a abordagem combinada morfológica e molecular (citocromo c Oxidase mitocondrial subunidade I). Um total de 9605 peixes de água doce foram registrados durante o período de amostragem. A identificação das espécies utilizando a abordagem taxonômica integrada possibilitou a identificação de 83 espécies pertencentes a 42 gêneros. Além disso, o estudo registrou três espécies não identificadas - Ctenopoma sp, Malapterurus sp e Protopterus sp. Análises mostraram que indivíduos pertencentes às famílias Cichlidae e Mochokidae dominaram a barragem. As análises dos índices de diversidade revelaram uma diversidade de peixes relativamente alta durante a estação chuvosa na seção a jusante da barragem Jebba HEP em comparação com a seção a montante. O estudo mostrou, portanto, a presença de diversas comunidades de peixes, que incluem alta riqueza e diversidade de espécies através da barragem Jebba HEP. Finalmente, recomendamos o monitoramento adequado da biodiversidade e a avaliação da diversidade de peixes de água doce em toda a Nigéria. Além disso, recomenda-se o uso de abordagem taxonômica integrada para a identificação adequada das espécies e estudos de peixes de água doce da Nigéria.

Patterns of ichthyofaunal diversity and distribution across Jebba Hydro-Electric Power (HEP) dam, Jebba, north-central Nigeria

Abstract The ichthyofauna diversity of the Jebba Hydroelectric Power (HEP) Dam, Jebba, North-central Nigeria was studied. Fishes were sampled for 24 months using gill net, hook and line, and cast net. Individuals were identified using morphological and molecular (mitochondrial Cytochrome c Oxidase subunit I) data. A total of 9605 freshwater fishes were recorded during the sampling period. The use of an integrative taxonomic approach enabled the identification of 83 species belonging to 42 genera. Additionally, the study recorded three unidentified species Ctenopoma sp, Malapterurus sp., and Protopterus sp. Analyses showed that individuals belonging to families Cichlidae and Mochokidae dominated the dam. The diversity analyses revealed relatively high fish diversity during the rainy season at the downstream section of Jebba HEP dam compared to the upstream section. The study, therefore, showed the presence of a diverse fish community comprising high species richness and diversity across the Jebba HEP dam. Finally, we recommend proper biodiversity monitoring and assessment of freshwater fish diversity across Nigeria. In addition, the use of an integrated taxonomic approach is recommended for appropriate species identification and studies of freshwater fishes from Nigeria.

Resumo A diversidade da ictiofauna da hidrelétrica de Jebba (HEP), Jebba, centro-norte da Nigéria foi estudada. Os peixes foram amostrados por 24 meses, utilizando rede de emalhar, anzol e linha, e rede de arrasto. Os indivíduos foram identificados usando a abordagem combinada morfológica e molecular (citocromo c Oxidase mitocondrial subunidade I). Um total de 9605 peixes de água doce foram registrados durante o período de amostragem. A identificação das espécies utilizando a abordagem taxonômica integrada possibilitou a identificação de 83 espécies pertencentes a 42 gêneros. Além disso, o estudo registrou três espécies não identificadas - Ctenopoma sp, Malapterurus sp e Protopterus sp. Análises mostraram que indivíduos pertencentes às famílias Cichlidae e Mochokidae dominaram a barragem. As análises dos índices de diversidade revelaram uma diversidade de peixes relativamente alta durante a estação chuvosa na seção a jusante da barragem Jebba HEP em comparação com a seção a montante. O estudo mostrou, portanto, a presença de diversas comunidades de peixes, que incluem alta riqueza e diversidade de espécies através da barragem Jebba HEP. Finalmente, recomendamos o monitoramento adequado da biodiversidade e a avaliação da diversidade de peixes de água doce em toda a Nigéria. Além disso, recomenda-se o uso de abordagem taxonômica integrada para a identificação adequada das espécies e estudos de peixes de água doce da Nigéria.

Ichthyofauna of Trairí river basin, Rio Grande do Norte state, northeastern Brazil: a century after the study of the naturalist Edwin Starks in the Papari lagoon

Fishes from the coastal basins of the Mid-Northeastern Caatinga ecoregion (MNCE) were first sampled by the Stanford expedition at the beginning of the 20th century, and published by Edwin C. Starks in 1913. This material included specimens from the Papary lake (= Papari lagoon) in the lower portion of the Trairí river basin, draining towards the eastern coast of Rio Grande do Norte State. In 1941, Henry Fowler provided a broad taxonomic study of the freshwater fishes from northeastern Brazil, including material from the Papari lagoon, besides describing four species assigned to this locality. However, these previous surveys focused only in the lower portion of the Trairí river basin and might be incomplete. Given this framework, the present study aimed at perform a wide ichthyofaunal inventory of Trairí river basin and compare with previously surveys performed in the regions. In 2013 and 2014, four expeditions along the whole basin, including the Papari lagoon itself, resulted in 28 species of fishes belonging to 17 families and seven orders. At Papari lagoon area 16 species were registered whereas 26 and 18 species were recorded by Starks and Fowler’s studies, respectively. Considering all records, 50 species were documented in the basin with 14 (28%) new records, including Serrapinnus potiguar, whose distribution was extended to the south. Two species described by Fowler, Pimelodella papariae and Pseudancistrus papariae, were not found in this study or in any fish collection, and are only known from their type-material. These two species can be naturally rare, locally extinct, or there were inaccuracies in their type-locality. However, species of these genera are only found in larger basins of the MNCE, which drains to the north, corroborating the latter assumption...

Continental fishes from the Tambaba Environmentally Protected Area, Paraíba State, Brazil

Tambaba environmentally protected area is situated on the south coast of Paraíba State, within the Atlantic forest biome of the northeastern region in Brazil. The Tambaba environmentally protected area consists of a series of independent drainages: Graú, Mucatú, and Bucatú river micro-basins, and Caboclo River sub-basin that belongs to Gurugi River micro-basin. Ichthyological samples were collected in five scientific expeditions between months of June and July in 2015. Twenty-nine sites from different habitats (e.g., spanning tributaries, streams, rivers, and estuaries) were accessed for sampling. A total of 44 species distributed within 38 genera, 25 families, and 17 orders were assigned to the Tambaba hydrographic region. Freshwater species comprised 36% (n = 16) and marine-estuarine species 64% (n = 28) of the total collected specimens. Two invasive species occur in the freshwater sites: Cichla monoculus and Poecilia reticulata. Cheirodon jaguaribensis, Cichlasoma orientale, and Crenicichla brasiliensis are endemic to the Brazilian Northeast region with the first species restricted to the Northeast Caatinga and Coastal drainages hydrographic ecoregion.

Ichthyofauna of Trairí river basin, Rio Grande do Norte state, northeastern Brazil: a century after the study of the naturalist Edwin Starks in the Papari lagoon

Fishes from the coastal basins of the Mid-Northeastern Caatinga ecoregion (MNCE) were first sampled by the Stanford expedition at the beginning of the 20th century, and published by Edwin C. Starks in 1913. This material included specimens from the Papary lake (= Papari lagoon) in the lower portion of the Trairí river basin, draining towards the eastern coast of Rio Grande do Norte State. In 1941, Henry Fowler provided a broad taxonomic study of the freshwater fishes from northeastern Brazil, including material from the Papari lagoon, besides describing four species assigned to this locality. However, these previous surveys focused only in the lower portion of the Trairí river basin and might be incomplete. Given this framework, the present study aimed at perform a wide ichthyofaunal inventory of Trairí river basin and compare with previously surveys performed in the regions. In 2013 and 2014, four expeditions along the whole basin, including the Papari lagoon itself, resulted in 28 species of fishes belonging to 17 families and seven orders. At Papari lagoon area 16 species were registered whereas 26 and 18 species were recorded by Starks and Fowlers studies, respectively. Considering all records, 50 species were documented in the basin with 14 (28%) new records, including Serrapinnus potiguar, whose distribution was extended to the south. Two species described by Fowler, Pimelodella papariae and Pseudancistrus papariae, were not found in this study or in any fish collection, and are only known from their type-material. These two species can be naturally rare, locally extinct, or there were inaccuracies in their type-locality. However, species of these genera are only found in larger basins of the MNCE, which drains to the north, corroborating the latter assumption...(AU)

Continental fishes from the Tambaba Environmentally Protected Area, Paraíba State, Brazil

Tambaba environmentally protected area is situated on the south coast of Paraíba State, within the Atlantic forest biome of the northeastern region in Brazil. The Tambaba environmentally protected area consists of a series of independent drainages: Graú, Mucatú, and Bucatú river micro-basins, and Caboclo River sub-basin that belongs to Gurugi River micro-basin. Ichthyological samples were collected in five scientific expeditions between months of June and July in 2015. Twenty-nine sites from different habitats (e.g., spanning tributaries, streams, rivers, and estuaries) were accessed for sampling. A total of 44 species distributed within 38 genera, 25 families, and 17 orders were assigned to the Tambaba hydrographic region. Freshwater species comprised 36% (n = 16) and marine-estuarine species 64% (n = 28) of the total collected specimens. Two invasive species occur in the freshwater sites: Cichla monoculus and Poecilia reticulata. Cheirodon jaguaribensis, Cichlasoma orientale, and Crenicichla brasiliensis are endemic to the Brazilian Northeast region with the first species restricted to the Northeast Caatinga and Coastal drainages hydrographic ecoregion.(AU)

Feeding patterns, trophic structure and damming rivers effect: studies applied in freshwater environments in the Brazilian semi-arid region

The knowledge of the fish trophic structure has been outstanding for providing relevant information on the functioning of the ecosystem in which they are inserted, mainly in dammed environments of semiarid regions that suffer constant changes in the level of water, resulting in alterations, especially in the feeding of the fish due to the variation of the food resources throughout the year, causing changes in the diet of the local ichthyofauna. Within this context, the objective was to describe the trophic categories of fish species in freshwater environments of the Rio Grande do Norte state. Seven trophic guilds were recorded: Detritivore/iliophagous, Insectivorous, Carcinophagous, Piscivorous, Herbivorous and Omnivorous. Through the results, it is observed that the fish species inserted in different environments of the state present the same food pattern, demonstrating flexibility on the diet, prevailing a generalist alimentary habit.(AU)

Feeding patterns, trophic structure and damming rivers effect: studies applied in freshwater environments in the Brazilian semi-arid region

The knowledge of the fish trophic structure has been outstanding for providing relevant information on the functioning of the ecosystem in which they are inserted, mainly in dammed environments of semiarid regions that suffer constant changes in the level of water, resulting in alterations, especially in the feeding of the fish due to the variation of the food resources throughout the year, causing changes in the diet of the local ichthyofauna. Within this context, the objective was to describe the trophic categories of fish species in freshwater environments of the Rio Grande do Norte state. Seven trophic guilds were recorded: Detritivore/iliophagous, Insectivorous, Carcinophagous, Piscivorous, Herbivorous and Omnivorous. Through the results, it is observed that the fish species inserted in different environments of the state present the same food pattern, demonstrating flexibility on the diet, prevailing a generalist alimentary habit.

Patterns of ichthyofaunal diversity and distribution across Jebba Hydro-Electric Power (HEP) dam, Jebba, north-central Nigeria

Abstract The ichthyofauna diversity of the Jebba Hydroelectric Power (HEP) Dam, Jebba, North-central Nigeria was studied. Fishes were sampled for 24 months using gill net, hook and line, and cast net. Individuals were identified using morphological and molecular (mitochondrial Cytochrome c Oxidase subunit I) data. A total of 9605 freshwater fishes were recorded during the sampling period. The use of an integrative taxonomic approach enabled the identification of 83 species belonging to 42 genera. Additionally, the study recorded three unidentified species Ctenopoma sp, Malapterurus sp., and Protopterus sp. Analyses showed that individuals belonging to families Cichlidae and Mochokidae dominated the dam. The diversity analyses revealed relatively high fish diversity during the rainy season at the downstream section of Jebba HEP dam compared to the upstream section. The study, therefore, showed the presence of a diverse fish community comprising high species richness and diversity across the Jebba HEP dam. Finally, we recommend proper biodiversity monitoring and assessment of freshwater fish diversity across Nigeria. In addition, the use of an integrated taxonomic approach is recommended for appropriate species identification and studies of freshwater fishes from Nigeria.

Resumo A diversidade da ictiofauna da hidrelétrica de Jebba (HEP), Jebba, centro-norte da Nigéria foi estudada. Os peixes foram amostrados por 24 meses, utilizando rede de emalhar, anzol e linha, e rede de arrasto. Os indivíduos foram identificados usando a abordagem combinada morfológica e molecular (citocromo c Oxidase mitocondrial subunidade I). Um total de 9605 peixes de água doce foram registrados durante o período de amostragem. A identificação das espécies utilizando a abordagem taxonômica integrada possibilitou a identificação de 83 espécies pertencentes a 42 gêneros. Além disso, o estudo registrou três espécies não identificadas - Ctenopoma sp, Malapterurus sp e Protopterus sp. Análises mostraram que indivíduos pertencentes às famílias Cichlidae e Mochokidae dominaram a barragem. As análises dos índices de diversidade revelaram uma diversidade de peixes relativamente alta durante a estação chuvosa na seção a jusante da barragem Jebba HEP em comparação com a seção a montante. O estudo mostrou, portanto, a presença de diversas comunidades de peixes, que incluem alta riqueza e diversidade de espécies através da barragem Jebba HEP. Finalmente, recomendamos o monitoramento adequado da biodiversidade e a avaliação da diversidade de peixes de água doce em toda a Nigéria. Além disso, recomenda-se o uso de abordagem taxonômica integrada para a identificação adequada das espécies e estudos de peixes de água doce da Nigéria.

Temporal dynamics of a fish community in the lower portion of a tidal creek, Pando sub-estuarine system, Uruguay

ABSTRACT Estuaries are highly dynamic ecosystems subjected to variability of their fish communities over different time scales. The nearshore fish community of the lower Pando estuary, a temperate sub-system of the Río de la Plata estuary, was sampled from May 2002 to June 2003. A total of 2,165 fishes, represented by 16 species were caught by seine netting. Captures were dominated by juveniles (>90%), as well as by the sciaenid Micropogonias furnieri (Desmarest, 1823) (82.8%). The fish community showed high seasonal variability, with the greatest diversity and biomass in summer and spring and the highest species richness during summer. Lowest values of all community parameters occurred in winter and autumn, seasons that presented the highest similarity in fish composition. Number of species was correlated with water temperature and salinity. The ichthyofaunal composition showed significant diel differences in summer and spring. Diel changes were observed in the density of M. furnieri and Odontesthes argentinensis (Valenciennes, 1835), occurring mainly during the day, and of Mugil liza Valenciennes, 1836, Parapimelodus valenciennis (Lütken, 1874) and Brevoortia aurea (Spix & Agassiz, 1829), caught mostly during the night. Temporal variability was attributed to environmental fluctuations, life cycle of species as well as to feeding patterns and small-scale displacements. Presented findings in the Pando sub-estuary denote similar juvenile use and seasonal patterns to those found in estuaries. Further studies in the nursery function and juvenile dynamics over the year are recommended in order to better understand the ecological role of sub-estuaries.

RESUMO Os estuários são ecossistemas dinâmicos que apresentam variabilidade nas suas comunidades de peixes em diferentes escalas de tempo. A comunidade de peixes costeiros do baixo estuário do Pando, um subsistema temperado do estuário do Río de la Plata, foi amostrada entre maio de 2002 e junho de 2003. Um total de 2.165 peixes, representados por 16 espécies, foi documentado com a pesca de arrasto. As capturas foram dominadas pelos jovens (>90%), assim como pelo sciaenídeo Micropogonias furnieri (Desmarest, 1823) (82,8%). A comunidade de peixes apresentou uma grande mudança sazonal, com a máxima diversidade e biomassa no verão e primavera, e a máxima riqueza de espécies durante o verão. Os menores valores de todos os parâmetros comunitários ocorreram no inverno e outono, estações com a maior similaridade na composição da ictiofauna. O número de espécies foi correlacionado com a temperatura de água e salinidade. A composição da ictiofauna apresentou mudanças significativas diárias no verão e primavera. Verificou-se uma variabilidade diária na densidade da M. furnieri e Odontesthes argentinensis (Valenciennes, 1835), ocorrendo principalmente durante o dia, e de Mugil liza Valenciennes, 1836, Parapimelodus valenciennis (Lütken, 1874) e Brevoortia aurea (Spix & Agassiz, 1829), observadas principalmente durante à noite. A variabilidade temporal foi atribuída a interação com o ambiente, ciclo de vida das espécies assim como a atividade alimentar e movimentos de pequena escala. Resultados no subestuário Pando denotam um uso de juvenis e padrões sazonais semelhante aos dos estuários. Mais pesquisas no papel das áreas de berçário e dinâmicas juvenis ao longo do ano são recomendadas para compreender melhor o papel ecológico dos subestuários.

Temporal dynamics of a fish community in the lower portion of a tidal creek, Pando sub-estuarine system, Uruguay / Dinâmica temporal de uma comunidade de peixes na parte baixa de um arroio costeiro, sistema subestuarino Pando, Uruguai

Estuaries are highly dynamic ecosystems subjected to variability of their fish communities over different time scales. The nearshore fish community of the lower Pando estuary, a temperate sub-system of the Río de la Plata estuary, was sampled from May 2002 to June 2003. A total of 2,165 fishes, represented by 16 species were caught by seine netting. Captures were dominated by juveniles (>90%), as well as by the sciaenid Micropogonias furnieri (Desmarest, 1823) (82.8%). The fish community showed high seasonal variability, with the greatest diversity and biomass in summer and spring and the highest species richness during summer. Lowest values of all community parameters occurred in winter and autumn, seasons that presented the highest similarity in fish composition. Number of species was correlated with water temperature and salinity. The ichthyofaunal composition showed significant diel differences in summer and spring. Diel changes were observed in the density of M. furnieri and Odontesthes argentinensis (Valenciennes, 1835), occurring mainly during the day, and of Mugil liza Valenciennes, 1836, Parapimelodus valenciennis (Lütken, 1874) and Brevoortia aurea (Spix & Agassiz, 1829), caught mostly during the night. Temporal variability was attributed to environmental fluctuations, life cycle of species as well as to feeding patterns and small-scale displacements. Presented findings in the Pando sub-estuary denote similar juvenile use and seasonal patterns to those found in estuaries. Further studies in the nursery function and juvenile dynamics over the year are recommended in order to better understand the ecological role of sub-estuaries.(AU)

Os estuários são ecossistemas dinâmicos que apresentam variabilidade nas suas comunidades de peixes em diferentes escalas de tempo. A comunidade de peixes costeiros do baixo estuário do Pando, um subsistema temperado do estuário do Río de la Plata, foi amostrada entre maio de 2002 e junho de 2003. Um total de 2.165 peixes, representados por 16 espécies, foi documentado com a pesca de arrasto. As capturas foram dominadas pelos jovens (>90%), assim como pelo sciaenídeo Micropogonias furnieri (Desmarest, 1823) (82,8%). A comunidade de peixes apresentou uma grande mudança sazonal, com a máxima diversidade e biomassa no verão e primavera, e a máxima riqueza de espécies durante o verão. Os menores valores de todos os parâmetros comunitários ocorreram no inverno e outono, estações com a maior similaridade na composição da ictiofauna. O número de espécies foi correlacionado com a temperatura de água e salinidade. A composição da ictiofauna apresentou mudanças significativas diárias no verão e primavera. Verificou-se uma variabilidade diária na densidade da M. furnieri e Odontesthes argentinensis (Valenciennes, 1835), ocorrendo principalmente durante o dia, e de Mugil liza Valenciennes, 1836, Parapimelodus valenciennis (Lütken, 1874) e Brevoortia aurea (Spix & Agassiz, 1829), observadas principalmente durante à noite. A variabilidade temporal foi atribuída a interação com o ambiente, ciclo de vida das espécies assim como a atividade alimentar e movimentos de pequena escala. Resultados no subestuário Pando denotam um uso de juvenis e padrões sazonais semelhante aos dos estuários. Mais pesquisas no papel das áreas de berçário e dinâmicas juvenis ao longo do ano são recomendadas para compreender melhor o papel ecológico dos subestuários.(AU)

Temporal dynamics of a fish community in the lower portion of a tidal creek, Pando sub-estuarine system, Uruguay / Dinâmica temporal de uma comunidade de peixes na parte baixa de um arroio costeiro, sistema subestuarino Pando, Uruguai

Estuaries are highly dynamic ecosystems subjected to variability of their fish communities over different time scales. The nearshore fish community of the lower Pando estuary, a temperate sub-system of the Río de la Plata estuary, was sampled from May 2002 to June 2003. A total of 2,165 fishes, represented by 16 species were caught by seine netting. Captures were dominated by juveniles (>90%), as well as by the sciaenid Micropogonias furnieri (Desmarest, 1823) (82.8%). The fish community showed high seasonal variability, with the greatest diversity and biomass in summer and spring and the highest species richness during summer. Lowest values of all community parameters occurred in winter and autumn, seasons that presented the highest similarity in fish composition. Number of species was correlated with water temperature and salinity. The ichthyofaunal composition showed significant diel differences in summer and spring. Diel changes were observed in the density of M. furnieri and Odontesthes argentinensis (Valenciennes, 1835), occurring mainly during the day, and of Mugil liza Valenciennes, 1836, Parapimelodus valenciennis (Lütken, 1874) and Brevoortia aurea (Spix & Agassiz, 1829), caught mostly during the night. Temporal variability was attributed to environmental fluctuations, life cycle of species as well as to feeding patterns and small-scale displacements. Presented findings in the Pando sub-estuary denote similar juvenile use and seasonal patterns to those found in estuaries. Further studies in the nursery function and juvenile dynamics over the year are recommended in order to better understand the ecological role of sub-estuaries.

Os estuários são ecossistemas dinâmicos que apresentam variabilidade nas suas comunidades de peixes em diferentes escalas de tempo. A comunidade de peixes costeiros do baixo estuário do Pando, um subsistema temperado do estuário do Río de la Plata, foi amostrada entre maio de 2002 e junho de 2003. Um total de 2.165 peixes, representados por 16 espécies, foi documentado com a pesca de arrasto. As capturas foram dominadas pelos jovens (>90%), assim como pelo sciaenídeo Micropogonias furnieri (Desmarest, 1823) (82,8%). A comunidade de peixes apresentou uma grande mudança sazonal, com a máxima diversidade e biomassa no verão e primavera, e a máxima riqueza de espécies durante o verão. Os menores valores de todos os parâmetros comunitários ocorreram no inverno e outono, estações com a maior similaridade na composição da ictiofauna. O número de espécies foi correlacionado com a temperatura de água e salinidade. A composição da ictiofauna apresentou mudanças significativas diárias no verão e primavera. Verificou-se uma variabilidade diária na densidade da M. furnieri e Odontesthes argentinensis (Valenciennes, 1835), ocorrendo principalmente durante o dia, e de Mugil liza Valenciennes, 1836, Parapimelodus valenciennis (Lütken, 1874) e Brevoortia aurea (Spix & Agassiz, 1829), observadas principalmente durante à noite. A variabilidade temporal foi atribuída a interação com o ambiente, ciclo de vida das espécies assim como a atividade alimentar e movimentos de pequena escala. Resultados no subestuário Pando denotam um uso de juvenis e padrões sazonais semelhante aos dos estuários. Mais pesquisas no papel das áreas de berçário e dinâmicas juvenis ao longo do ano são recomendadas para compreender melhor o papel ecológico dos subestuários.

New species of the catfish genus Tatia (Siluriformes: Auchenipteridae) from the rio Teles Pires, upper rio Tapajós basin, Brazil

Analysis of specimens of the auchenipterid catfish genus Tatia collected in the rio Teles Pires, a tributary of the rio Tapajós, along the border between the states of Pará and Mato Grosso, Brazil, revealed it to be an undescribed species. This new species is distinguished from all congeners with the exception of T. carolae and T. musaica by the intense, clearly demarcated, dark coloration on the dorsal and to varying degrees lateral and sometimes ventrolateral portions of the body versus the very lightly colored regions which are translucent in life on the remainder of the body. Various details of head, body and dorsal and caudal-fin pigmentation along with meristic and morphometric features distinguish the new species from T. carolae and T. musaica. The new species provides further evidence that the upper and middle rio Tapajós is a region of ichthyofaunal endemism.(AU)

A análise de espécimes do bagre auquenipterídeo do gênero Tatia, provenientes do rio Teles Pires, um tributário do rio Tapajós, na divisa entre os estados do Pará e Mato Grosso, Brasil, revelou se tratar de uma espécie ainda não descrita. Esta espécie nova distingue-se de seus congêneres, com exceção de T. carolae e T. musaica, por sua intensa e distintamente demarcada, coloração escura sobre o dorso a variados graus na porção lateral e algumas vezes ventro-lateral do corpo em contraste com regiões de coloração muito clara, a qual é translúcida em vida, no restante do corpo. Vários detalhes da pigmentação da cabeça, corpo, e nadadeira caudal e dorsal juntamente com características merísticas e morfométricas distinguem a espécie nova de T. carolae e T. musaica. A espécie nova fornece evidência adicional de que a porção alta e média da bacia do rio Tapajós é uma região de endemismo da ictiofauna.(AU)

Phylogeographic pattern of Jenynsia multidentata (Cyprinodontiformes: Anablepidae) in the southern boundary of the Brazilian Subregion, Argentina

The Atlantic drainage basins are located in the southern Pampean area, in the southernmost part of the Brazilian subregion. Tectonic and paleoclimatic phenomena, occurring during the Quaternary, have currently isolated these basins from the present hydrographic system. Their ichthyofaunal composition is similar to that of hydric systems located further northward. Jenynsia multidentata is a species with wide distribution in the Atlantic drainage basins, as well as in those Northern basins. Here we investigated the phylogeographic pattern of Jenynsia multidentata and analyzed its relationships with the paleoclimatic and geologic history of the region. The analysis of the population's assemblage showed moderate genetic diversity, demographic equilibrium and marked genetic structure in the populations that occupy the extremes of the distributional range. The populations in the center of the range did not present genetic diversity, sharing a single haplotype. These results allow inferring that the presence of Jenynsia multidentata in the area results from historical demographic processes that are independent but complementary. In turn, these processes could arise from paleoclimatic changes occurred during the Quaternary.(AU)

Las cuencas de pendiente atlántica del área pampeana Austral son el límite meridional de la subregión Brasílica. Fenómenos tectónicos y paleoclimáticos ocurridos durante el Cuaternario han dejado aisladas a estas cuencas del diseño hidrográfico actual. La composición íctica de estás cuencas es similar a la de los sistemas hídricos ubicados más al norte. Jenynsia multidentata es una especie con un amplia distribución en las cuencas de pendiente atlántica, como así también, en las cuencas ubicadas al norte. En el presente trabajo se investigó el patrón filogeográfico de Jenynsia multidentata, y se examinó la relación entre este patrón y la historia paleoclimática y geológica de la región. En el análisis del conjunto de poblaciones se encontró evidencia de una moderada diversidad genética, equilibrio demográfico, y una marcada estructura poblacional, en las poblaciones que ocupan los extremos de la distribución. Mientras que en las poblaciones que ocupan el centro de la distribución no se encontró diversidad genética presentando un único haplotipo. De los resultados obtenidos se infiere que la presencia de Jenynsia multidentata en el área es el resultado de procesos demográficos históricos independientes pero complementarios. A su vez, estos procesos podrían surgir de los cambios paleoclimáticos ocurridos durante el Cuaternario.(AU)

Spatiotemporal variations of the ichthyofaunal structure accompanying the seabob shrimp, Xiphopenaeus kroyeri (Crustacea: Penaeidae), fishery in important fishery areas of the Santa Catarina shore, Brazil

The present study analyzed qualitatively and quantitatively the temporal and spatial changes in the fish assemblages present in seabob shrimp distribution sites in two important fishing areas of the Santa Catarina coast. Monthly bottom trawls, conducted between March 2007 and February 2008 in Balneário Barra do Sul and Penha, yielded a total of 38,608 specimens belonging to 54 species, of which 35 occurred in both regions. The Sciaenidae was the most represented family in both number of species and abundance of individuals. The dominant species were Stellifer rastrifer (Jordan, 1889), S. brasiliensis (Schultz, 1945), Paralonchurus brasiliensis (Steindachner, 1875), Isopisthus parvipinnis (Cuvier, 1830), Trichiurus lepturus (Linnaeus, 1758), and Pellona harroweri (Fowler, 1917). The ichthyofaunal structure showed a spatiotemporal dependence with significant differences in March 2007 and January and February 2008 between Balneário Barra do Sul and Penha. The main differences were attributed to dominant species, which were responsible for significantly altering the abundance of the assemblages. The species richness was similar in both sites, whereas the diversity and equitability indices showed monthly fluctuation patterns that differed between Balneário Barra do Sul and Penha. The Shannon index differed in August, September and November 2007 and January and February 2008, with an H' ranging from 0.74 to 1.98 influenced by dominant species, whereas significant variations were observed for the Pielou index in November 2007 and February 2008. The Berger-Parker index demonstrated a clear dominance pattern where the monthly numeric contribution of a single species ranged from approximately 30 to 80%. Although the results showed differences between fishing grounds 25% of the time, we conclude that fish assemblies captured as accompanying fauna in artisanal seabob shrimp fisheries showed statistically similar characteristics for most of the year, although Balneário Barra do Sul and Penha are 35 km away from each other.

Spatiotemporal variations of the ichthyofaunal structure accompanying the seabob shrimp, Xiphopenaeus kroyeri (Crustacea: Penaeidae), fishery in important fishery areas of the Santa Catarina shore, Brazil

The present study analyzed qualitatively and quantitatively the temporal and spatial changes in the fish assemblages present in seabob shrimp distribution sites in two important fishing areas of the Santa Catarina coast. Monthly bottom trawls, conducted between March 2007 and February 2008 in Balneário Barra do Sul and Penha, yielded a total of 38,608 specimens belonging to 54 species, of which 35 occurred in both regions. The Sciaenidae was the most represented family in both number of species and abundance of individuals. The dominant species were Stellifer rastrifer (Jordan, 1889), S. brasiliensis (Schultz, 1945), Paralonchurus brasiliensis (Steindachner, 1875), Isopisthus parvipinnis (Cuvier, 1830), Trichiurus lepturus (Linnaeus, 1758), and Pellona harroweri (Fowler, 1917). The ichthyofaunal structure showed a spatiotemporal dependence with significant differences in March 2007 and January and February 2008 between Balneário Barra do Sul and Penha. The main differences were attributed to dominant species, which were responsible for significantly altering the abundance of the assemblages. The species richness was similar in both sites, whereas the diversity and equitability indices showed monthly fluctuation patterns that differed between Balneário Barra do Sul and Penha. The Shannon index differed in August, September and November 2007 and January and February 2008, with an H' ranging from 0.74 to 1.98 influenced by dominant species, whereas significant variations were observed for the Pielou index in November 2007 and February 2008. The Berger-Parker index demonstrated a clear dominance pattern where the monthly numeric contribution of a single species ranged from approximately 30 to 80%. Although the results showed differences between fishing grounds 25% of the time, we conclude that fish assemblies captured as accompanying fauna in artisanal seabob shrimp fisheries showed statistically similar characteristics for most of the year, although Balneário Barra do Sul and Penha are 35 km away from each other.

Spatiotemporal variations of the ichthyofaunal structure accompanying the seabob shrimp, Xiphopenaeus kroyeri (Crustacea: Penaeidae), fishery in important fishery areas of the Santa Catarina shore, Brazil

The present study analyzed qualitatively and quantitatively the temporal and spatial changes in the fish assemblages present in seabob shrimp distribution sites in two important fishing areas of the Santa Catarina coast. Monthly bottom trawls, conducted between March 2007 and February 2008 in Balneário Barra do Sul and Penha, yielded a total of 38,608 specimens belonging to 54 species, of which 35 occurred in both regions. The Sciaenidae was the most represented family in both number of species and abundance of individuals. The dominant species were Stellifer rastrifer (Jordan, 1889), S. brasiliensis (Schultz, 1945), Paralonchurus brasiliensis (Steindachner, 1875), Isopisthus parvipinnis (Cuvier, 1830), Trichiurus lepturus (Linnaeus, 1758), and Pellona harroweri (Fowler, 1917). The ichthyofaunal structure showed a spatiotemporal dependence with significant differences in March 2007 and January and February 2008 between Balneário Barra do Sul and Penha. The main differences were attributed to dominant species, which were responsible for significantly altering the abundance of the assemblages. The species richness was similar in both sites, whereas the diversity and equitability indices showed monthly fluctuation patterns that differed between Balneário Barra do Sul and Penha. The Shannon index differed in August, September and November 2007 and January and February 2008, with an H' ranging from 0.74 to 1.98 influenced by dominant species, whereas significant variations were observed for the Pielou index in November 2007 and February 2008. The Berger-Parker index demonstrated a clear dominance pattern where the monthly numeric contribution of a single species ranged from approximately 30 to 80%. Although the results showed differences between fishing grounds 25% of the time, we conclude that fish assemblies captured as accompanying fauna in artisanal seabob shrimp fisheries showed statistically similar characteristics for most of the year, although Balneário Barra do Sul and Penha are 35 km away from each other.

Biodiversity, distributions and isolation of microplastics pollution in finfish species in the Panjkora River at Lower and Upper Dir districts of Khyber Pakhtunkhwa province of Pakistan

Abstract The basic aim of this study was aimed to determine the ichthyofaunal diversity of River Panjkora in both upper and lower Dir districts in Khyber Pakhtunkhwa province of Pakistan.Fish samples were collected by using fishnets from March to September 2020. A total of 724 specimens were collected and classified into 5 families, 14 genera, and 18 species. The overall results revealed that most fish fauna of river Panjkora contains 8 species of family Cyprinidae (56.49%) followed by 4 species of Nemacheilidae (24.44%), 2 species of Channidae (10.63%), and Sisoridae (7.04%), and 1 species of Mastacembelidae (1.38%), respectively. Among all kinds of fish species, Schizothorax plagiostomus (16.57%) was highly dominated and followed by Carassius auratus (11.87%) and Racoma labiata (9.66%) and were reported as highly abundant, especially during April, May, and June. The least abundant species were Glyptothorax punjabensis, Glyptothorax sufii, and Mastacembelus armatus, that constituting 2.48%, 2.20%, and 1.38% of the total fish samples. The Overall Simpsons diversity (1-D= 0.919) and Simpsons Reciprocal index values (1/D= 12.3876), and Shannons index (H= 2.68) were indicating that river Panjkora contains a quite rich and diverse group of fish species. The highest microplastics observed in site 7 compared to other study area. Conservation steps should be taken as a top priority to protect and conserve the marine environment and natural heritage from further loss, extinction and stop or minimize losses incurred through irresponsible fishery practices

Resumo O objetivo básico deste estudo foi determinar a diversidade ictiofaunística do rio Panjkora nos distritos de Lower e Upper de Dir, na província de Khyber Pakhtunkhwa, no Paquistão. Amostras de peixes foram coletadas com redes de arrasto de março a setembro de 2020. Foram coletados 724 espécimes, classificados em 5 famílias, 14 gêneros e 18 espécies. Os resultados gerais revelaram que a maioria da ictiofauna do rio Panjkora contém 8 espécies da família Cyprinidae (56,49%), seguidas por 4 espécies de Nemacheilidae (24,44%), 2 espécies de Channidae (10,63%) e Sisoridae (7,04%) e 1 espécie de Mastacembelidae (1,38%). Entre todas as espécies de peixes, Schizothorax plagiostomus (16,57%) foi altamente predominante, seguida por Carassius auratus (11,87%) e Racoma labiata (9,66%), e elas foram relatadas como altamente abundantes, especialmente nos meses de abril, maio e junho. As espécies menos abundantes foram Glyptothorax punjabensis, Glyptothorax sufii e Mastacembelus armatus, que constituíram 2,48%, 2,20% e 1,38%, respectivamente, do total de peixes amostrados. O índice de diversidade de Simpson (1-D = 0,919), o índice recíproco de Simpson (1/D = 12,3876) e o índice de Shannon (H = 2,68) indicaram que o rio Panjkora contém um grupo bastante rico e diversificado de espécies de peixes. Os microplásticos mais altos foram observados no local 7 em comparação com outra área de estudo. Medidas de conservação devem ser tomadas como prioridade máxima para proteger e conservar o ambiente marinho e o patrimônio natural de novas perdas e extinção e para parar ou minimizar as perdas ocorridas por práticas de pesca irresponsáveis.