David Reynalte Tataje - Academia.edu (original) (raw)

Papers by David Reynalte Tataje

The distribution and abundance of fish eggs and larvae was analyzed in three sections of the Uppe... more The distribution and abundance of fish eggs and larvae was analyzed in three sections of the Upper Uruguay river,

ABSTRACT. Understanding the embryogenesis of a species is a useful tool for locating areas for sp... more ABSTRACT. Understanding the embryogenesis of a species is a useful tool for locating areas for spawning and for the study of growth of the species in their natural environment. This study was conducted at the Panamá Fish Hatchery in Santa Catarina, Brazil, to characterize the embryonic development of the piavuçu Leporinus macrocephalus (Characiformes, Anostomidae). Description was based on the analysis of embryos collected at 10-minute intervals during the first three hours after fertilization, and later at 30-minute intervals until larva hatching. Piavuçu eggs are detached, transparent, small, spherical, with a large perivitelline space. Hatching takes place 11 hours and 30 minutes after fertilization at an average temperature of 28.2°C. Total length and weight of recently hatched larva were 2.39 ± 0.12 mm, and 0.5 ± 0.1mg respectively. Key words: Leporinus macrocephalus, fish, embryonic development. RESUMO. Estadios do desenvolvimento embrionário do piavuçu Leporinus macrocephalus...

1 Introducao Dentre os metodos de coleta passiva, as armadilhas luminosas tem sido usadas na amos... more 1 Introducao Dentre os metodos de coleta passiva, as armadilhas luminosas tem sido usadas na amostragem de larvas e juvenis de peixes tanto nos ambientes marinhos como de agua doce, com seu sucesso comprovado em areas de rios, lagos, lagoas e recifes de corais. No entanto, seu uso como metodologia de coleta em ambientes aquaticos brasileiros e praticamente ausente devido a falta de estudos que avaliem sua relevância nestes ecossistemas. 2 Objetivo Avaliar a eficiencia de captura de larvas das armadilhas luminosas. 3 Metodologia O local em que foi realizado o estudo e no Medio rio Uruguai, no Municipio de Porto Lucena (RS), neste trecho o rio apresenta em torno de 1 Km de largura. Foram utilizadas 12 armadilhas cilindroconicas com malha de 500 u m. A iluminacao da armadilha foi proporcionada por uma lampada LEDs de 1 W alimentanda com bateria e fixada na parte dianteira da armadilha. Foram utilizados tres cores diferentes nas armadilhas luminosas: verde, vermelha e branca, sendo tres...

O surubim pintado Pseudoplatystoma corruscans, e uma especie tipica da Bacia do Prata com grande ... more O surubim pintado Pseudoplatystoma corruscans, e uma especie tipica da Bacia do Prata com grande relevância na pesca devido a seu excelente sabor de carne, apesar disso pouco se sabe sobre a ecologia desta especie. Devido a pressao antropica esta especie tem mostrado reducao populacional em diferentes rios do Brasil. No trecho Medio do rio Uruguai pouco se sabe sobre sua distribuicao e se esta conseguindo alcancar sucesso reprodutivo. Nesse sentido, este trabalho tem por objetivo verificar a reproducao do Pseudoplatystoma corruscans no Medio Uruguai. No estudo, foram realizadas coletas mensais de ictioplâncton entre outubro de 2015 a marco de 2016 (periodo reprodutivo), em um trecho do rio Uruguai situado no municipio de Porto Lucena-RS. Para as coletas, foram realizados arrastos utilizado rede planctonica com um formato conico-cilindrico com malha de 500 µm. Mensalmente foram realizados oito amostragens de superficie no inicio da noite. As amostras foram fixadas em formol 4% e leva...

Role of the rain and macrophytes on temporal and spatial pattern of ichthyoplankton in the Caatin... more Role of the rain and macrophytes on temporal and spatial pattern of ichthyoplankton in the Caatinga Biome, Brazil Papel da chuva e das macrófitas no padrão temporal e espacial do ictioplâncton no Bioma Caatinga, Brasil

El genero Brycon abarca 40 especies validas, algunas de estas con gran potencial zootecnico para ... more El genero Brycon abarca 40 especies validas, algunas de estas con gran potencial zootecnico para la piscicultura brasilena, entre las cuales podemos destacar el matrinxa (Brycon amazonicus), la piracanjuba (Brycon orbignyanus), la piabanha (Brycon insignis) y la piraputanga (Brycon hilarii). Dentro de los principales motivos que han despertado el interes de estas especies para la piscicultura se pueden mencionar la optima aceptacion por el mercado consumidor debido a la excelente calidad de la carne, el rapido crecimiento inicial y el habito alimenticio omnivoro con tendencia de consumo de alimentos de origen vegetal. Debido a esta caracteristica alimenticia, estas especies tienden a aceptar facilmente dietas artificiales en cautiverio, ademas de asimilar bien la proteina de origen vegetal, disminuyendo los costos de racion. Las tecnicas para la induccion al desove en cautiverio muestran resultados bastante conocidos, respondiendo bien al protocolo de induccion hormonal para la madu...

ResumenEl gOnero Brycon abarca 40 especies vAElidas, algunas de estas con gran potencial zootOcni... more ResumenEl gOnero Brycon abarca 40 especies vAElidas, algunas de estas con gran potencial zootOcnico parala piscicultura brasileaea, entre las cuales podemos destacar el matrinxa (Brycon amazonicus), lapiracanjuba (Brycon orbignyanus), la piabanha (Brycon insignis) y la piraputanga (Brycon hilarii).Dentro de los principales motivos que han despertado el interOs de estas especies para la pisciculturase pueden mencionar la optima aceptacion por el mercado consumidor debido a la excelente calidadde la carne, el rAEpido crecimiento inicial y el hAEbito alimenticio omnivoro con tendencia de consumode alimentos de origen vegetal. Debido a esta caracteristica alimenticia, estas especies tienden aaceptar fAEcilmente dietas artificiales en cautiverio, ademAEs de asimilar bien la proteina de origenvegetal, disminuyendo los costos de racion. Las tOcnicas para la induccion al desove en cautiveriomuestran resultados bastante conocidos, respondiendo bien al protocolo de induccion hormonal parala m...

EntomoBrasilis

Adult females of most black flies species (Diptera, Simuliidae) exhibit a blood-sucking habit. Im... more Adult females of most black flies species (Diptera, Simuliidae) exhibit a blood-sucking habit. Immature stages develop in water courses and are important in the ecology of lotic environments. We aim to understand the distribution of immature simuliids in the hydrographic sub-basin of the Comandaí river, in Northwest of Rio Grande do Sul, Brazil. For that purpose, simuliids were sampled in three stretches (source, intermediate and mouth) of nine streams, distributed along the three main regions of the sub-basin. Evaluations of the influence of abiotic factors in different spatial and temporal scales were made. Sampling was carried out in two seasons: between September and November 2016 (spring), and between April and July 2017 (autumn). In total, 17,146 individuals were sampled (larvae of last instars and pupae), which resulted in the identification of eleven Simuliidae species. The most abundant species were Simulium pertinax Kollar (77.55%), followed by Simulium incrustatum Lutz (1...

EntomoBrasilis

In southern Brazil there are several problems regarding the hematophageal activity of black flies... more In southern Brazil there are several problems regarding the hematophageal activity of black flies, and the information on the distribution of species are still insufficient. In this study, our main goals were to recognize Simuliidae species and to analyze abiotic factors regarding the distribution of immature stages (larva and pupa) in streams from the Ijuí River basin, Northwest of Rio Grande do Sul, Brazil. We sampled simulids specimens in 27 study sites, covering three regions (high, intermediate and low altitude). Concomitantly, we recorded abiotic factors in the studied sites, such as: temperature, electrical conductivity, dissolved oxygen, atmospheric pressure, pH, altitude and stream width. For data analysis, we performed Kruskal-Wallis, ANOVA, Principal Component Analysis (PCA), Analysis of Indicator Species and Canonical Correspondence (CCA). A total of 10 species of black Flies was recorded. Simulium pertinax Kollar, Simulium incrustatum Lutz and Simulium orbitale Lutz were the most frequent. There was no significant difference in richness and density of the species between the different regions studied, except for Simulium jujuyense Paterson & Shannon. The sampled environments were segregated according to the location within the basin, and only S. jujuyense was considered an indicator species of the upper region. These results can be explained by the homogeneous conditions of the Ijuí River basin, which have suffered anthropogenic pressure mainly due to agricultural activities, resulting in losses in local aquatic biodiversity. Also, it may indicate that the control must be conducted considering the basin as a whole, and not only as isolated stretches of the streams.

Acta Scientiarum. Animal Sciences, 2008

Understanding the embryogenesis of a species is a useful tool for locating areas for spawning and... more Understanding the embryogenesis of a species is a useful tool for locating areas for spawning and for the study of growth of the species in their natural environment. This study was conducted at the Panamá Fish Hatchery in Santa Catarina, Brazil, to characterize the embryonic development of the piavuçu Leporinus macrocephalus (Characiformes, Anostomidae). Description was based on the analysis of embryos collected at 10-minute intervals during the first three hours after fertilization, and later at 30-minute intervals until larva hatching. Piavuçu eggs are detached, transparent, small, spherical, with a large perivitelline space. Hatching takes place 11 hours and 30 minutes after fertilization at an average temperature of 28.2°C. Total length and weight of recently hatched larva were 2.39 ± 0.12 mm, and 0.5 ± 0.1mg respectively.

… de Ciencias Pecuarias, 2009

Brazilian Archives of Biology and Technology, 2008

This study aimed to evaluate the influence of photoperiod on juvenile suruvi (Steindachneridion s... more This study aimed to evaluate the influence of photoperiod on juvenile suruvi (Steindachneridion scriptum) in six photoperiods: 24L-0D (L= Light; D= Dark), 18L-6D, 14L-10D, 10L-14D, 6L-18D and 0L-24D. Juveniles measuring 176.8 ± 13.2mm and weighing 60.2 ± 16.0g were distributed in eighteen 150-L aquariums, stocked with 8 juveniles per aquarium. At the end of the study, treatments 24L-0D (105.7 ± 5.8g and 845.9 ±46g) and 0L-24D (93.3 ± 4.9g and 746.4 ± 39.5g) were different (P<0.05) on weight and biomass. Survival (100 ± 0.0%) and length (212.5 ±2.5mm) were the same (P>0.05) in all the treatments. The results showed that suruvi (Steindachneridion scriptum) reached better weight and biomass in extended light periods.

Acta Scientiarum. …, 2008

RESUMO. O objetivo deste estudo foi verificar a influência do fotoperíodo no cultivo de pós-larva... more RESUMO. O objetivo deste estudo foi verificar a influência do fotoperíodo no cultivo de pós-larvas de piracanjuba Brycon orbignyanus (Valenciennes, 1849) (Osteichthyes, Characidae), submetidas a quatro tratamentos: 0L-24E (L=Luz; E= Escuro), 10L-14E, 14L-10E e 24L-0E, com três 3 repetições. Pós-larvas com comprimento de 7,8±0,7mm e com peso de 3,5±0,8mg foram distribuídas em 12 aquários de 10L, estocados com 12 póslarvas por aquário. Os indivíduos foram diariamente alimentados com naúplios de Artemia, ao longo dos 10 dias de experimento. Ao final, observou-se relação positiva entre a sobrevivência e o aumento do período com luz, sendo o maior valor de sobrevivência 88,9±9,7%, obtido no tratamento com 24 horas de luminosidade, e o menor valor 58,3±8,3%, no tratamento com 24 horas em escuridão. O comprimento e peso das póslarvas de piracanjuba não apresentaram diferenças significativas (P>0,05) entre os diferentes tratamentos, porém foi observada uma maior heterogeneidade entre as pós-larvas cultivadas com maior período de escuridão.

Acta Scientiarum. Biological Sciences, 2004

The knowledge of embryonic and larvae development of fishes is a fundamental key which enables a ... more The knowledge of embryonic and larvae development of fishes is a fundamental key which enables a closer approach to their biology and taxonomy. The present study aims to characterize piracanjuba (Brycon orbignyanus) embryonic and larvae development. During the whole embryogenesis, 15 to 20 embryos were sampled and analyzed. Eggs of B. orbignyanus are semidense, transparent, spherical, and bear a large perivitelline space. Hatching takes place 18 hours and 30 minutes after fertilization at 25 ± 0.8ºC. Total length and weight of just hatched larvae were 4.46 ± 0.39mm and 2.56 ± 0.73mg, respectively. Larvae presented entirely developed and pigmented eyes, as well as a vertical mouth opening of 15.2 ± 1.9% of body length, 36 hours after hatching, period from which intense cannibalism was observed.

Brazilian Archives of Biology and Technology, 2009

The distribution and abundance of fish eggs and larvae was analyzed in three sections of the Uppe... more The distribution and abundance of fish eggs and larvae was analyzed in three sections of the Upper Uruguay river, in a stretch of 290 km. Samples were collected monthly from October, 2001 to March, 2002 during 48-h cycles at 6h intervals between each sampling. Surface and bottom samples were collected with a 0.5-mm mesh cylindroconical net. Fishes from the Upper Uruguay river were reproductively active mainly from October to January, and this activity was more intense at the Ligeiro and Chapecó tributaries and Chapecó main river. It was observed that the tributaries are important spawning grounds and larval nursery sites, indicating the importance of preserving such environments.

The distribution and abundance of fish eggs and larvae was analyzed in three sections of the Uppe... more The distribution and abundance of fish eggs and larvae was analyzed in three sections of the Upper Uruguay river,

ABSTRACT. Understanding the embryogenesis of a species is a useful tool for locating areas for sp... more ABSTRACT. Understanding the embryogenesis of a species is a useful tool for locating areas for spawning and for the study of growth of the species in their natural environment. This study was conducted at the Panamá Fish Hatchery in Santa Catarina, Brazil, to characterize the embryonic development of the piavuçu Leporinus macrocephalus (Characiformes, Anostomidae). Description was based on the analysis of embryos collected at 10-minute intervals during the first three hours after fertilization, and later at 30-minute intervals until larva hatching. Piavuçu eggs are detached, transparent, small, spherical, with a large perivitelline space. Hatching takes place 11 hours and 30 minutes after fertilization at an average temperature of 28.2°C. Total length and weight of recently hatched larva were 2.39 ± 0.12 mm, and 0.5 ± 0.1mg respectively. Key words: Leporinus macrocephalus, fish, embryonic development. RESUMO. Estadios do desenvolvimento embrionário do piavuçu Leporinus macrocephalus...

1 Introducao Dentre os metodos de coleta passiva, as armadilhas luminosas tem sido usadas na amos... more 1 Introducao Dentre os metodos de coleta passiva, as armadilhas luminosas tem sido usadas na amostragem de larvas e juvenis de peixes tanto nos ambientes marinhos como de agua doce, com seu sucesso comprovado em areas de rios, lagos, lagoas e recifes de corais. No entanto, seu uso como metodologia de coleta em ambientes aquaticos brasileiros e praticamente ausente devido a falta de estudos que avaliem sua relevância nestes ecossistemas. 2 Objetivo Avaliar a eficiencia de captura de larvas das armadilhas luminosas. 3 Metodologia O local em que foi realizado o estudo e no Medio rio Uruguai, no Municipio de Porto Lucena (RS), neste trecho o rio apresenta em torno de 1 Km de largura. Foram utilizadas 12 armadilhas cilindroconicas com malha de 500 u m. A iluminacao da armadilha foi proporcionada por uma lampada LEDs de 1 W alimentanda com bateria e fixada na parte dianteira da armadilha. Foram utilizados tres cores diferentes nas armadilhas luminosas: verde, vermelha e branca, sendo tres...

O surubim pintado Pseudoplatystoma corruscans, e uma especie tipica da Bacia do Prata com grande ... more O surubim pintado Pseudoplatystoma corruscans, e uma especie tipica da Bacia do Prata com grande relevância na pesca devido a seu excelente sabor de carne, apesar disso pouco se sabe sobre a ecologia desta especie. Devido a pressao antropica esta especie tem mostrado reducao populacional em diferentes rios do Brasil. No trecho Medio do rio Uruguai pouco se sabe sobre sua distribuicao e se esta conseguindo alcancar sucesso reprodutivo. Nesse sentido, este trabalho tem por objetivo verificar a reproducao do Pseudoplatystoma corruscans no Medio Uruguai. No estudo, foram realizadas coletas mensais de ictioplâncton entre outubro de 2015 a marco de 2016 (periodo reprodutivo), em um trecho do rio Uruguai situado no municipio de Porto Lucena-RS. Para as coletas, foram realizados arrastos utilizado rede planctonica com um formato conico-cilindrico com malha de 500 µm. Mensalmente foram realizados oito amostragens de superficie no inicio da noite. As amostras foram fixadas em formol 4% e leva...

Role of the rain and macrophytes on temporal and spatial pattern of ichthyoplankton in the Caatin... more Role of the rain and macrophytes on temporal and spatial pattern of ichthyoplankton in the Caatinga Biome, Brazil Papel da chuva e das macrófitas no padrão temporal e espacial do ictioplâncton no Bioma Caatinga, Brasil

El genero Brycon abarca 40 especies validas, algunas de estas con gran potencial zootecnico para ... more El genero Brycon abarca 40 especies validas, algunas de estas con gran potencial zootecnico para la piscicultura brasilena, entre las cuales podemos destacar el matrinxa (Brycon amazonicus), la piracanjuba (Brycon orbignyanus), la piabanha (Brycon insignis) y la piraputanga (Brycon hilarii). Dentro de los principales motivos que han despertado el interes de estas especies para la piscicultura se pueden mencionar la optima aceptacion por el mercado consumidor debido a la excelente calidad de la carne, el rapido crecimiento inicial y el habito alimenticio omnivoro con tendencia de consumo de alimentos de origen vegetal. Debido a esta caracteristica alimenticia, estas especies tienden a aceptar facilmente dietas artificiales en cautiverio, ademas de asimilar bien la proteina de origen vegetal, disminuyendo los costos de racion. Las tecnicas para la induccion al desove en cautiverio muestran resultados bastante conocidos, respondiendo bien al protocolo de induccion hormonal para la madu...

ResumenEl gOnero Brycon abarca 40 especies vAElidas, algunas de estas con gran potencial zootOcni... more ResumenEl gOnero Brycon abarca 40 especies vAElidas, algunas de estas con gran potencial zootOcnico parala piscicultura brasileaea, entre las cuales podemos destacar el matrinxa (Brycon amazonicus), lapiracanjuba (Brycon orbignyanus), la piabanha (Brycon insignis) y la piraputanga (Brycon hilarii).Dentro de los principales motivos que han despertado el interOs de estas especies para la pisciculturase pueden mencionar la optima aceptacion por el mercado consumidor debido a la excelente calidadde la carne, el rAEpido crecimiento inicial y el hAEbito alimenticio omnivoro con tendencia de consumode alimentos de origen vegetal. Debido a esta caracteristica alimenticia, estas especies tienden aaceptar fAEcilmente dietas artificiales en cautiverio, ademAEs de asimilar bien la proteina de origenvegetal, disminuyendo los costos de racion. Las tOcnicas para la induccion al desove en cautiveriomuestran resultados bastante conocidos, respondiendo bien al protocolo de induccion hormonal parala m...

EntomoBrasilis

Adult females of most black flies species (Diptera, Simuliidae) exhibit a blood-sucking habit. Im... more Adult females of most black flies species (Diptera, Simuliidae) exhibit a blood-sucking habit. Immature stages develop in water courses and are important in the ecology of lotic environments. We aim to understand the distribution of immature simuliids in the hydrographic sub-basin of the Comandaí river, in Northwest of Rio Grande do Sul, Brazil. For that purpose, simuliids were sampled in three stretches (source, intermediate and mouth) of nine streams, distributed along the three main regions of the sub-basin. Evaluations of the influence of abiotic factors in different spatial and temporal scales were made. Sampling was carried out in two seasons: between September and November 2016 (spring), and between April and July 2017 (autumn). In total, 17,146 individuals were sampled (larvae of last instars and pupae), which resulted in the identification of eleven Simuliidae species. The most abundant species were Simulium pertinax Kollar (77.55%), followed by Simulium incrustatum Lutz (1...

EntomoBrasilis

In southern Brazil there are several problems regarding the hematophageal activity of black flies... more In southern Brazil there are several problems regarding the hematophageal activity of black flies, and the information on the distribution of species are still insufficient. In this study, our main goals were to recognize Simuliidae species and to analyze abiotic factors regarding the distribution of immature stages (larva and pupa) in streams from the Ijuí River basin, Northwest of Rio Grande do Sul, Brazil. We sampled simulids specimens in 27 study sites, covering three regions (high, intermediate and low altitude). Concomitantly, we recorded abiotic factors in the studied sites, such as: temperature, electrical conductivity, dissolved oxygen, atmospheric pressure, pH, altitude and stream width. For data analysis, we performed Kruskal-Wallis, ANOVA, Principal Component Analysis (PCA), Analysis of Indicator Species and Canonical Correspondence (CCA). A total of 10 species of black Flies was recorded. Simulium pertinax Kollar, Simulium incrustatum Lutz and Simulium orbitale Lutz were the most frequent. There was no significant difference in richness and density of the species between the different regions studied, except for Simulium jujuyense Paterson & Shannon. The sampled environments were segregated according to the location within the basin, and only S. jujuyense was considered an indicator species of the upper region. These results can be explained by the homogeneous conditions of the Ijuí River basin, which have suffered anthropogenic pressure mainly due to agricultural activities, resulting in losses in local aquatic biodiversity. Also, it may indicate that the control must be conducted considering the basin as a whole, and not only as isolated stretches of the streams.

Acta Scientiarum. Animal Sciences, 2008

Understanding the embryogenesis of a species is a useful tool for locating areas for spawning and... more Understanding the embryogenesis of a species is a useful tool for locating areas for spawning and for the study of growth of the species in their natural environment. This study was conducted at the Panamá Fish Hatchery in Santa Catarina, Brazil, to characterize the embryonic development of the piavuçu Leporinus macrocephalus (Characiformes, Anostomidae). Description was based on the analysis of embryos collected at 10-minute intervals during the first three hours after fertilization, and later at 30-minute intervals until larva hatching. Piavuçu eggs are detached, transparent, small, spherical, with a large perivitelline space. Hatching takes place 11 hours and 30 minutes after fertilization at an average temperature of 28.2°C. Total length and weight of recently hatched larva were 2.39 ± 0.12 mm, and 0.5 ± 0.1mg respectively.

… de Ciencias Pecuarias, 2009

Brazilian Archives of Biology and Technology, 2008

This study aimed to evaluate the influence of photoperiod on juvenile suruvi (Steindachneridion s... more This study aimed to evaluate the influence of photoperiod on juvenile suruvi (Steindachneridion scriptum) in six photoperiods: 24L-0D (L= Light; D= Dark), 18L-6D, 14L-10D, 10L-14D, 6L-18D and 0L-24D. Juveniles measuring 176.8 ± 13.2mm and weighing 60.2 ± 16.0g were distributed in eighteen 150-L aquariums, stocked with 8 juveniles per aquarium. At the end of the study, treatments 24L-0D (105.7 ± 5.8g and 845.9 ±46g) and 0L-24D (93.3 ± 4.9g and 746.4 ± 39.5g) were different (P<0.05) on weight and biomass. Survival (100 ± 0.0%) and length (212.5 ±2.5mm) were the same (P>0.05) in all the treatments. The results showed that suruvi (Steindachneridion scriptum) reached better weight and biomass in extended light periods.

Acta Scientiarum. …, 2008

RESUMO. O objetivo deste estudo foi verificar a influência do fotoperíodo no cultivo de pós-larva... more RESUMO. O objetivo deste estudo foi verificar a influência do fotoperíodo no cultivo de pós-larvas de piracanjuba Brycon orbignyanus (Valenciennes, 1849) (Osteichthyes, Characidae), submetidas a quatro tratamentos: 0L-24E (L=Luz; E= Escuro), 10L-14E, 14L-10E e 24L-0E, com três 3 repetições. Pós-larvas com comprimento de 7,8±0,7mm e com peso de 3,5±0,8mg foram distribuídas em 12 aquários de 10L, estocados com 12 póslarvas por aquário. Os indivíduos foram diariamente alimentados com naúplios de Artemia, ao longo dos 10 dias de experimento. Ao final, observou-se relação positiva entre a sobrevivência e o aumento do período com luz, sendo o maior valor de sobrevivência 88,9±9,7%, obtido no tratamento com 24 horas de luminosidade, e o menor valor 58,3±8,3%, no tratamento com 24 horas em escuridão. O comprimento e peso das póslarvas de piracanjuba não apresentaram diferenças significativas (P>0,05) entre os diferentes tratamentos, porém foi observada uma maior heterogeneidade entre as pós-larvas cultivadas com maior período de escuridão.

Acta Scientiarum. Biological Sciences, 2004

The knowledge of embryonic and larvae development of fishes is a fundamental key which enables a ... more The knowledge of embryonic and larvae development of fishes is a fundamental key which enables a closer approach to their biology and taxonomy. The present study aims to characterize piracanjuba (Brycon orbignyanus) embryonic and larvae development. During the whole embryogenesis, 15 to 20 embryos were sampled and analyzed. Eggs of B. orbignyanus are semidense, transparent, spherical, and bear a large perivitelline space. Hatching takes place 18 hours and 30 minutes after fertilization at 25 ± 0.8ºC. Total length and weight of just hatched larvae were 4.46 ± 0.39mm and 2.56 ± 0.73mg, respectively. Larvae presented entirely developed and pigmented eyes, as well as a vertical mouth opening of 15.2 ± 1.9% of body length, 36 hours after hatching, period from which intense cannibalism was observed.

Brazilian Archives of Biology and Technology, 2009

The distribution and abundance of fish eggs and larvae was analyzed in three sections of the Uppe... more The distribution and abundance of fish eggs and larvae was analyzed in three sections of the Upper Uruguay river, in a stretch of 290 km. Samples were collected monthly from October, 2001 to March, 2002 during 48-h cycles at 6h intervals between each sampling. Surface and bottom samples were collected with a 0.5-mm mesh cylindroconical net. Fishes from the Upper Uruguay river were reproductively active mainly from October to January, and this activity was more intense at the Ligeiro and Chapecó tributaries and Chapecó main river. It was observed that the tributaries are important spawning grounds and larval nursery sites, indicating the importance of preserving such environments.