RESUMO

After the formation of Itaipu Reservoir, the invader Trachelyopterus galeatus colonized the upper Paraná River. Light microscopy was used to describe gametogenesis and the reproductive phases of females and males. The following data were verified: diameter of the oocytes, spawning type, batch fecundity by ovary weight, standard length, and total weight of the fish, along with the regions where this species reproduced in the upper Paraná River floodplain. A total of 470 specimens were collected quarterly in 2016, 2018 and 2019, and bimonthly in 2017. The gonads were fixed in a Karnovsky solution, dehydrated, infiltrated, and embedded in historesin. The histological slides were stained using PAS + iron hematoxylin + metanil yellow, analyzed and photographed under an image-capturing microscope. As regards diameter of the oocytes and fecundity estimates, ovaries whose oocytes were measured under a stereomicroscope were sampled. In the oogenesis, undifferentiated and differentiated oogonia, early primary growth oocytes, secondary growth oocytes, full-grown oocytes and maturing oocytes were recorded. In the spermatogenesis, primary and secondary spermatogonia, primary and secondary spermatocytes, spermatids and spermatozoa were recorded. The reproductive phases found for females and males were: immature, early development, late development, spawning/sperm-releasing capable, regression, and regeneration. Trachelyopterus galeatus prefers to occupy and reproduce in the Ventura, Patos, Guaraná, Fechada, Garças, and Pau Véio lagoons. The diameter of the oocytes varied from 0.4 to 2.9 mm. Females spawn, on average, 113 oocytes per batch. Batch fecundity variation shows that the larger the ovary, standard length, and total weight, the larger the number of oocytes to be spawned. This invader possesses reproductive success in the upper Paraná River floodplain, especially in lagoons.(AU)

Assuntos

RESUMO

After the formation of Itaipu Reservoir, the invader Trachelyopterus galeatus colonized the upper Paraná River. Light microscopy was used to describe gametogenesis and the reproductive phases of females and males. The following data were verified: diameter of the oocytes, spawning type, batch fecundity by ovary weight, standard length, and total weight of the fish, along with the regions where this species reproduced in the upper Paraná River floodplain. A total of 470 specimens were collected quarterly in 2016, 2018 and 2019, and bimonthly in 2017. The gonads were fixed in a Karnovsky solution, dehydrated, infiltrated, and embedded in historesin. The histological slides were stained using PAS + iron hematoxylin + metanil yellow, analyzed and photographed under an image-capturing microscope. As regards diameter of the oocytes and fecundity estimates, ovaries whose oocytes were measured under a stereomicroscope were sampled. In the oogenesis, undifferentiated and differentiated oogonia, early primary growth oocytes, secondary growth oocytes, full-grown oocytes and maturing oocytes were recorded. In the spermatogenesis, primary and secondary spermatogonia, primary and secondary spermatocytes, spermatids and spermatozoa were recorded. The reproductive phases found for females and males were: immature, early development, late development, spawning/sperm-releasing capable, regression, and regeneration. Trachelyopterus galeatus prefers to occupy and reproduce in the Ventura, Patos, Guaraná, Fechada, Garças, and Pau Véio lagoons. The diameter of the oocytes varied from 0.4 to 2.9 mm. Females spawn, on average, 113 oocytes per batch. Batch fecundity variation shows that the larger the ovary, standard length, and total weight, the larger the number of oocytes to be spawned. This invader possesses reproductive success in the upper Paraná River floodplain, especially in lagoons.

Assuntos

RESUMO

SummaryThe aim of this study was to describe the effect of temperature on the fertilization, early developmental stages, and survival rate of two Neotropical catfishes Pimelodus maculatus and Pseudopimelodus mangurus. After fertilization, the eggs were incubated at 22°C, 26°C, and 30°C, which resulted in fertilization rates of 96.95 ± 1.79%, 98.74 ± 0.76%, and 98.44 ± 0.19% for P. maculatus and 96.10 ± 1.58%, 98.00 ± 0.63%, and 94.60 ± 2.09% for P. mangurus, respectively. For P. maculatus, hatching occurred after 22 h 30 min post-fertilization at 22°C, 16 h 30 min at 26°C, and 11 h 20 min at 30°C, and the hatching rates were 43.87 ± 7,46%, 57.57 ± 17.49%, and 53.63 ± 16.27%, respectively. For P. mangurus, hatching occurred after 28 h 30 min post-fertilization at 22°C and 17 h 30 min at 26°C with respective hatching rates of 45.4 ± 21.02% and 68.1 ± 12.67%. For this species, all embryos incubated at 30°C died before hatching. Additionally, for P. maculatus, the larvae from the lower (22°C) and higher temperatures (30°C) presented increased abnormality rates, as observed in the head, tail and yolk regions. The lowest abnormality rate was detected at 26°C, which was considered the optimal incubation temperature for both species. The developed protocol enables the manipulation of embryonic development, which is important for the application of reproductive biotechniques, including chimerism and chromosome-set manipulation. The data obtained here are also important for the surrogate propagation of this species as P. mangurus was recently categorized as an endangered fish species.

Assuntos

RESUMO

Ariids such as Genidens genidens are particularly susceptible to overfishing because of their complex reproductive mechanisms, which result in slow replenishment of stocks. In this study, we obtained data about the reproductive ecology of the catfish G. genidens in the Guanabara Bay estuary, Rio de Janeiro, Brazil, providing supporting information for management of its fishery. The sex ratio, mean size of each sex at first sexual maturation, and female fecundity were determined and the reproductive period was characterized. The males:females ratio was 1:2. The fecundity is low and increases proportionally to the females' growth in total length and weight. The breeding season occurs during the warmest months of the year, with spawning extending from October through March and incubation from December through April. Sexual maturation is late, with males maturing at a larger size than females. Skipping spawning was also identified in females. Based on the reproductive biology, it is suggested that the catch be restricted to individuals larger than 20 cm, considering the L75 of the males, and that fishing be prohibited from December through March, to include the main period of spawning season by females and oropharyngeal incubation by males.(AU)

Ariídeos, como Genidens genidens, são particularmente suscetíveis à sobrepesca devido a seus complexos mecanismos reprodutivos, que resultam em uma reposição lenta dos estoques. Neste estudo, obtivemos dados sobre a ecologia reprodutiva do bagre G. genidens no estuário da Baía de Guanabara, Rio de Janeiro, Brasil, fornecendo subsídios para seu manejo pesqueiro. A proporção sexual, o tamanho médio de primeira maturação sexual de cada sexo e a fecundidade das fêmeas foram determinados e o período reprodutivo caracterizado. A proporção machos:fêmeas foi de ١:2. A fecundidade é baixa e aumenta proporcionalmente ao crescimento das fêmeas em comprimento total e no peso. O período reprodutivo ocorre durante os meses mais quentes do ano, com a desova se estendendo de outubro a março e a incubação de dezembro a abril. A maturação sexual é tardia, com machos amadurecendo em tamanho maior que as fêmeas. Também foi identificado nas fêmeas adiamento da desova. Com base na biologia reprodutiva, sugere-se que a captura seja restrita a indivíduos maiores que 20 cm, considerando a C75 dos machos, e que a pesca seja proibida de dezembro a março, para incluir o período principal de época de desova das fêmeas e incubação orofaríngea dos machos.(AU)

Assuntos

RESUMO

Samples of eggs, newly hatched larvae (NHL), and larvae at the end of the lecithotrophic period (eight days after hatching) (LPL) of Lophiosilurus alexandri were collected to determine the amino acid and fatty acid profiles. Crude protein did not change throughout initial development and the concentration of lipids was highest in NHL. The content of the indispensable amino acids (IAA) isoleucine, leucine, and valine decreased in LPL, while in eggs and NHL they remained high and similar in value. The dispensable amino acids (DAA), such as aspartic acid, tyrosine, and glycine, increased in LPL, while alanine decreased. The percentage of neutral lipids increased in LPL. The saturated fatty acid content decreased during ontogeny, while monounsaturated fatty acids decreased only in LPL. The polyunsaturated fatty acid content was highest in LP. Polar fatty acids were found in higher percentages in eggs and NHL, but lower in LPL. Saturated fatty acid content decreased during ontogenetic development, while that of monounsaturated fatty acids decreased only in LPL. Polyunsaturated fatty acid content was highest in LPL. Protein content was maintained during ontogenetic development, while amino acid classes experienced changes. Lophiosilurus alexandri preferentially uses saturated and monosaturated fatty acids as an energy source during its early development.(AU)

Amostras de ovos, larvas recém-eclodidas (NHL) e larvas no final do período lecitotrófico (oito dias após a incubação) (LPL) de Lophiosilurus alexandri foram coletadas para determinar os perfis de aminoácidos e ácidos graxos. A proteína bruta não alterou durante o desenvolvimento inicial e a concentração de lipídios foi maior na NHL. O conteúdo dos aminoácidos indispensáveis (IAA) isoleucina, leucina e valina diminuíram em LPL, enquanto nos ovos e NHL eles permaneceram com valores elevados e semelhantes entre si. Os aminoácidos dispensáveis (DAA), como ácido aspártico, tirosina e glicina, aumentaram em LPL, enquanto a alanina diminuiu. A porcentagem de lipídios neutros aumentou em LPL. O teor de ácidos graxos saturados diminuiu durante a ontogenia, enquanto os ácidos graxos monoinsaturados diminuíram apenas em LPL. O teor de ácidos graxos poliinsaturados foi maior em LPL. Os ácidos graxos polares foram encontrados em porcentagens mais altas em ovos e NHL, e menores em LPL. O teor de ácidos graxos saturados reduziu durante o desenvolvimento ontogenético, enquanto que os ácidos graxos monoinsaturados diminuíram apenas em LPL. O teor de ácidos graxos poliinsaturados foi maior em LPL. O conteúdo de proteínas foi mantido durante o desenvolvimento ontogenético, enquanto as classes de aminoácidos sofreram mudanças. Lophiosilurus alexandri usa preferencialmente ácidos graxos saturados e monossaturados como fonte de energia durante o desenvolvimento inicial.(AU)

Assuntos

RESUMO

Ariids such as Genidens genidens are particularly susceptible to overfishing because of their complex reproductive mechanisms, which result in slow replenishment of stocks. In this study, we obtained data about the reproductive ecology of the catfish G. genidens in the Guanabara Bay estuary, Rio de Janeiro, Brazil, providing supporting information for management of its fishery. The sex ratio, mean size of each sex at first sexual maturation, and female fecundity were determined and the reproductive period was characterized. The males:females ratio was 1:2. The fecundity is low and increases proportionally to the females' growth in total length and weight. The breeding season occurs during the warmest months of the year, with spawning extending from October through March and incubation from December through April. Sexual maturation is late, with males maturing at a larger size than females. Skipping spawning was also identified in females. Based on the reproductive biology, it is suggested that the catch be restricted to individuals larger than 20 cm, considering the L75 of the males, and that fishing be prohibited from December through March, to include the main period of spawning season by females and oropharyngeal incubation by males.(AU)

Ariídeos, como Genidens genidens, são particularmente suscetíveis à sobrepesca devido a seus complexos mecanismos reprodutivos, que resultam em uma reposição lenta dos estoques. Neste estudo, obtivemos dados sobre a ecologia reprodutiva do bagre G. genidens no estuário da Baía de Guanabara, Rio de Janeiro, Brasil, fornecendo subsídios para seu manejo pesqueiro. A proporção sexual, o tamanho médio de primeira maturação sexual de cada sexo e a fecundidade das fêmeas foram determinados e o período reprodutivo caracterizado. A proporção machos:fêmeas foi de ١:2. A fecundidade é baixa e aumenta proporcionalmente ao crescimento das fêmeas em comprimento total e no peso. O período reprodutivo ocorre durante os meses mais quentes do ano, com a desova se estendendo de outubro a março e a incubação de dezembro a abril. A maturação sexual é tardia, com machos amadurecendo em tamanho maior que as fêmeas. Também foi identificado nas fêmeas adiamento da desova. Com base na biologia reprodutiva, sugere-se que a captura seja restrita a indivíduos maiores que 20 cm, considerando a C75 dos machos, e que a pesca seja proibida de dezembro a março, para incluir o período principal de época de desova das fêmeas e incubação orofaríngea dos machos.(AU)

Assuntos

RESUMO

Samples of eggs, newly hatched larvae (NHL), and larvae at the end of the lecithotrophic period (eight days after hatching) (LPL) of Lophiosilurus alexandri were collected to determine the amino acid and fatty acid profiles. Crude protein did not change throughout initial development and the concentration of lipids was highest in NHL. The content of the indispensable amino acids (IAA) isoleucine, leucine, and valine decreased in LPL, while in eggs and NHL they remained high and similar in value. The dispensable amino acids (DAA), such as aspartic acid, tyrosine, and glycine, increased in LPL, while alanine decreased. The percentage of neutral lipids increased in LPL. The saturated fatty acid content decreased during ontogeny, while monounsaturated fatty acids decreased only in LPL. The polyunsaturated fatty acid content was highest in LP. Polar fatty acids were found in higher percentages in eggs and NHL, but lower in LPL. Saturated fatty acid content decreased during ontogenetic development, while that of monounsaturated fatty acids decreased only in LPL. Polyunsaturated fatty acid content was highest in LPL. Protein content was maintained during ontogenetic development, while amino acid classes experienced changes. Lophiosilurus alexandri preferentially uses saturated and monosaturated fatty acids as an energy source during its early development.(AU)

Amostras de ovos, larvas recém-eclodidas (NHL) e larvas no final do período lecitotrófico (oito dias após a incubação) (LPL) de Lophiosilurus alexandri foram coletadas para determinar os perfis de aminoácidos e ácidos graxos. A proteína bruta não alterou durante o desenvolvimento inicial e a concentração de lipídios foi maior na NHL. O conteúdo dos aminoácidos indispensáveis (IAA) isoleucina, leucina e valina diminuíram em LPL, enquanto nos ovos e NHL eles permaneceram com valores elevados e semelhantes entre si. Os aminoácidos dispensáveis (DAA), como ácido aspártico, tirosina e glicina, aumentaram em LPL, enquanto a alanina diminuiu. A porcentagem de lipídios neutros aumentou em LPL. O teor de ácidos graxos saturados diminuiu durante a ontogenia, enquanto os ácidos graxos monoinsaturados diminuíram apenas em LPL. O teor de ácidos graxos poliinsaturados foi maior em LPL. Os ácidos graxos polares foram encontrados em porcentagens mais altas em ovos e NHL, e menores em LPL. O teor de ácidos graxos saturados reduziu durante o desenvolvimento ontogenético, enquanto que os ácidos graxos monoinsaturados diminuíram apenas em LPL. O teor de ácidos graxos poliinsaturados foi maior em LPL. O conteúdo de proteínas foi mantido durante o desenvolvimento ontogenético, enquanto as classes de aminoácidos sofreram mudanças. Lophiosilurus alexandri usa preferencialmente ácidos graxos saturados e monossaturados como fonte de energia durante o desenvolvimento inicial.(AU)

Assuntos

RESUMO

The aim of this study was to remove the adhesiveness of Pseudoplatystoma fasciatum eggs using solutions of urea for 10, 30, 60 and 90 min (treatments T0-T3) or, in urea for 10 min and washed in tannin (T4). In the control group, eggs were kept in water. After two experiments, we observed that eggs of control group presented the best embryo viability rates, even maintaining egg adhesiveness, being better than the other treatments. The T4, had the worst embryo viability rates. We observed that embryos of the T4 treatment presented reduced growth and formed a separate group when analyzing morphological parameters (egg diameter, total egg area, embryo area and yolk sac area) by multivariate analysis. Concluding, the control group, free of chemicals, provided the best results and is considered the best alternative for the immediate conservation and aquaculture production of P. fasciatum.(AU)

O objetivo deste estudo foi neutralizar a adesividade de ovos de Pseudoplatystoma fasciatum a partir da utilização de soluções de ureia por 10, 30, 60 ou 90 min (tratamentos T0-T3) ou em ureia por 10 min e lavados em tanino (T4). No controle, os ovos foram mantidos apenas em água. Após dois experimentos realizados, no grupo controle foram observadas as melhores taxas de viabilidade embrionária, mesmo mantendo a adesividade dos ovos, sendo melhor que os demais tratamentos. No T4 foram verificadas as piores taxas de viabilidade embrionária. Foi observado que os embriões do tratamento T4 apresentaram crescimento reduzido e formaram um grupo separado após análise dos parâmetros morfológicos (diâmetro do ovo, área total do ovo, área do embrião e área do saco vitelínico) por análise multivariada. Concluiu-se que o grupo controle, livre de produtos químicos, proporcionou os melhores resultados, sendo considerado a melhor alternativa para a conservação imediata e produção aquícola de P. fasciatum.(AU)

Assuntos

RESUMO

The aim of this study was to remove the adhesiveness of Pseudoplatystoma fasciatum eggs using solutions of urea for 10, 30, 60 and 90 min (treatments T0-T3) or, in urea for 10 min and washed in tannin (T4). In the control group, eggs were kept in water. After two experiments, we observed that eggs of control group presented the best embryo viability rates, even maintaining egg adhesiveness, being better than the other treatments. The T4, had the worst embryo viability rates. We observed that embryos of the T4 treatment presented reduced growth and formed a separate group when analyzing morphological parameters (egg diameter, total egg area, embryo area and yolk sac area) by multivariate analysis. Concluding, the control group, free of chemicals, provided the best results and is considered the best alternative for the immediate conservation and aquaculture production of P. fasciatum.

O objetivo deste estudo foi neutralizar a adesividade de ovos de Pseudoplatystoma fasciatum a partir da utilização de soluções de ureia por 10, 30, 60 ou 90 min (tratamentos T0-T3) ou em ureia por 10 min e lavados em tanino (T4). No controle, os ovos foram mantidos apenas em água. Após dois experimentos realizados, no grupo controle foram observadas as melhores taxas de viabilidade embrionária, mesmo mantendo a adesividade dos ovos, sendo melhor que os demais tratamentos. No T4 foram verificadas as piores taxas de viabilidade embrionária. Foi observado que os embriões do tratamento T4 apresentaram crescimento reduzido e formaram um grupo separado após análise dos parâmetros morfológicos (diâmetro do ovo, área total do ovo, área do embrião e área do saco vitelínico) por análise multivariada. Concluiu-se que o grupo controle, livre de produtos químicos, proporcionou os melhores resultados, sendo considerado a melhor alternativa para a conservação imediata e produção aquícola de P. fasciatum.

Assuntos

RESUMO

The aim of this study was to characterize the embryonic development of Zungaro jahu, a fresh water teleostei commonly known as 'jaú'. Samples were collected at pre-determined times from oocyte release to larval hatching and analysed under light microscopy, transmission electron microscopy and scanning electron microscopy. At the first collection times, the oocytes and eggs were spherical and yellowish, with an evident micropyle. Embryo development took place at 29.4 ± 1.5°C and was divided into seven stages: zygote, cleavage, morula, blastula, gastrula, organogenesis, and hatching. The differentiation of the animal and vegetative poles occured during the zygote stage, at 10 min post-fertilization (mpf), leading to the development of the egg cell at 15 mpf. From 20 to 75 mpf, successive cleavages resulted in the formation of 2, 4, 8, 16, 32 and 64 blastomeres. The morula stage was observed between 90 and 105 mpf, and the blastula and gastrula stage at 120 and 180 mpf; respectively. The end of the gastrula stage was characterized by the presence of the yolk plug at 360 mpf. Organogenesis followed, with differentiation of the cephalic and caudal regions, elongation of the embryo by the cephalo-caudal axis, and somitogenesis. Hatching occurred at 780 mpf, with mean larval total length of 3.79 ± 0.11 mm.

Assuntos

RESUMO

The objective of this study was to evaluate the effect of copper-contaminated water on sperm motility, fertilization, and embryonic and larval development of silver catfish (Rhamdia quelen). A randomized experimental design with five treatments and four replicates was used. Two experiments were carried out: (1) controlled fertilization was performed under different levels of copper contamination and egg hatching was performed in clean water; and (2) copper-contaminated water was used for both fertilization and hatching assays. The time of sperm motility and sperm motility rates linearly decreased with increasing copper concentration in the water. Fertilization and hatching rates were also affected when the concentrations of copper in the water were above 0.0979 mg Cu+2 L-1 and 0.0331 mg Cu+2 L-1, respectively. Gamete exposure to levels between 15 mg Cu+2 L-1 and 60 mg Cu+2 L-1 for short periods of time negatively affected sperm motility, oocyte fertilization, and egg hatching rates. In addition, when gametes and embryos were exposed at levels above 0.03 mg Cu+2 L-1 during long periods of time, egg hatching rates were reduced, and at levels between 0.05 mg Cu+2 L-1 and 0.20 mg Cu+2 L-1 the number of abnormal larvae increased.(AU)

O objetivo deste estudo foi avaliar o efeito da água contaminada de cobre na motilidade espermática, fertilização e desenvolvimento embrionário e larval de jundiá (Rhamdia quelen). O delineamento experimental foi inteiramente casualizado, com cinco tratamentos e quatro repetições. Dois ensaios foram conduzidos: (1) a fertilização controlada foi realizada com diferentes níveis de água contaminada com cobre e a incubação do ovo realizada em água limpa; e (2) a contaminação da água foi utilizada tanto na fertilização e quanto na incubação dos ovos. O tempo de motilidade de espermatozóides e as taxas de motilidade do esperma foram reduzidas com o aumento da concentração de cobre na água. As taxas de fertilização e eclosão também foram afetados quando as concentrações de cobre na água estavam acima de 0,0979 mg Cu+2 L-1 e 0,0331 mg Cu+2 L-1, respectivamente. A exposição dos gametas por um curto período de tempo em níveis entre 15 ou 60 mg de Cu+2 L-1 promoveu danos sobre a motilidade dos espermatozóides, a fertilização de oócitos e a eclosão dos ovos. Além disso, quando os gametas e embriões foram expostos a níveis acima de 0,03 mg de Cu+2 L-1 por um longo período de tempo, a eclosão dos ovos foi reduzida, e em níveis de 0,05 a 0.20mg Cu+2 L-1 o anormalidade larval aumentou.(AU)

Assuntos

RESUMO

The objective of this study was to evaluate the effect of copper-contaminated water on sperm motility, fertilization, and embryonic and larval development of silver catfish (Rhamdia quelen). A randomized experimental design with five treatments and four replicates was used. Two experiments were carried out: (1) controlled fertilization was performed under different levels of copper contamination and egg hatching was performed in clean water; and (2) copper-contaminated water was used for both fertilization and hatching assays. The time of sperm motility and sperm motility rates linearly decreased with increasing copper concentration in the water. Fertilization and hatching rates were also affected when the concentrations of copper in the water were above 0.0979 mg Cu+2 L-1 and 0.0331 mg Cu+2 L-1, respectively. Gamete exposure to levels between 15 mg Cu+2 L-1 and 60 mg Cu+2 L-1 for short periods of time negatively affected sperm motility, oocyte fertilization, and egg hatching rates. In addition, when gametes and embryos were exposed at levels above 0.03 mg Cu+2 L-1 during long periods of time, egg hatching rates were reduced, and at levels between 0.05 mg Cu+2 L-1 and 0.20 mg Cu+2 L-1 the number of abnormal larvae increased.

O objetivo deste estudo foi avaliar o efeito da água contaminada de cobre na motilidade espermática, fertilização e desenvolvimento embrionário e larval de jundiá (Rhamdia quelen). O delineamento experimental foi inteiramente casualizado, com cinco tratamentos e quatro repetições. Dois ensaios foram conduzidos: (1) a fertilização controlada foi realizada com diferentes níveis de água contaminada com cobre e a incubação do ovo realizada em água limpa; e (2) a contaminação da água foi utilizada tanto na fertilização e quanto na incubação dos ovos. O tempo de motilidade de espermatozóides e as taxas de motilidade do esperma foram reduzidas com o aumento da concentração de cobre na água. As taxas de fertilização e eclosão também foram afetados quando as concentrações de cobre na água estavam acima de 0,0979 mg Cu+2 L-1 e 0,0331 mg Cu+2 L-1, respectivamente. A exposição dos gametas por um curto período de tempo em níveis entre 15 ou 60 mg de Cu+2 L-1 promoveu danos sobre a motilidade dos espermatozóides, a fertilização de oócitos e a eclosão dos ovos. Além disso, quando os gametas e embriões foram expostos a níveis acima de 0,03 mg de Cu+2 L-1 por um longo período de tempo, a eclosão dos ovos foi reduzida, e em níveis de 0,05 a 0.20mg Cu+2 L-1 o anormalidade larval aumentou.

Assuntos

RESUMO

This study described the initial development of Pseudoplatystoma reticulatum, as well as changes in growth patterns. Morphometric and meristic variables were analyzed during embryonic, larval and juvenile periods, even as allometric growth coefficients for larvae and juveniles. Eggs showed an average diameter of 1.79 mm and broad perivitelline space (23.41%). The total length (TL) of the larvae ranged from 3.05 to 25.72 mm, and the total number of myomeres ranged from 45 to 50 (preanal = 13-16 and postanal = 30-35). Initial pigmentation is poor, concentrated at the extremities of the yolk sac. In the flexion stage, the pigmentation intensifies and forms a longitudinal stripe extending from the snout to the operculum and two longitudinal stripes on the body, one dorsal and the other ventral, that unite at the caudal peduncle. At first, there is a differential growth of the head and tail, and then there is the growth of the body, which shows changes in the ontogenetic priorities of feeding, swimming, and breathing capacities. Our results are very important for ecology, systematics, and hatchering, especially in terms of ontogenetic variation in morphology, growth, feeding, behavior, and mortality of P. reticulatum.

Este estudo descreveu o desenvolvimento inicial de Pseudoplatystoma reticulatum, bem como as mudanças nos padrões de crescimento, testando a hipótese da ocorrência de crescimento diferencial durante a ontogenia inicial da espécie. Variáveis morfométricas e merísticas foram analisadas durante os períodos embrionário, larval e juvenil, assim como os coeficientes de crescimento alométrico para larvas e juvenis. Os ovos apresentaram diâmetro médio de 1,79 mm e espaço perivitelino amplo (23,41%). O comprimento total (CT) das larvas variou de 3,05 a 125,72 mm e o número total de miômeros de 45 a 50 (pré-anal=13-16 e pós-anal=30-35). A pigmentação inicial é escassa, concentrada nas extremidades do saco vitelino. A partir do estágio de flexão a pigmentação se intensifica, formando uma faixa longitudinal que se estende do focinho ao opérculo e duas no corpo, uma dorsal e outra ventral, que se unem no pedúnculo caudal. Inicialmente há um crescimento diferenciado da cabeça e da cauda, com posterior crescimento do tronco, que demonstra mudanças nas prioridades ontogenéticas para as capacidades de alimentação, natação e respiração. Nossos resultados são de grande importância para a ecologia, sistemática e larvicultura, especialmente em termos de variação ontogenética na morfologia, crescimento, alimentação, comportamento e mortalidade P. reticulatum.

Assuntos

RESUMO

This study described the initial development of Pseudoplatystoma reticulatum, as well as changes in growth patterns. Morphometric and meristic variables were analyzed during embryonic, larval and juvenile periods, even as allometric growth coefficients for larvae and juveniles. Eggs showed an average diameter of 1.79 mm and broad perivitelline space (23.41%). The total length (TL) of the larvae ranged from 3.05 to 25.72 mm, and the total number of myomeres ranged from 45 to 50 (preanal = 13-16 and postanal = 30-35). Initial pigmentation is poor, concentrated at the extremities of the yolk sac. In the flexion stage, the pigmentation intensifies and forms a longitudinal stripe extending from the snout to the operculum and two longitudinal stripes on the body, one dorsal and the other ventral, that unite at the caudal peduncle. At first, there is a differential growth of the head and tail, and then there is the growth of the body, which shows changes in the ontogenetic priorities of feeding, swimming, and breathing capacities. Our results are very important for ecology, systematics, and hatchering, especially in terms of ontogenetic variation in morphology, growth, feeding, behavior, and mortality of P. reticulatum.(AU)

Este estudo descreveu o desenvolvimento inicial de Pseudoplatystoma reticulatum, bem como as mudanças nos padrões de crescimento, testando a hipótese da ocorrência de crescimento diferencial durante a ontogenia inicial da espécie. Variáveis morfométricas e merísticas foram analisadas durante os períodos embrionário, larval e juvenil, assim como os coeficientes de crescimento alométrico para larvas e juvenis. Os ovos apresentaram diâmetro médio de 1,79 mm e espaço perivitelino amplo (23,41%). O comprimento total (CT) das larvas variou de 3,05 a 125,72 mm e o número total de miômeros de 45 a 50 (pré-anal=13-16 e pós-anal=30-35). A pigmentação inicial é escassa, concentrada nas extremidades do saco vitelino. A partir do estágio de flexão a pigmentação se intensifica, formando uma faixa longitudinal que se estende do focinho ao opérculo e duas no corpo, uma dorsal e outra ventral, que se unem no pedúnculo caudal. Inicialmente há um crescimento diferenciado da cabeça e da cauda, com posterior crescimento do tronco, que demonstra mudanças nas prioridades ontogenéticas para as capacidades de alimentação, natação e respiração. Nossos resultados são de grande importância para a ecologia, sistemática e larvicultura, especialmente em termos de variação ontogenética na morfologia, crescimento, alimentação, comportamento e mortalidade P. reticulatum.(AU)

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The aim of this study was to identify and characterize pituitary cells of Steindachneridion parahybae females in captivity, highlighting the possible relationship with reproductive disorders at this level, since this species shows oocyte final maturation, ovulation and spawning dysfunction in captivity. The localization and distribution of growth hormone (GH), prolactin (PRL), somatolactin (SL), ß-luteinizing hormone (ß-LH), and ß-follicle stimulating hormone (ß-FSH) immunoreactive (-ir) cells in the adenohypophysis was studied by immunohistochemical and Western blot methods. In addition, cellular morphometric analyses and semi-quantification of ir-cells optical density (OD) during the annual reproductive cycle and after artificial induced spawning (AIS) were performed. Results showed that the distribution and general localization of pituitary cell types were similar to that of other teleost species. However, the morphometrical study of adenohypophysial cells showed differences along the reproductive cycle and following AIS. In general, females at the vitellogenic stage presented greater OD values for GH, PRL and SL than at other maturation stages (previtellogenic and regression stages), probably indicating an increased cellular activity during this stage. Conversely, ß-LH OD did not vary during the annual reproductive cycle. After AIS, ß-LH, SL and GH ir-cells showed an increase in OD values suggesting a possible involvement on oocyte final maturation, ovulation and spawning or a feedback control on the brain-pituitary-gonads axis. Reproductive dysfunction in S. parahybae females in captivity may be due to alteration of the synthesis pathways of ß-LH. In addition, GH family of hormones could modulate associated mechanisms that influence the reproductive status in this species.

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A tolerância de peixes de água doce à salinidade e os níveis adequados de náuplios de Artemia na alimentação durante a larvicultura são de extrema importância para a padronização dos manejos em ambientes de criação intensiva. Dessa forma, o objetivo do trabalho foi estimar a salinidade letal (SL50) para larvas de jundiá Rhamdia quelen e determinar o efeito da salinidade e da concentração de presas vivas na larvicultura intensiva. No primeiro ensaio, larvas ao final do período lecitotrófico (1,1±0,8mg) foram submetidas às salinidades de 0, 2, 4, 6, 8, 10, 15 e 20g de sal/L por um período de 96h. No segundo experimento, as larvas de jundiá, no início da alimentação exógena (1,2±0,3mg), foram submetidas a três salinidades (água doce 0, 2 e 4g de sal/L) e três concentrações de presas vivas (início: 300, 500, 700 náuplios de Artemia/larvas/dia, sendo esse montante aumentado a cada cinco dias). O experimento foi realizado em delineamento inteiramente ao acaso, em esquema fatorial 3x3, por um período de 15 dias. No experimento 1, as larvas de jundiá submetidas às salinidades de 10, 15 e 20g de sal/L morreram após 12, duas e uma hora de exposição, respectivamente. As SL50 de 72 e 96h foram estimadas em 9,93 e 4,95g de sal/L, respectivamente. No final do teste de toxicidade, não houve diferença na sobrevivência entre as salinidades de 0, 2 e 4g de sal/L. No experimento 2, não foi observado efeito da interação entre salinidade e concentração de presas para o peso e o comprimento. Quanto maior a quantidade de presas, maior o crescimento das larvas. A sobrevivência apresentou interação entre os fatores. O aumento da salinidade proporcionou uma diminuição da sobrevivência, independentemente da concentração de presas. Dessa forma, conclui-se que a SL50 diminuiu com o aumento do tempo de exposição à água salinizada e que a larvicultura da espécie pode ser realizada em salinidades de até 2g de sal/L, com concentração de presas vivas diária inicial de 700 náuplios de Artemia/larva.(AU)

The tolerance of freshwater fish to salinity and the adequate levels of Artemia nauplii in the feeding regime during larviculture are of extreme importance to the standardization of management practices in intensive production environments. Therefore, the aim of this study was to estimate the lethal salinity (LS50) of the silver catfish Rhamdia quelen larvae and determine the effect of salinity and the concentrations of live prey in intensive larviculture of this species. In the first trial, larvae at the end of the lecithotrophic period (1.1±0.8mg) were subjected to salinities of 0, 2, 4, 6, 8, 10, 15 and 20g of salt/L for a period of 96h. In the second experiment, the catfish larvae starting the exogenous feed (1.2±0.3mg) were subjected to three salinities (freshwater 0, 2 and 4g of salt/L) and three concentrations of live prey (starting at: 300, 500, 700 Artemia nauplii/larvae/day, this amount being increased every five days). The experiment was conducted in a completely randomized design in a 3x3 factorial scheme, for a period of 15 days. In experiment 1, the catfish larvae subjected to the salinities of 10, 15 and 20g of salt/L died after 12, 2 and 1h of exposure, respectively. The LS50 at 72 and 96 h were estimated at 9.93 and 4.95g of salt/L, respectively. At the end of the toxicity test, there was no difference in the survival among the salinities of 0, 2 and 4g of salt/L. In experiment 2 no significant interaction was observed between salinity and the concentration of prey for weight and length. The increased quantity of prey increased the growth of the larvae. The rise in the salinity correlated to a decrease in survival, regardless of the prey concentration. Thus, it is concluded that the LS50 decreased with the increase in time of exposure to saltwater, and that the larviculture of this specie can be conducted in salinities of up to 2g salt/L, with a daily prey concentration starting at 700 Artemia/larvae.(AU)

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Embryological studies in fish species are useful to the understanding of their biology and systematics. The available biological data in Leiarius marmoratus are scarce and additional information about its reproductive biology is needed, mainly because this species has been commercially exploited and used in production of hybrid lineages. In order to evaluate the temporal-morphological embryonic modifications in L. marmoratus, samples of nearly 200 embryos were collected at random at different stages of development, starting from fecundation (time zero). Embryos were fixed in modified Karnovsk's solution and 2.5% glutaraldehyde, processed and analysed under optic and electron microscopy. The incubation period of L. marmoratus was equal to 14.42 h at a mean temperature of 28.3 ± 0.07°C. The following stages of embryonic development were established: zygote, cleavage, gastrula, organogenesis and hatching. These stages were divided into phases, as follows: cleavage - phases of 2, 4, 8, 16, 32 and 64 cells and morula; gastrula - phases of 25, 50, 75 and 90% of epiboly and blastopore closure; and organogenesis - neurula, segmentation and pre-larval phases. The embryogenesis of L. marmoratus was typical of neotropical teleosteans, with peculiarities in species development.

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Stages of oocyte development were described for suruvi females (Steindachneridion scriptum) kept in captivity. Oocytes of 21 mature or maturing females and ovaries of 12 immature females were fixed in Karnovsky solution for 4 and 12 hours, respectively. After, they were processed for routine histology, embedded in paraffin and stained with hematoxylin-eosin. Slides were examined under a light microscope and the oocytes were measured using the LAS EZ software, using the average between the largest and the smallest diameter of each oocyte for representation. There were six types of oocytes: Chromatin nucleolus: found in immature females, with average diameter of 9.5 ± 4.46 m; Perinucleolar: present in all developmental stages with average diameter of 67.6 ± 15.61 m; Cortical alveolar: measuring 175.6 ± 56.58 m; Vitellogenic: average diameter of 797.65 ± 136.10 m; Mature: with average diameter of 1184.98 ± 171.13 m and Atretic, which were found in mature or maturing females of suruvi.(AU)

As fases de desenvolvimento ovocitário de fêmeas de suruvi (Steindachneridion scriptum) mantidas em cativeiro foram descritas. Ovócitos de 21 fêmeas maduras ou em maturação e ovários de 12 fêmeas imaturas foram fixados em solução de Karnovsky por 4 e 12 horas, respectivamente. Em seguida, foram processados por meio das técnicas rotineiras da histologia, com inclusão em parafina e coloração em hematoxilina-eosina. As lâminas foram analisadas em microscópio de luz e os ovócitos foram medidos por meio do software LAS EZ, usando-se a média entre o maior e o menor diâmetro de cada ovócito para representá-lo. Foi possível caracterizar seis tipos de ovócitos: Cromatina-nucléolo: observado nas fêmeas imaturas, com diâmetro médio de 9,5 ±4,46 m; Perinucleolar: presente em todas as fases de desenvolvimento e com diâmetro médio de 67,6 ±15,61 m; Alvéolo-cortical: medindo 175,6 ±56,58 m; Vitelogênico: com diâmetro médio de 797,65 ±136,10 m; Maduro: com diâmetro médio de 1184,98 ±171,13 m e Atrésico, o qual foi observado em amostras obtidas de fêmeas de suruvi em maturação e maduras.(AU)

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This study describes the seminal and spermatic characteristics of fresh semen of Steindachneridion melanodermatum and investigates the effects of dilution, temperature, and storage period on its spermatic parameters. Sperm samples were collected from nine hormonally-induced males. The following parameters in fresh sperm were analyzed: seminal plasma osmolality (OSM), seminal pH, sperm motility (MOT), sperm velocity (SV) (including sperm curvilinear velocity (CVV), sperm straight-line velocity (SLV), and sperm average path velocity (APV)), total time of sperm motility (TEMP), sperm concentration (CONC), and index of sperm normality (NORM). Sperm samples from each male were diluted in a solution containing 5% fructose and 5% powdered milk, and stored at 10C and 25C. The same was carried out for sperm samples not subjected to dilution. From these samples, MOT, CVV, SLV, APV, SV, and TEMP were measured after 0 h, 5 h, 9 h, 18 h, 27 h, 36 h, 45 h, and 54 h. Males released 11.74 ± 5.38 mL of sperm, with an osmolality of 258.78 ± 29.36 mOsm.kg-1 and pH of 7.11 ± 0.31. The sperm presented a MOT of 99.86 ± 0.31% at a concentration of 1.03 × 1010 ± 3.65 × 109 spermatozoa.mL-1 with CVV of 185.58 ± 14.11 ?m.s-1, SLV of 49.15 ± 4.66 ?m.s-1, APV of 87.02 ± 4.13 ?m.s-1, SV of 106.52 ± 4.45 ?m.s-1, TEMP of 79.31 ± 5.62 s, NORM of 75.81 ± 5.71%. The resultsindicate that sperm motility, sperm velocity, and total time of sperm activation were affected by dilution,storage temperature, and storage period (p < 0.05). Procedures for semen storage should be performed with undiluted sperm cooled at 10°C, or kept undiluted at 25°C for up to 27h.(AU)

O objetivo deste estudo foi descrever os parâmetros seminais e espermáticos no sêmen fresco do Steindachneridion melanodermatum e os efeitos da diluição, da temperatura e do tempo de estocagem do sêmen sobre os parâmetros espermáticos. Foi coletado o sêmen de nove machos, induzidos hormonalmente. No sêmen fresco foram avaliados os parâmetros: osmolaridade do plasma seminal (OSM), pH seminal (pH), motilidade (MOT) e velocidades espermáticas (VCL, VLR, VMD, VE), tempo total de motilidade espermática (TEMP), concentração espermática e índice de normalidade espermática (NORM). De cada macho, amostras de sêmen que foram diluídas em solução contendo 5% de frutose e 5% de leite em pó e, armazenadas a 10 e 25ºC. O mesmo foi feito para amostras de sêmen não submetidas à diluição. Destas amostras, as MOT, VCL, VLR, VMD, VE, TEMP foram mensuradas após 0, 5, 9, 18, 27, 36, 45, 54 horas. Os machos liberaram 11,74 ± 5,38 mL de sêmen com 258,78 ± 29,36mOsm.kg-1 e pH de 7,11 ± 0,31. O sêmen apresentou 99,86 ± 0,31% de MOT, com 1,03x1010 ± 3,65x109 espermatozódes.mL-1 e, 185,58 ± 14,11?m.s-1 para VCL, 49,15 ± 4,66?m.s-1 para VLR, 87,02 ± 4,13 ?m.s-1 para VMD, 106,52 ± 4,45?m.s-1 para VE, 79,31 ± 5,62s para TEMP e 75,81 ± 5,71% de NORM. A motilidade, as velocidades e o tempo total de motilidade espermática foram influenciados (p 0,05) pela diluição, pelas temperaturas e tempos de armazenamento. A estocagem do sêmen poderá ser realizado sem diluição e resfriado a 10oC ou sem diluição, a temperatura de 25oC, pelo período deaté 27 horas.(AU)

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RESUMO

This study describes the seminal and spermatic characteristics of fresh semen of Steindachneridion melanodermatum and investigates the effects of dilution, temperature, and storage period on its spermatic parameters. Sperm samples were collected from nine hormonally-induced males. The following parameters in fresh sperm were analyzed: seminal plasma osmolality (OSM), seminal pH, sperm motility (MOT), sperm velocity (SV) (including sperm curvilinear velocity (CVV), sperm straight-line velocity (SLV), and sperm average path velocity (APV)), total time of sperm motility (TEMP), sperm concentration (CONC), and index of sperm normality (NORM). Sperm samples from each male were diluted in a solution containing 5% fructose and 5% powdered milk, and stored at 10C and 25C. The same was carried out for sperm samples not subjected to dilution. From these samples, MOT, CVV, SLV, APV, SV, and TEMP were measured after 0 h, 5 h, 9 h, 18 h, 27 h, 36 h, 45 h, and 54 h. Males released 11.74 ± 5.38 mL of sperm, with an osmolality of 258.78 ± 29.36 mOsm.kg-1 and pH of 7.11 ± 0.31. The sperm presented a MOT of 99.86 ± 0.31% at a concentration of 1.03 × 1010 ± 3.65 × 109 spermatozoa.mL-1 with CVV of 185.58 ± 14.11 ?m.s-1, SLV of 49.15 ± 4.66 ?m.s-1, APV of 87.02 ± 4.13 ?m.s-1, SV of 106.52 ± 4.45 ?m.s-1, TEMP of 79.31 ± 5.62 s, NORM of 75.81 ± 5.71%. The resultsindicate that sperm motility, sperm velocity, and total time of sperm activation were affected by dilution,storage temperature, and storage period (p < 0.05). Procedures for semen storage should be performed with undiluted sperm cooled at 10°C, or kept undiluted at 25°C for up to 27h.

O objetivo deste estudo foi descrever os parâmetros seminais e espermáticos no sêmen fresco do Steindachneridion melanodermatum e os efeitos da diluição, da temperatura e do tempo de estocagem do sêmen sobre os parâmetros espermáticos. Foi coletado o sêmen de nove machos, induzidos hormonalmente. No sêmen fresco foram avaliados os parâmetros: osmolaridade do plasma seminal (OSM), pH seminal (pH), motilidade (MOT) e velocidades espermáticas (VCL, VLR, VMD, VE), tempo total de motilidade espermática (TEMP), concentração espermática e índice de normalidade espermática (NORM). De cada macho, amostras de sêmen que foram diluídas em solução contendo 5% de frutose e 5% de leite em pó e, armazenadas a 10 e 25ºC. O mesmo foi feito para amostras de sêmen não submetidas à diluição. Destas amostras, as MOT, VCL, VLR, VMD, VE, TEMP foram mensuradas após 0, 5, 9, 18, 27, 36, 45, 54 horas. Os machos liberaram 11,74 ± 5,38 mL de sêmen com 258,78 ± 29,36mOsm.kg-1 e pH de 7,11 ± 0,31. O sêmen apresentou 99,86 ± 0,31% de MOT, com 1,03x1010 ± 3,65x109 espermatozódes.mL-1 e, 185,58 ± 14,11?m.s-1 para VCL, 49,15 ± 4,66?m.s-1 para VLR, 87,02 ± 4,13 ?m.s-1 para VMD, 106,52 ± 4,45?m.s-1 para VE, 79,31 ± 5,62s para TEMP e 75,81 ± 5,71% de NORM. A motilidade, as velocidades e o tempo total de motilidade espermática foram influenciados (p 0,05) pela diluição, pelas temperaturas e tempos de armazenamento. A estocagem do sêmen poderá ser realizado sem diluição e resfriado a 10oC ou sem diluição, a temperatura de 25oC, pelo período deaté 27 horas.

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