Effect of two diets on the fecundity of ablated and non-ablated female of Macrobrachium amazonicum

Macrobrachium amazonicum is a species of freshwater shrimp of great importance for aquaculture and to know its reproductive potential, through the study of its fertility is necessary. Therefore, this study aimed to evaluate the effect of two different diets on the reproductive performance of the species, whether or not adopting the ablation procedure. The experiment was carried out in a completely randomized design in a 2 x 2 factorial arrangement, with two types of feed (inert and fresh) and two conditions (ablated and non-ablated females), using six replicates per treatment. After 10 days of spawning, the eggs were removed and counted in their entirety. For each female, three spawns were obtained, totaling 72 samples. The fertility rate, the interval between spawning and the weight gain of the females were analyzed. There was no interaction between the studied factors, except for weight gain, in which ablated females that received fresh feed gained up to three times more weight than non-ablated females. Females that received fresh feed obtained higher fertility (1,373.9 eggs) than those that received only inert feed (1,084.1 eggs). The interval between spawns was 1.6 days shorter in ablated females.(AU)

Dynamics of fish larvae recruitment in the hydrographic basin of the Paraguay River in western Brazil

The conservation of fish assemblages depends on the longitudinal and lateral connectivity between riverine habitats, in particular during the breeding season and the initial development. This study investigated the composition and spatio-temporal structure in the ichthyoplankton of the hydrographic basin of the Paraguay River in western Brazil to identify the local spawning grounds and the importance of the longitudinal connectivity of economically valuable migratory species. Data were collected at 10 sites between two breeding seasons (2017/2018 and 2018/2019). Were collected 8,635 larvae, representing 55 taxa in 25 families, including the migratory species Brycon hilarii, Hemisorubim platyrhynchos, Piaractus mesopotamicus, Prochilodus lineatus, Pseudoplatystoma spp., Salminus brasiliensis, Sorubim lima, and Zungaro jahu, which are important fishery resources, with the highest larval densities being recorded between November and January. The Sepotuba, Paraguay, Jauru, and Cabaçal rivers were the areas of greatest connectance, and should thus be considered critical for the conservation of the longitudinal connectivity of this fluvial system, indicating that the migratory species spawn upriver. More efficient fisheries management mechanisms are needed, respecting the spawning period of migratory species, maintaining quality and longitudinal connectivity between habitats, and characteristics necessary for successful larval recruitment.(AU)

A conservação das assembleias de peixes depende da conectividade longitudinal e lateral entre habitats ribeirinhos, em especial durante o período reprodutivo e de desenvolvimento inicial. Objetivou-se avaliar a composição e a estrutura espaço-temporal do ictioplâncton da bacia hidrografia do rio Paraguai no oeste do Brasil para identificar as áreas de desova e a importância da conectividade longitudinal para a reprodução das espécies migradoras de interesse comercial. Os dados foram coletados em 10 pontos entre dois períodos reprodutivos (2017/2018 e 2018/2019). Capturaram-se 8635 larvas, pertencentes a 25 famílias e 55 táxons, incluindo espécies migradoras de interesse comercial, Brycon hilarii, Hemisorubim platyrhynchos, Piaractus mesopotamicus, Prochilodus lineatus, Pseudoplatystoma spp., Salminus brasiliensis, Sorubim lima e Zungaro jahu, que são importantes recursos pesqueiros,com maiores densidades larvais entre novembro e janeiro. Os locais com maiores interações e conectância foram os rios Sepotuba, Paraguai, Jauru e Cabaçal e, portanto, devem ser considerados áreas críticas para a conservação da conectividade longitudinal no sistema fluvial, indicando que as espécies migradoras têm desovado a montante dos locais amostrados. São necessários mecanismos de gestão pesqueira mais eficientes, respeitando o período de desova das espécies migradoras, mantendo a qualidade e conectividade longitudinal entre habitats, características necessárias ao sucesso do recrutamento larval.(AU)

Reproduction cycle of Longtail shad (Tenualosa macrura) in Bengkalis Waters, Riau, Indonesia

Tenualosa macrura is an endangered fish in Riau Province, which is classified as a protected fish. Therefore, the first step is to study the reproductive cycle, aiming o prevent these species from extinction. The observation was carried out for 13 months from January 2019 to February 2020 (except February 2019) in Indonesia's Bengkalis waters. This study's purpose was to determine the spawning season, fecundity, and behavior of this species. The results showed that the relationship between length and weight positively correlates with the length-weight of male T. macrura (R² = 0.84) and female (R² = 0.67), while the length-weight of all males and females were reported to be (R² = 0.95). Meanwhile, the relationship between fecundity and length-weight has no relationship. Furthermore, the spawning season lasted throughout the year, and it occurred at every low tide (dark moon) and high tide (full moon). Despite being discovered occasionally in a limited amount, the greatest amount of T. macrura was reported between July and September each year.(AU)

Reproduction cycle of Longtail shad (Tenualosa macrura) in Bengkalis Waters, Riau, Indonesia

Tenualosa macrura is an endangered fish in Riau Province, which is classified as a protected fish. Therefore, the first step is to study the reproductive cycle, aiming o prevent these species from extinction. The observation was carried out for 13 months from January 2019 to February 2020 (except February 2019) in Indonesia's Bengkalis waters. This study's purpose was to determine the spawning season, fecundity, and behavior of this species. The results showed that the relationship between length and weight positively correlates with the length-weight of male T. macrura (R² = 0.84) and female (R² = 0.67), while the length-weight of all males and females were reported to be (R² = 0.95). Meanwhile, the relationship between fecundity and length-weight has no relationship. Furthermore, the spawning season lasted throughout the year, and it occurred at every low tide (dark moon) and high tide (full moon). Despite being discovered occasionally in a limited amount, the greatest amount of T. macrura was reported between July and September each year.

Neonatal biometry and characterization of Amazonian Turtle nests (Podocnemis expansa)

The present study aimed to study the reproduction of the Amazon turtle (Podocnemis expansa) through the evaluation of the reproductive parameters of adult females. This study was carried out in the Crixás-Açu River, municipality of Mundo Novo, state of Goiás, Brazil. In September, the biometrics of 20 females were evaluated during the spawning period. Their nests were marked for subsequent evaluation of hatchlings, measuring the distances of each nest to the river and vegetation. The second stage consisted of the evaluation of hatchlings and characterization of nests after egg hatching. The datawere tested using the Pearson Correlation to measure the degree of linear correlation between the variables analyzed, such as the parameters of females, hatchlings, nests, and eggs. Nest depth was positively correlated with the number of eggshells found. We also found a correlation between the number of eggsshells and the distance of nests to the vegetation. Although moderate, this result indicates that as the distance to the vegetation increases, the number of eggshells found in nests decreases. The spawning site for Amazon turtle breeding is crucial to determine a higher number of eggshatching and better development of hatchlings. However, the literature is still very scarce regarding the choice of spawning grounds and the influence that vegetation may have on the development of freshwater turtle hatchlingsin Brazil.

Neonatal biometry and characterization of Amazonian Turtle nests (Podocnemis expansa)

The present study aimed to study the reproduction of the Amazon turtle (Podocnemis expansa) through the evaluation of the reproductive parameters of adult females. This study was carried out in the Crixás-Açu River, municipality of Mundo Novo, state of Goiás, Brazil. In September, the biometrics of 20 females were evaluated during the spawning period. Their nests were marked for subsequent evaluation of hatchlings, measuring the distances of each nest to the river and vegetation. The second stage consisted of the evaluation of hatchlings and characterization of nests after egg hatching. The datawere tested using the Pearson Correlation to measure the degree of linear correlation between the variables analyzed, such as the parameters of females, hatchlings, nests, and eggs. Nest depth was positively correlated with the number of eggshells found. We also found a correlation between the number of eggsshells and the distance of nests to the vegetation. Although moderate, this result indicates that as the distance to the vegetation increases, the number of eggshells found in nests decreases. The spawning site for Amazon turtle breeding is crucial to determine a higher number of eggshatching and better development of hatchlings. However, the literature is still very scarce regarding the choice of spawning grounds and the influence that vegetation may have on the development of freshwater turtle hatchlingsin Brazil.(AU)

Reproduction and fecundity of invader of internal insemination Trachelyopterus galeatus in a Neotropical floodplain

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.

Reproduction and fecundity of invader of internal insemination Trachelyopterus galeatus in a Neotropical floodplain

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)

Reproductive biology and recruitment of bluefish Pomatomus saltatrix (Perciformes: Pomatomidae) in the southwestern Atlantic

The bluefish, Pomatomus saltatrix (Linneus 1766) is captured by industrial, artisanal, and recreational fisheries throughout its distribution range. The reproductive biology of P. saltatrix in the southwestern Atlantic was studied using 1,102 specimens captured by the Brazilian commercial fleet between March 2014 and December 2015. The recruitment period was identified from records of juveniles in experimental beach seine hauls carried out on sandy beaches in the external sector of Guanabara Bay for four years (2012-2015). Based on the reproductive indices and on the macro- and microscopic analyses of the gonads, spawning peaks were identified in autumn and spring. The size at first maturity was estimated at 35.5, 38.3, and 37.4 cm for females, males, and general, respectively. Ovary analyses and measurements of the oocyte diameters indicated that bluefish are multiple spawners with asynchronous oocyte development. The batch fecundity estimate was 202,752.5 eggs and ranged from 9,800.9 to 426,787.0 eggs. The species reproduces throughout the entire study area, but it is more active in the south of Arraial do Cabo. The young-of-the-year were recorded on shallow water in all seasons, with modal peaks in the summer months. The parameters estimated in this study expand and update information on this species, providing important data for the evaluation and fisheries management of the stock of P. saltatrix in the southwestern Atlantic.

Reproductive biology and recruitment of bluefish Pomatomus saltatrix (Perciformes: Pomatomidae) in the southwestern Atlantic

ABSTRACT The bluefish, Pomatomus saltatrix (Linneus 1766) is captured by industrial, artisanal, and recreational fisheries throughout its distribution range. The reproductive biology of P. saltatrix in the southwestern Atlantic was studied using 1,102 specimens captured by the Brazilian commercial fleet between March 2014 and December 2015. The recruitment period was identified from records of juveniles in experimental beach seine hauls carried out on sandy beaches in the external sector of Guanabara Bay for four years (2012-2015). Based on the reproductive indices and on the macro- and microscopic analyses of the gonads, spawning peaks were identified in autumn and spring. The size at first maturity was estimated at 35.5, 38.3, and 37.4 cm for females, males, and general, respectively. Ovary analyses and measurements of the oocyte diameters indicated that bluefish are multiple spawners with asynchronous oocyte development. The batch fecundity estimate was 202,752.5 eggs and ranged from 9,800.9 to 426,787.0 eggs. The species reproduces throughout the entire study area, but it is more active in the south of Arraial do Cabo. The young-of-the-year were recorded on shallow water in all seasons, with modal peaks in the summer months. The parameters estimated in this study expand and update information on this species, providing important data for the evaluation and fisheries management of the stock of P. saltatrix in the southwestern Atlantic.

Reproductive biology and recruitment of bluefish Pomatomus saltatrix (Perciformes: Pomatomidae) in the southwestern Atlantic

The bluefish, Pomatomus saltatrix (Linneus 1766) is captured by industrial, artisanal, and recreational fisheries throughout its distribution range. The reproductive biology of P. saltatrix in the southwestern Atlantic was studied using 1,102 specimens captured by the Brazilian commercial fleet between March 2014 and December 2015. The recruitment period was identified from records of juveniles in experimental beach seine hauls carried out on sandy beaches in the external sector of Guanabara Bay for four years (2012-2015). Based on the reproductive indices and on the macro- and microscopic analyses of the gonads, spawning peaks were identified in autumn and spring. The size at first maturity was estimated at 35.5, 38.3, and 37.4 cm for females, males, and general, respectively. Ovary analyses and measurements of the oocyte diameters indicated that bluefish are multiple spawners with asynchronous oocyte development. The batch fecundity estimate was 202,752.5 eggs and ranged from 9,800.9 to 426,787.0 eggs. The species reproduces throughout the entire study area, but it is more active in the south of Arraial do Cabo. The young-of-the-year were recorded on shallow water in all seasons, with modal peaks in the summer months. The parameters estimated in this study expand and update information on this species, providing important data for the evaluation and fisheries management of the stock of P. saltatrix in the southwestern Atlantic.(AU)

The genital and anal papillae of Compsura heterura (Characidae: Cheirodontinae): morphological structure and possible role in insemination

The function of the genital and anal papillae for insemination in Compsura heterura is discussed based on the description of their morphologies at different stages of the life cycle and during copulation and spawning. In males and females both the genital and anal papillae are involved in copulation in C. heterura. A pre-anal organ, anterior to the anus and stretched posteriorly, is present in adult males. The openings of the urinary channel and oviduct are separate in females. During copulation, there is an approximation between the female genital and anal papillae which become temporarily juxtaposed, forming a chamber enclosing the opening of the oviduct, which may also function in sperm capture. During spawning, the lateral edges of the female genital papilla are projected anteriorly, acquiring a tubular shape for oviposition.(AU)

A função das papilas genital e anal na inseminação em Compsura heterura é discutida com base na descrição de suas morfologias em diferentes estágios do ciclo de vida e por ocasião da cópula e desova. Em machos e fêmeas, as papilas genital e anal estão envolvidas na cópula. Um órgão pré-anal, anterior ao ânus e alongado posteriormente, está presente em machos adultos. Fêmeas possuem aberturas urinária e genital separadas. Durante a cópula, ocorre uma aproximação entre as papilas genital e anal femininas, que se justapõem temporariamente, formando uma câmara fechada onde se abre o oviduto, e que serve possivelmente à captura de esperma. Durante a desova, as bordas laterais da papila genital feminina são projetadas anteriormente, adquirindo um formato tubular para ovoposição.(AU)

Efeito da sazonalidade na reprodução de peixes Characiformes em um rio Neotropical / Effect of seasonality on the reproduction of Characiformes fish in a Neotropical river

O conhecimento das táticas reprodutivas é fundamental para a compreensão das estratégias do ciclo de vida dos peixes, bem como para nortear medidas de manejo e conservação. Com isso, o presente estudo teve como objetivo verificar os aspectos relacionados à reprodução de sete espécies do rio Sorocaba, maior afluente da margem esquerda do rio Tietê e muito importante para a manutenção das espécies de peixes no trecho médio desse rio. Foram realizadas coletas mensais durante o período de setembro de 2010 a setembro de 2012 em dois pontos situados no médio e baixo Sorocaba. As espécies estudadas foram: Astyanax lacustris (Lütken, 1875), Psalidodon cf. fasciatus (Cuvier 1819), Megaleporinus obtusidens (Valenciennes 1837), Parodon nasus Kner, 1859, Prochilodus lineatus (Valenciennes, 1837), Salminus hilarii Valenciennes, 1850 e Triportheus nematurus (Kner, 1858). Foi verificada correlação significativa entre a captura das espécies e a temperatura (Spearman r = 0,79, p = 0,0001) e pluviosidade (Spearman r = 0,60, p = 0,00014). Também foi verificada correlação significativa entre os estádios em maturação e maduro, temperatura e pluviosidade, mostrando a importância desses fatores na regulação do ciclo reprodutivo das espécies nos locais estudados. Evidencia-se um padrão de sazonalidade reprodutiva, que foi confirmado pelas medianas do Índice Gonadossomático ao longo dos meses. As espécies migradoras, P. lineatus e S. hilarii, tiveram seus picos de reprodução na época de cheia do rio. Nos meses de novembro a março foi registrada a maior atividade reprodutiva, resultante da interação entre os fatores bióticos e abióticos (temperatura e nível pluviométrico), uma vez que estes atuam na maturação das gônadas.(AU)

Effect of seasonality on the reproduction of Characiformes fish in a Neotropical river. The knowledge of reproductive tactics is essential to understand the strategies of the fish life cycle, as well as to guide management and conservation measures. Thus, the present study aimed to verify the aspects related to the reproduction of seven species of the Sorocaba River, the largest tributary of the left bank of the Tietê River, and very important for the maintenance of fish species in the middle section of that river. Monthly collections were carried out from September 2010 to September 2012 at two points located in the middle and lower Sorocaba. The species studied were: Astyanax lacustris (Lütken, 1875), Psalidodon cf. fasciatus (Cuvier 1819), Megaleporinus obtusidens (Valenciennes 1837), Parodon nasus Kner, 1859, Prochilodus lineatus (Valenciennes, 1837), Salminus hilarii Valenciennes, 1850 and Triportheus nematurus (Kner, 1858). There was a significant correlation between species capture and temperature (Spearman r = 0.79, p = 0.0001) and rainfall rate (Spearman r = 0.60, p = 0.00014). There was also a significant correlation between the maturing and mature stages, temperature and rainfall rate, showing the importance of these factors in regulating the reproductive cycle of the species in the studied places. A pattern of reproductive seasonality was evidenced, which was confirmed by the medians of the Gonadosomatic Index (IGS) over the months. The migratory species P. lineatus and S. hilarii, had their peak of reproduction at the time of the riverʼs flood. In the months from November to March, the highest reproductive activity was registered, resulting from the interaction between biotic and abiotic factors (temperature and rainfall rate), since these factors act in the maturation of the gonads.(AU)

The genital and anal papillae of Compsura heterura (Characidae: Cheirodontinae): morphological structure and possible role in insemination

The function of the genital and anal papillae for insemination in Compsura heterura is discussed based on the description of their morphologies at different stages of the life cycle and during copulation and spawning. In males and females both the genital and anal papillae are involved in copulation in C. heterura. A pre-anal organ, anterior to the anus and stretched posteriorly, is present in adult males. The openings of the urinary channel and oviduct are separate in females. During copulation, there is an approximation between the female genital and anal papillae which become temporarily juxtaposed, forming a chamber enclosing the opening of the oviduct, which may also function in sperm capture. During spawning, the lateral edges of the female genital papilla are projected anteriorly, acquiring a tubular shape for oviposition.(AU)

A função das papilas genital e anal na inseminação em Compsura heterura é discutida com base na descrição de suas morfologias em diferentes estágios do ciclo de vida e por ocasião da cópula e desova. Em machos e fêmeas, as papilas genital e anal estão envolvidas na cópula. Um órgão pré-anal, anterior ao ânus e alongado posteriormente, está presente em machos adultos. Fêmeas possuem aberturas urinária e genital separadas. Durante a cópula, ocorre uma aproximação entre as papilas genital e anal femininas, que se justapõem temporariamente, formando uma câmara fechada onde se abre o oviduto, e que serve possivelmente à captura de esperma. Durante a desova, as bordas laterais da papila genital feminina são projetadas anteriormente, adquirindo um formato tubular para ovoposição.(AU)

Reproductive cycle of the mangrove oyster, Crassostrea rhizophorae (Bivalvia: Ostreidae) cultured in a macrotidal high-salinity zone on the Amazon mangrove coast of Brazil / Ciclo reprodutivo da ostra do mangue, Crassostrea rhizophorae (Bivalvia: Ostreidae) cultivada em uma zona de macromarés de alta salinidade na costa de manguezais da Amazônia do Brasil

This study aimed to establish the reproductive cycle of the mangrove oyster, Crassostrea rhizophorae cultured in the macrotidal estuary of the Paciência River, Maranhão state, on the northeastern coast of Brazil, and its relationship with environmental factors. Oysters were collected monthly throughout 2013 for histological analysis of sex ratio, gonadal development and condition index. The sex ratio was 1:1.39 (M:F) and only 5 specimens presented hermaphroditism. The breeding process was continuous throughout the year and mature (IIIA stage) and spawning oysters (IIIB stage) were present in practically all months. Low variation in temperature seemed to be the main factor for the continuity of the reproductive cycle. Besides temperature, the relationship between rainfall, salinity and primary productivity affected the stimulus and timing of reproductive events. The rainy season, with low values of salinity and high values of chlorophyll a and particulate organic matter, appeared to be the main reproductive period, with release of gametes and production and maturation of new gamete cohorts in the short term. In the tropics, where gamete maturation and release seem to be continuous and concomitant, the condition index does not appear to be the best method to assess reserve accumulation peaks and gonadal repletion.(AU)

Este estudo teve como objetivo estabelecer o ciclo reprodutivo da ostra do mangue, Crassostrea rhizophorae cultivada no estuário de macromarés do Rio Paciência, Maranhão, na costa nordeste do Brasil, e suas relações com fatores ambientais. As ostras foram coletadas mensalmente ao longo de 2013 para análise histológica da proporção sexual, desenvolvimento gonadal e índice de condição. A proporção sexual foi de 1:1,39 (M:F) e apenas 5 espécimes apresentaram hermafroditismo. A maturação foi contínua ao longo do ano e ostras maduras (estágio IIIA) e em desova (estágio IIIB) estiveram presentes em praticamente todos os meses. A baixa variação de temperatura parece ser o principal fator para a continuidade da gametogênese. Entretanto, além da temperatura, a relação entre precipitação, salinidade e produtividade primária afetou o estímulo e o tempo dos eventos reprodutivos. A estação chuvosa, com baixos valores de salinidade e altos valores de clorofila a e matéria orgânica particulada, pareceu ser o principal período reprodutivo, com liberação de gametas e produção e maturação de novas coortes de gametas em curto prazo. Nos trópicos, onde a maturação e liberação de gametas parecem ser contínuas e concomitantes, o índice de condição não se apresenta como o melhor método para avaliar os picos de acúmulo de reserva e desenvolvimento gonadal.(AU)

Efeito da sazonalidade na reprodução de peixes Characiformes em um rio Neotropical / Effect of seasonality on the reproduction of Characiformes fish in a Neotropical river

O conhecimento das táticas reprodutivas é fundamental para a compreensão das estratégias do ciclo de vida dos peixes, bem como para nortear medidas de manejo e conservação. Com isso, o presente estudo teve como objetivo verificar os aspectos relacionados à reprodução de sete espécies do rio Sorocaba, maior afluente da margem esquerda do rio Tietê e muito importante para a manutenção das espécies de peixes no trecho médio desse rio. Foram realizadas coletas mensais durante o período de setembro de 2010 a setembro de 2012 em dois pontos situados no médio e baixo Sorocaba. As espécies estudadas foram: Astyanax lacustris (Lütken, 1875), Psalidodon cf. fasciatus (Cuvier 1819), Megaleporinus obtusidens (Valenciennes 1837), Parodon nasus Kner, 1859, Prochilodus lineatus (Valenciennes, 1837), Salminus hilarii Valenciennes, 1850 e Triportheus nematurus (Kner, 1858). Foi verificada correlação significativa entre a captura das espécies e a temperatura (Spearman r = 0,79, p = 0,0001) e pluviosidade (Spearman r = 0,60, p = 0,00014). Também foi verificada correlação significativa entre os estádios em maturação e maduro, temperatura e pluviosidade, mostrando a importância desses fatores na regulação do ciclo reprodutivo das espécies nos locais estudados. Evidencia-se um padrão de sazonalidade reprodutiva, que foi confirmado pelas medianas do Índice Gonadossomático ao longo dos meses. As espécies migradoras, P. lineatus e S. hilarii, tiveram seus picos de reprodução na época de cheia do rio. Nos meses de novembro a março foi registrada a maior atividade reprodutiva, resultante da interação entre os fatores bióticos e abióticos (temperatura e nível pluviométrico), uma vez que estes atuam na maturação das gônadas.

Effect of seasonality on the reproduction of Characiformes fish in a Neotropical river. The knowledge of reproductive tactics is essential to understand the strategies of the fish life cycle, as well as to guide management and conservation measures. Thus, the present study aimed to verify the aspects related to the reproduction of seven species of the Sorocaba River, the largest tributary of the left bank of the Tietê River, and very important for the maintenance of fish species in the middle section of that river. Monthly collections were carried out from September 2010 to September 2012 at two points located in the middle and lower Sorocaba. The species studied were: Astyanax lacustris (Lütken, 1875), Psalidodon cf. fasciatus (Cuvier 1819), Megaleporinus obtusidens (Valenciennes 1837), Parodon nasus Kner, 1859, Prochilodus lineatus (Valenciennes, 1837), Salminus hilarii Valenciennes, 1850 and Triportheus nematurus (Kner, 1858). There was a significant correlation between species capture and temperature (Spearman r = 0.79, p = 0.0001) and rainfall rate (Spearman r = 0.60, p = 0.00014). There was also a significant correlation between the maturing and mature stages, temperature and rainfall rate, showing the importance of these factors in regulating the reproductive cycle of the species in the studied places. A pattern of reproductive seasonality was evidenced, which was confirmed by the medians of the Gonadosomatic Index (IGS) over the months. The migratory species P. lineatus and S. hilarii, had their peak of reproduction at the time of the riverʼs flood. In the months from November to March, the highest reproductive activity was registered, resulting from the interaction between biotic and abiotic factors (temperature and rainfall rate), since these factors act in the maturation of the gonads.

Efeito da sazonalidade na reprodução de peixes Characiformes em um rio Neotropical

ABSTRACT Effect of seasonality on the reproduction of Characiformes fish in a Neotropical river. The knowledge of reproductive tactics is essential to understand the strategies of the fish life cycle, as well as to guide management and conservation measures. Thus, the present study aimed to verify the aspects related to the reproduction of seven species of the Sorocaba River, the largest tributary of the left bank of the Tietê River, and very important for the maintenance of fish species in the middle section of that river. Monthly collections were carried out from September 2010 to September 2012 at two points located in the middle and lower Sorocaba. The species studied were: Astyanax lacustris (Lütken, 1875), Psalidodon cf. fasciatus (Cuvier 1819), Megaleporinus obtusidens (Valenciennes 1837), Parodon nasus Kner, 1859, Prochilodus lineatus (Valenciennes, 1837), Salminus hilarii Valenciennes, 1850 and Triportheus nematurus (Kner, 1858). There was a significant correlation between species capture and temperature (Spearman r = 0.79, p = 0.0001) and rainfall rate (Spearman r = 0.60, p = 0.00014). There was also a significant correlation between the maturing and mature stages, temperature and rainfall rate, showing the importance of these factors in regulating the reproductive cycle of the species in the studied places. A pattern of reproductive seasonality was evidenced, which was confirmed by the medians of the Gonadosomatic Index (IGS) over the months. The migratory species P. lineatus and S. hilarii, had their peak of reproduction at the time of the rivers flood. In the months from November to March, the highest reproductive activity was registered, resulting from the interaction between biotic and abiotic factors (temperature and rainfall rate), since these factors act in the maturation of the gonads.

RESUMO O conhecimento das táticas reprodutivas é fundamental para a compreensão das estratégias do ciclo de vida dos peixes, bem como para nortear medidas de manejo e conservação. Com isso, o presente estudo teve como objetivo verificar os aspectos relacionados à reprodução de sete espécies do rio Sorocaba, maior afluente da margem esquerda do rio Tietê e muito importante para a manutenção das espécies de peixes no trecho médio desse rio. Foram realizadas coletas mensais durante o período de setembro de 2010 a setembro de 2012 em dois pontos situados no médio e baixo Sorocaba. As espécies estudadas foram: Astyanax lacustris (Lütken, 1875), Psalidodon cf. fasciatus (Cuvier 1819), Megaleporinus obtusidens (Valenciennes 1837), Parodon nasus Kner, 1859, Prochilodus lineatus (Valenciennes, 1837), Salminus hilarii Valenciennes, 1850 e Triportheus nematurus (Kner, 1858). Foi verificada correlação significativa entre a captura das espécies e a temperatura (Spearman r = 0,79, p = 0,0001) e pluviosidade (Spearman r = 0,60, p = 0,00014). Também foi verificada correlação significativa entre os estádios em maturação e maduro, temperatura e pluviosidade, mostrando a importância desses fatores na regulação do ciclo reprodutivo das espécies nos locais estudados. Evidencia-se um padrão de sazonalidade reprodutiva, que foi confirmado pelas medianas do Índice Gonadossomático ao longo dos meses. As espécies migradoras, P. lineatus e S. hilarii, tiveram seus picos de reprodução na época de cheia do rio. Nos meses de novembro a março foi registrada a maior atividade reprodutiva, resultante da interação entre os fatores bióticos e abióticos (temperatura e nível pluviométrico), uma vez que estes atuam na maturação das gônadas.

Reproduction aspects of cobia caught in Pernambuco Coast, northeastern Brazil / Aspectos da reprodução do beijupirá capturado na costa de Pernambuco, nordeste do Brasil

Aspects of the reproduction of cobia (Rachycentron canadum) population from the coast of Pernambuco State, Northeastern Brazil, were studied from February 2004 to August 2006. One hundred eleven individuals were analyzed: 54 females with fork length (FL) ranging from 40 to 137 cm (mean ± standard deviation: 90.7 ± 18.1 cm) and 57 males with FL from 43 to 114.5 cm (82.4 ± 17.0 cm). Histological analysis was used to identify maturational phases. Spawning capable females were found from August to May, except in December, while mature males were present throughout the year, except in July. Size at first maturity (L50) obtained by Bayesian analysis was 72.51 cm FL for females and 60.69 cm FL for males. Overall batch fecundity ranged from 192,063 to 1,600,513 oocytes (722,398 ± 430,911) and mean relative batch fecundity ranged from 32.9 to 104.8 (71.1 ± 29.8) oocytes per gram of female body weight. The data indicate that the reproduction of cobia off the coast of Pernambuco occurs throughout the year, but with peaks between February and April, period in which gonadosomatic indices reach the maximum values and then decrease until May for females and males.

Aspectos da reprodução do beijupirá (Rachycentron canadum) na população da costa do Estado de Pernambuco, Nordeste do Brasil, foram estudados de fevereiro de 2004 a agosto de 2006. Cento e onze indivíduos foram analisados, 54 fêmeas com comprimento zoológico (CZ) variando de 40 a 137 cm (média ± DP: 90,7 ± 18,1 cm), e 57 machos com CZ de 43 a 114,5 cm (82,4 ± 17,0 cm). Foi utilizada a análise histológica para identificar as fases de maturação. Foram encontradas fêmeas maduras de agosto a maio, exceto em dezembro, enquanto machos maduros foram presentes ao longo de todo o ano, exceto em julho. O tamanho de primeira maturação (L50), obtido por análise Bayesiana, foi de 72,51 cm CZ para fêmeas e 60,69 cm CZ para machos. A fecundidade total do lote variou de 192.063 a 1.600.513 oócitos (722.398 ± 430.911) e a fecundidade média relativa do lote variou de 32,9 a 104,8 (71,1 ± 29,8) oócitos por grama de peso corporal de fêmeas. Os dados indicam que a reprodução do beijupirá na costa de Pernambuco ocorre ao longo do ano, com picos entre fevereiro e abril, período em que os índices gonadossomáticos alcançam os valores máximos e depois decrescem até maio para fêmeas e machos.

Reproduction aspects of cobia caught in Pernambuco Coast, northeastern Brazil / Aspectos da reprodução do beijupirá capturado na costa de Pernambuco, nordeste do Brasil

Aspects of the reproduction of cobia (Rachycentron canadum) population from the coast of Pernambuco State, Northeastern Brazil, were studied from February 2004 to August 2006. One hundred eleven individuals were analyzed: 54 females with fork length (FL) ranging from 40 to 137 cm (mean ± standard deviation: 90.7 ± 18.1 cm) and 57 males with FL from 43 to 114.5 cm (82.4 ± 17.0 cm). Histological analysis was used to identify maturational phases. Spawning capable females were found from August to May, except in December, while mature males were present throughout the year, except in July. Size at first maturity (L50) obtained by Bayesian analysis was 72.51 cm FL for females and 60.69 cm FL for males. Overall batch fecundity ranged from 192,063 to 1,600,513 oocytes (722,398 ± 430,911) and mean relative batch fecundity ranged from 32.9 to 104.8 (71.1 ± 29.8) oocytes per gram of female body weight. The data indicate that the reproduction of cobia off the coast of Pernambuco occurs throughout the year, but with peaks between February and April, period in which gonadosomatic indices reach the maximum values and then decrease until May for females and males.(AU)

Aspectos da reprodução do beijupirá (Rachycentron canadum) na população da costa do Estado de Pernambuco, Nordeste do Brasil, foram estudados de fevereiro de 2004 a agosto de 2006. Cento e onze indivíduos foram analisados, 54 fêmeas com comprimento zoológico (CZ) variando de 40 a 137 cm (média ± DP: 90,7 ± 18,1 cm), e 57 machos com CZ de 43 a 114,5 cm (82,4 ± 17,0 cm). Foi utilizada a análise histológica para identificar as fases de maturação. Foram encontradas fêmeas maduras de agosto a maio, exceto em dezembro, enquanto machos maduros foram presentes ao longo de todo o ano, exceto em julho. O tamanho de primeira maturação (L50), obtido por análise Bayesiana, foi de 72,51 cm CZ para fêmeas e 60,69 cm CZ para machos. A fecundidade total do lote variou de 192.063 a 1.600.513 oócitos (722.398 ± 430.911) e a fecundidade média relativa do lote variou de 32,9 a 104,8 (71,1 ± 29,8) oócitos por grama de peso corporal de fêmeas. Os dados indicam que a reprodução do beijupirá na costa de Pernambuco ocorre ao longo do ano, com picos entre fevereiro e abril, período em que os índices gonadossomáticos alcançam os valores máximos e depois decrescem até maio para fêmeas e machos.(AU)

Analysis of reproductive biology and spawning season of the pink ear emperor Lethrinus lentjan, from marine ecosystem

A total of 593 samples of Lethrinus lentjan (Lacepede, 1802) were collected from the Red Sea, Jeddah, Saudi Arabia, to study their productive biology and spawning season of the local population. Sampling was carried out on a monthly basis for a period of one year. The monthly sex ratios indicated that females were dominant throughout the study period, with an overall male:female sex ratio of 1:7.98, although males were larger than females. The highest monthly performance maturation index (PMI), as well as the male and female gonadosomatic index (GSI) and ovarian maturation rate (OMR) were observed in February and March. Histological examination of the gonads confirmed the process of sexual transformation in this fish species, wherein individuals mature first as female, and then change sex to male (protogynous hermaphroditism). Histological sections also showed that the sexual maturation of males of L. lenjtan comprised three main stages, while the sexual development of females could be classified into four main stages. Extended spawning in the form of batches released during different months throughout the year were recorded for this fish species, with the main spawning season in February and March, and an additional, shorter spawning season in September.