Co-feeding period on the survival and growth of larvae (Botia lohachata) during the feeding transition / Co-feeding na sobrevivência e crescimento de larvas de botia yoyo Botia lohachata durante a transição alimentar

ABSTRACT: This study evaluated the effect of the co-feeding (C) period on the growth and survival of larvae of the yo-yo loach Botia lohachata ornamental species during the weaning period from live food (LF) to inert food (IF). The breeders were subjected to induced spawning using crude pituitary homogenate. A total of 2,400 larvae were used with an average initial weight of 0.39 ± 0.09 mg and an average total length of 4.08 ± 0.21 mm, from a single breeding pair. The live food was newly hatched nauplii of Artemia franciscana, and the inert diet was a commercial ration with 55% crude protein and two particle sizes (142-350 µm and 350-500 µm). As the first food, all larvae received A. franciscana during the first six days, except for the fasting (NC) and inert food (IF) groups. The following co-feeding strategies were employed: C4 = 4 days of co-feeding, C8 = 8 days of co-feeding, C12 = 12 days of co-feeding, and LF = Artemia during the entire experimental period. The longest period with live food promoted better larval growth rates. The specific growth rate of larvae fed live food during the entire period (LF) was higher than that of the other groups, followed by the co-feeding strategies. There was no effect (P > 0.01) on larval survival in the LF, C12, C8, and C4 groups, which ranged from 41% to 53% after 30 days. Treatment R resulted in high mortality and low growth, suggesting that live food should be the first food source for B. lohachata larvae.

RESUMO: Este estudo teve como objetivo avaliar o efeito do período de co-alimentação (C) no crescimento e sobrevivência de larvas da espécie ornamental Botia lohachata durante o período de desmame de alimento vivo (LF) para alimento inerte (IF). Os reprodutores foram submetidos à desova induzida com homogeneizado de hipófise. Foram utilizadas 2.400 larvas com peso inicial médio de 0,39 ± 0,09 mg e comprimento total médio de 4,08 ± 0,21 mm, de um único casal reprodutor. O alimento vivo foi náuplios recém-eclodidos de Artemia franciscana, e a dieta inerte foi uma ração comercial com 55% de proteína bruta e dois tamanhos de partículas (142-350 µm e 350-500 µm). Como primeiro alimento, todas as larvas receberam A. franciscana durante os primeiros seis dias, exceto os grupos jejum (NC) e alimento inerte (IF). As seguintes estratégias de co-alimentação foram empregadas: C4 = 4 dias de co-alimentação, C8 = 8 dias de co-alimentação, C12 = 12 dias de co-alimentação e LF = Artemia durante todo o período experimental. O maior período com alimento vivo promoveu melhores taxas de crescimento larval. A taxa de crescimento específico das larvas alimentadas com ração viva durante todo o período (LF) foi maior que a dos demais grupos, seguida das estratégias de co-alimentação. Não houve efeito (P > 0,01) na sobrevivência larval nos grupos LF, C12, C8 e C4, que variou de 41% a 53% após 30 dias. O tratamento IN resultou em alta mortalidade e baixo crescimento, sugerindo que o alimento vivo deve ser a primeira fonte de alimento para as larvas de B. lohachata.

Duration of co-feeding on the Nishikigoi Cyprinus carpio larvae during weaning from live to inert food in an indoor system / Período de co-alimentação na transição alimentar de larvas de Nishikigoi Cyprinus carpio em sistema “in door”

This study aimed to evaluate the effects of the co-feeding period (C) on the survival and growth of larvae of nishikigoi Cyprinus carpio, during the weaning period from live to inert food. A total of 1680 larvae with initial weight of 1.33 ± 0.12mg and initial length of 6.0 ± 0.33mm were used. The inert diet used was a commercial ration with 55% crude protein and the live food was the newly hatched nauplii of Artemia franciscana. The experiment was conducted following a completely randomized design with six treatments and four replications. Treatments constituted of: a) LF = supply of live food throughout the experimental period; b) C4 = 6 days of live food + 4 days of co-feeding (inert diet and live food) + 16 days of inert diet; c) C8 = 6 days of live food + 8 days of co-feeding + 12 days of inert diet; d) C12 = 6 days of live food + 12 days of co-feeding + 8 days of inert diet; e) IF = supply with inert diet throughout the experimental period; and f) F = fasting. Our results showed that the co-feeding period influences the survival and growth of the larvae. Survival in the treatment with the longest co-feeding period showed an improvement of over 70% when compared to the shortest period. Further, we noted a doubling of the juvenile weight after 26 days of age. There was a quadratic effect for all parameters, with maximum points ranging between 19.4 and 22.6 days of supply of live food. We concluded that the supply of commercial feed as exclusive food is unworkable in nishikigoi larviculture.(AU)

Com o objetivo de avaliar os efeitos do período de co-alimentação (C) na sobrevivência e crescimento de larvas de nishikigoi Cyprinus carpio, durante o período de transição de alimentos vivos (AV) para dieta inerte (DI), foram utilizados um total de 1680 larvas com peso inicial de 1,33 ± 0,12mg e comprimento inicial de 6,0 ± 0,33mm. Para a dieta inerte foi utilizada uma ração comercial com 55% de proteína bruta e como alimento vivo, nauplios recém eclodidos de Artemia franciscana. O experimento foi conduzido em delineamento inteiramente casualizado com seis tratamentos e quatro repetições. Os tratamentos foram constituídos por: LF = suprimento de alimento vivo ao longo de todo período experimental; C4 = 6 dias de alimento vivo + 4 dias de co-alimentação (dieta inerte e alimento vivo) + 16 dias de dieta inerte; C8 = 6 dias de alimento vivo + 8 dias de co-alimentação + 12 dias de dieta inerte; C12 = 6 dias de alimento vivo + 12 dias de co-alimentação + 8 dias de dieta inerte; ID = dieta inerte durante todo o período experimental, J = jejum. O período de co-alimentação influencia a sobrevivência e o crescimento das larvas melhorando mais de 70% a sobrevida entre os períodos de co-alimentação mais longos e curtos testados. Além disso, foi verificado um aumento de duas vezes o peso juvenil após 26 dias de idade. Houve um efeito quadrático para todos os parâmetros, com pontos máximos variando entre 19,4 e 22,6 dias de suprimento de alimentos vivos. Também é possível concluir que o fornecimento de alimentação comercial, como alimento exclusivo, é inviável na larvicultura de nishikigoi.(AU)

Duration of co-feeding on the Nishikigoi Cyprinus carpio larvae during weaning from live to inert food in an indoor system / Período de co-alimentação na transição alimentar de larvas de Nishikigoi Cyprinus carpio em sistema "in door"

ABSTRACT: This study aimed to evaluate the effects of the co-feeding period (C) on the survival and growth of larvae of nishikigoi Cyprinus carpio, during the weaning period from live to inert food. A total of 1680 larvae with initial weight of 1.33 ± 0.12mg and initial length of 6.0 ± 0.33mm were used. The inert diet used was a commercial ration with 55% crude protein and the live food was the newly hatched nauplii of Artemia franciscana. The experiment was conducted following a completely randomized design with six treatments and four replications. Treatments constituted of: a) LF = supply of live food throughout the experimental period; b) C4 = 6 days of live food + 4 days of co-feeding (inert diet and live food) + 16 days of inert diet; c) C8 = 6 days of live food + 8 days of co-feeding + 12 days of inert diet; d) C12 = 6 days of live food + 12 days of co-feeding + 8 days of inert diet; e) IF = supply with inert diet throughout the experimental period; and f) F = fasting. Our results showed that the co-feeding period influences the survival and growth of the larvae. Survival in the treatment with the longest co-feeding period showed an improvement of over 70% when compared to the shortest period. Further, we noted a doubling of the juvenile weight after 26 days of age. There was a quadratic effect for all parameters, with maximum points ranging between 19.4 and 22.6 days of supply of live food. We concluded that the supply of commercial feed as exclusive food is unworkable in nishikigoi larviculture.

RESUMO: Com o objetivo de avaliar os efeitos do período de co-alimentação (C) na sobrevivência e crescimento de larvas de nishikigoi Cyprinus carpio, durante o período de transição de alimentos vivos (AV) para dieta inerte (DI), foram utilizados um total de 1680 larvas com peso inicial de 1,33 ± 0,12mg e comprimento inicial de 6,0 ± 0,33mm. Para a dieta inerte foi utilizada uma ração comercial com 55% de proteína bruta e como alimento vivo, nauplios recém eclodidos de Artemia franciscana. O experimento foi conduzido em delineamento inteiramente casualizado com seis tratamentos e quatro repetições. Os tratamentos foram constituídos por: LF = suprimento de alimento vivo ao longo de todo período experimental; C4 = 6 dias de alimento vivo + 4 dias de co-alimentação (dieta inerte e alimento vivo) + 16 dias de dieta inerte; C8 = 6 dias de alimento vivo + 8 dias de co-alimentação + 12 dias de dieta inerte; C12 = 6 dias de alimento vivo + 12 dias de co-alimentação + 8 dias de dieta inerte; ID = dieta inerte durante todo o período experimental, J = jejum. O período de co-alimentação influencia a sobrevivência e o crescimento das larvas melhorando mais de 70% a sobrevida entre os períodos de co-alimentação mais longos e curtos testados. Além disso, foi verificado um aumento de duas vezes o peso juvenil após 26 dias de idade. Houve um efeito quadrático para todos os parâmetros, com pontos máximos variando entre 19,4 e 22,6 dias de suprimento de alimentos vivos. Também é possível concluir que o fornecimento de alimentação comercial, como alimento exclusivo, é inviável na larvicultura de nishikigoi.

Duration of co-feeding on the Nishikigoi Cyprinus carpio larvae during weaning from live to inert food in an indoor system / Período de co-alimentação na transição alimentar de larvas de Nishikigoi Cyprinus carpio em sistema “in door”

This study aimed to evaluate the effects of the co-feeding period (C) on the survival and growth of larvae of nishikigoi Cyprinus carpio, during the weaning period from live to inert food. A total of 1680 larvae with initial weight of 1.33 ± 0.12mg and initial length of 6.0 ± 0.33mm were used. The inert diet used was a commercial ration with 55% crude protein and the live food was the newly hatched nauplii of Artemia franciscana. The experiment was conducted following a completely randomized design with six treatments and four replications. Treatments constituted of: a) LF = supply of live food throughout the experimental period; b) C4 = 6 days of live food + 4 days of co-feeding (inert diet and live food) + 16 days of inert diet; c) C8 = 6 days of live food + 8 days of co-feeding + 12 days of inert diet; d) C12 = 6 days of live food + 12 days of co-feeding + 8 days of inert diet; e) IF = supply with inert diet throughout the experimental period; and f) F = fasting. Our results showed that the co-feeding period influences the survival and growth of the larvae. Survival in the treatment with the longest co-feeding period showed an improvement of over 70% when compared to the shortest period. Further, we noted a doubling of the juvenile weight after 26 days of age. There was a quadratic effect for all parameters, with maximum points ranging between 19.4 and 22.6 days of supply of live food. We concluded that the supply of commercial feed as exclusive food is unworkable in nishikigoi larviculture.

Com o objetivo de avaliar os efeitos do período de co-alimentação (C) na sobrevivência e crescimento de larvas de nishikigoi Cyprinus carpio, durante o período de transição de alimentos vivos (AV) para dieta inerte (DI), foram utilizados um total de 1680 larvas com peso inicial de 1,33 ± 0,12mg e comprimento inicial de 6,0 ± 0,33mm. Para a dieta inerte foi utilizada uma ração comercial com 55% de proteína bruta e como alimento vivo, nauplios recém eclodidos de Artemia franciscana. O experimento foi conduzido em delineamento inteiramente casualizado com seis tratamentos e quatro repetições. Os tratamentos foram constituídos por: LF = suprimento de alimento vivo ao longo de todo período experimental; C4 = 6 dias de alimento vivo + 4 dias de co-alimentação (dieta inerte e alimento vivo) + 16 dias de dieta inerte; C8 = 6 dias de alimento vivo + 8 dias de co-alimentação + 12 dias de dieta inerte; C12 = 6 dias de alimento vivo + 12 dias de co-alimentação + 8 dias de dieta inerte; ID = dieta inerte durante todo o período experimental, J = jejum. O período de co-alimentação influencia a sobrevivência e o crescimento das larvas melhorando mais de 70% a sobrevida entre os períodos de co-alimentação mais longos e curtos testados. Além disso, foi verificado um aumento de duas vezes o peso juvenil após 26 dias de idade. Houve um efeito quadrático para todos os parâmetros, com pontos máximos variando entre 19,4 e 22,6 dias de suprimento de alimentos vivos. Também é possível concluir que o fornecimento de alimentação comercial, como alimento exclusivo, é inviável na larvicultura de nishikigoi.

Effect of propolis extract on angelfish larval performance and transport / Efeito do extrato de própolis no desempenho de larvas e transporte de acará bandeira

This study aimed to evaluate the influence propolis extract inclusion to the feed mixture for juvenile angelfish (Pterophyllum scalare) on larval performance and transport. Levels of propolis extract inclusion consisted of 0, 300, 600, 900, and 1200 mg.kg-1 of feed. After 14 days of hatching, unmetamorphosed larvae with a total length of 18.4 mm and 0.11 g initial weight were used. Six-hundred larvae were divided into 20 experimental units, totalizing 30 larvae each. Experimental units consisted of polythene containers with independent water input and output and a level controller. Each unit was controlled for maintenance of 40 L water within a recirculation system. After offering feed containing propolis extract, five fish from each experimental unit were packed in bags for transportation only with atmospheric air, without pure oxygen addition. The bags were filled with 300 mL water on a 2:1 basis of air and water respectively. The total transport time was considered until the death of the third fish in package. At the end of the experiment, data underwent statistical analysis through Statistical Analysis System (SAS, 2001). Results showed there was no significant difference (P<0.05) neither for any of the studied zootechnical variables (standard length, total length, height, and weight) nor for the transport of juveniles. In conclusion, propolis extract addition to angelfish feed was ineffective for larval performance and for transportation of juveniles, at the levels tested here.(AU)

Este estudo teve como objetivo avaliar a influência da inclusão de extrato de própolis na mistura de ração para juvenis de acará bandeira (Pterophyllum scalare) no desempenho larval e transporte. Os níveis de inclusão de extrato de própolis consistiam em 0, 300, 600, 900 e 1200 mg.kg-1 de alimento. Após 14 dias de incubação, utilizaram-se larvas não metamorfoseadas com um comprimento total de 18,4 mm e 0,11 g de peso inicial. Seiscentas larvas foram divididas em 20 unidades experimentais, totalizando 30 larvas cada. As unidades experimentais consistiram em recipientes de polietileno com entrada e saída independentes de água e um controlador de nível. Cada unidade foi controlada mantendo-se o volume de 40 L de água, compondo um sistema de recirculação. Após a oferta de alimento contendo extrato de própolis, cinco peixes de cada unidade experimental foram acondicionados em sacos para transporte somente com ar atmosférico, sem adição de oxigênio puro. Os sacos foram cheios com 300 ml de água na proporção 2:1 de ar e água, respectivamente. O tempo total de transporte foi considerado até a morte do terceiro peixe na embalagem. No final do experimento, os dados foram submetidos à análise estatística através do Statistical Analysis System (SAS, 2001). Os resultados mostraram que não houve diferença significativa (P<0.05) nem para nenhuma das variáveis zootécnicas estudadas (comprimento padrão, comprimento total, altura e peso) nem para o transporte de juvenis. Em conclusão, a adição de extrato de própolis para a alimentação de acará bandeira foi ineficaz para o desempenho larval e para o transporte de juvenis, nos níveis aqui testados.(AU)

Effect of propolis extract on angelfish larval performance and transport / Efeito do extrato de própolis no desempenho de larvas e transporte de acará bandeira

This study aimed to evaluate the influence propolis extract inclusion to the feed mixture for juvenile angelfish (Pterophyllum scalare) on larval performance and transport. Levels of propolis extract inclusion consisted of 0, 300, 600, 900, and 1200 mg.kg-1 of feed. After 14 days of hatching, unmetamorphosed larvae with a total length of 18.4 mm and 0.11 g initial weight were used. Six-hundred larvae were divided into 20 experimental units, totalizing 30 larvae each. Experimental units consisted of polythene containers with independent water input and output and a level controller. Each unit was controlled for maintenance of 40 L water within a recirculation system. After offering feed containing propolis extract, five fish from each experimental unit were packed in bags for transportation only with atmospheric air, without pure oxygen addition. The bags were filled with 300 mL water on a 2:1 basis of air and water respectively. The total transport time was considered until the death of the third fish in package. At the end of the experiment, data underwent statistical analysis through Statistical Analysis System (SAS, 2001). Results showed there was no significant difference (P<0.05) neither for any of the studied zootechnical variables (standard length, total length, height, and weight) nor for the transport of juveniles. In conclusion, propolis extract addition to angelfish feed was ineffective for larval performance and for transportation of juveniles, at the levels tested here.

Este estudo teve como objetivo avaliar a influência da inclusão de extrato de própolis na mistura de ração para juvenis de acará bandeira (Pterophyllum scalare) no desempenho larval e transporte. Os níveis de inclusão de extrato de própolis consistiam em 0, 300, 600, 900 e 1200 mg.kg-1 de alimento. Após 14 dias de incubação, utilizaram-se larvas não metamorfoseadas com um comprimento total de 18,4 mm e 0,11 g de peso inicial. Seiscentas larvas foram divididas em 20 unidades experimentais, totalizando 30 larvas cada. As unidades experimentais consistiram em recipientes de polietileno com entrada e saída independentes de água e um controlador de nível. Cada unidade foi controlada mantendo-se o volume de 40 L de água, compondo um sistema de recirculação. Após a oferta de alimento contendo extrato de própolis, cinco peixes de cada unidade experimental foram acondicionados em sacos para transporte somente com ar atmosférico, sem adição de oxigênio puro. Os sacos foram cheios com 300 ml de água na proporção 2:1 de ar e água, respectivamente. O tempo total de transporte foi considerado até a morte do terceiro peixe na embalagem. No final do experimento, os dados foram submetidos à análise estatística através do Statistical Analysis System (SAS, 2001). Os resultados mostraram que não houve diferença significativa (P<0.05) nem para nenhuma das variáveis zootécnicas estudadas (comprimento padrão, comprimento total, altura e peso) nem para o transporte de juvenis. Em conclusão, a adição de extrato de própolis para a alimentação de acará bandeira foi ineficaz para o desempenho larval e para o transporte de juvenis, nos níveis aqui testados.

Effect of temperature during embryonic development and first feeding of Trichogaster leeri larvae.

Temperature is an environmental factor that influences the development of fish, and when changed abruptly can lead to high mortality. Some species of fish are influenced by this factor, exhibiting a longer time for embryonic development and time to first feeding. This study aims to evaluate the effect of water temperature on embryonic and larval development up to first feeding, to describe the time in hours post fertilization (hpf) of the emergence of different structures and to determine the best hatching rate and survival of animals under different treatments. Five different egg incubation temperatures were used (24, 26, 28, 30 or 32°C, respectively). The eggs were observed at regular intervals of 30 min up to 24 h, every 2 h until 48 h and every 4 h until the display of first feeding in all treatments. Embryonic development was longer for eggs incubated at 24°C and the best results for hatching rate and survival of spawning efficiency were at 28°C. We recommend that incubation of Trichogaster leeri eggs is carried out at 28°C up to the first feeding of larvae.

Effect of temperature on embryonic development of Melanotaenia boesemani (Allen and Cross, 1982).

The present study aimed to provide data on the time required for Melanotaenia boesemani to complete embryonic development, and to investigate the influence that incubation at different temperatures caused in this species. The effects of temperature on the time and hatching rate are presented, as well as information related to embryonic development stages. After fertilization, the eggs were kept in incubators at 23, 26, 29 or 32°C and observed at predetermined times until the moment of hatching. Stages of development were identified and classified according to morphological and physiological characteristics. Oil droplets were visualized inside the eggs as well as filament adhesion present at the chorion. Embryonic development was similar to that observed in other species of the genus Melanotaenia with hatching and faster development in higher temperatures.

Description of the ontogenic and larval period of discus fish (Symphysodon aequifasciatus).

The aim of this study was to describe the embryonic and larval development of discus fish (Symphysodon aequifasciatus), and to determine the time required, hours post fertilization (hpf), for the emergence of various structures. To describe embryonic and larval stages, observations were made at regular periods under an optical microscope and images were taken with a digital camera attached to a microscope. The average temperature reached in the experimental tank was 27.9°C. Important facts in embryonic and larval development are described, such as the closure of the blastopore, which occurred at 31.5 hpf; a period of eruption, which occurred at 58.5 hpf; and a mouth opening, which occurred at 90.5 hpf; and larvae that exhibited oriented swimming and eating exogenous food at 136.5 hpf.

Morphophysiological characterization of the embryonic development of Melanotaenia praecox (Weber & de Beaufort, 1922).

Dwarf rainbowfish (Melanotaenia praecox) are an ornamental fish with a high added value and considerable commercial interest. However, little information is known about the organism's reproductive biology, especially the early stages of embryonic development (initial ontogeny). Melanotaenia praecox embryos were examined throughout development to describe the dwarf rainbowfish initial ontogeny. Eggs were incubated at 28°C, and observations were recorded at pre-determined times. Development stages were identified and classified according to morphophysiological characteristics. The initial size of the eggs ranged between 0.99 and 1.04 mm. Oil droplets were observed in the eggs, and fixing filaments for adhesion were observed in the corium. Embryonic development was similar to that of other species in the genus Melanotaenia, in which hatching begins 119.50 h post-fertilisation or 3405.75 degree-h post-fertilisation. The main features of the newly hatched larvae were excellent swimming activity, a reduced yolk sac, mouth movement and an apparently functional digestive system.