Effect of temperature on the embryonic and larvae development of discus fish Symphysodon aequifasciatus and time of first feeding.

This study aimed to analyze the influence of different temperatures on the embryonic and larval development of discus fish Symphysodon aequifasciatus and determine the time required for the beginning of exogenous feeding. Eggs and larvae were obtained from natural spawns and distributed in five treatments: 24.0, 26.0, 28.0, 30.0, and 32.0 °C. To assess the developmental stages and embryonic structures, samples were taken at regular intervals and checked under an optical microscope. At the end of the experimental period, statistical analysis was performed, followed by Tukey's test. As a result, it was possible to observe the significant effects of temperature on the variables. It was noted that the temperature accelerated the embryonic and larval development of the discus and also contributed to a reduction in the time between the incubation period and the feeding transition. It was also noted that the incubation of eggs and larvae at a temperature of 24.0 °C can cause damage to embryos, such as malformation of the body as well as anomalies in the circulatory system.

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.