科研之友
微信
新浪微博
Facebook
分享链接
摘要
O objetivo deste trabalho foi avaliar a tolerancia de larvas de pacam Lophiosilurus alexandri ao teste agudo de salinidade da 芍gua em diferentes idades. Os testes foram realizados em larvas rec谷m-eclodidas, com oito e 12 dias p車s-eclos o. As larvas foramaclimatadas 角s condi es experimentais por 24h, sendo estocadas em 18 tanques pl芍sticos de 1 L na densidade de 15 larvas L-1. Ap車s esse per赤odo, as larvas foram transferidas para as salinidades: 芍gua doce, 2, 4, 6, 8 e 10 g de sal L-1 e observadas durante 96h. Larvas rec谷meclodidas apresentaram mortalidade total em 6, 8 e 10 g de sal L-1 e 100% de sobreviv那ncia para 芍gua doce, 2 e 4 g de sal L-1; por谷m, com redu o dos valores de peso e comprimento mediante as duas salinidades. Larvas com oito dias p車s-eclos o apresentaram CL(I)50-96h de 8,9 g de sal L-1. Para o peso, verificou-se redu o gradativa a partir da salinidade de 2 g de sal L-1, mas sem diferen as para o comprimento das larvas entre os tratamentos. Para as larvas com 12 dias p車s-eclos o, n o se registraram diferen as no comprimento e peso e a sobreviv那ncia foi menor a 8 e 10 g de sal L-1. Larvas com oito e 12 dias p車s-eclos o tiveram altera es no comportamento natat車rio em salinidades superiores a 6 g de sal L-1. Larvas de pacam apresentaram maior tolerancia 角s diferentes salinidades da 芍gua com o desenvolvimento ontogen谷tico. The aim of this study was to analyze the salinity tolerance of ※pacam § Lophiosilurus alexandri larvae at different ages. The test was conducted in post-hatching-larvae and larvae with 8 and 12 daysold post-hatching. Larvae were acclimatized to experimental conditions for 24h, kept in 18 plastic tanks with 1 L at a density of 15 larvae L-1. After this period, larvae were subjected tothe salinities: freshwater, 2, 4, 6, 8 and 10 g salt L-1, and observed over a period of 96h. Posthatching larvae exhibited complete mortality in 6, 8 and 10 g salt L-1. Survival was 100% infreshwater, 2 and 4 g salt L-1 每 although with the decrease in weight and length values to the salinities of 2 and 4 g salt L-1. The CL(I)50-96h of larvae 8 days old post-hatching was 8.9 g saltL-1. The weight was diminished with the increase in salinity, but no difference was registered in length between the different treatments. Larvae 12 days old post-hatching did not show differences in length and weight. The survival was lower in 8 and 10 g of salt L-1.Larvae 8 and 12 days old post-hatching changed their swimming activity behavior to saline water up to 6 g of salt L-1. ※Pacam § larvae showed higher tolerance to the different salinitieswith larval dev
