连阴雨天气对凡纳滨对虾-吉丽罗非鱼混养围隔中浮游植物和对虾生长、存活的影响

目的]为凡纳滨对虾-吉丽罗非鱼混养提供一定的理论依据。方法]探讨连续阴雨天气对凡纳滨对虾养殖围隔中浮游植物和对虾生长、存活的影响。结果]连阴雨天气对围隔中浮游植物的数量和优势种都有影响,使各围隔浮游植物数量下降,在7月20日降至最低,优势种从蓝藻转变为绿藻。连续阴雨天气使半数围隔在7月10日左右出现了死虾情况;7月10日至7月23日各围隔pH、溶解氧均有所降低,氨氮和亚硝酸盐含量有所上升,这些环境因子的突变不利于对虾的生长。结论]连阴雨天气通过影响浮游植物和水体温度、pH、氨氮、亚硝氮等理化因子,引起的养殖水体环境波动,从而导致对虾病害的发生。

Effects of Continuous Rainy Weather on Phytoplankton and the Growth and Survival of Shrimp in Litopenaeus vannamei-Gili Tilapia Polyculture Enclosures

Objective] The research aimed to provide some theoretical basis for Litopenaeus vannamei-Gili tilapia polyculture.Method] The effects of continuous rainy weather on the growth and survival of phytoplankton and shrimp in the culture enclosure of L.vannamei were studied.Result] The continuous rainy weather had the effects on the number and dominant species of phytoplankton in the enclosures.The number of phytoplankton in all enclosures declined and reached the lowest value on July 20th,and the dominant species changed from Cyanobacteria to Chlorophyta.Because of continuous rainy weather,dead shrimps appeared in half of enclosures on about July 10th.From July 10th to July 23rd,pH and dissolved oxygen in the enclosures decreased,and the content of ammonia nitrogen and nitrite increased.The changes of these environmental factors were harmful to the growth of shrimp.Conclusion] Continuous rainy weather influenced the temperature,pH,ammonia nitrogen,nitrite nitrogen and other physical and chemical factors of phytoplankton and water,which caused the environmental fluctuations of aquaculture water and resulted in the occurrence of shrimp diseases.