淡水白鲳幼鱼盐碱耐受性的初步研究

Preliminary Studies on the Tolerance of Colossoma Brachypomum Fingerlings to Salinity and Alkalinity

通过淡水白鲳（ＣｏｌｏｓｓｏｍａｂｒａｃｈｙｐｏｍｕｍＣｕｖｉｅｒ）幼鱼（Ｌ＝２．９ｃｍ±０．０５ｃｍ）对氯化钠浓度（ｐＨ＝８．２１±０．０７）及碱度（ｐＨ＝８．８５±０．１８）的急性毒性试验。用概率单位法求得其２４、４８、９６ｈ的半致死浓度（ＬＣ５０）：氯化钠浓度分别为１２．０、１１．４、１０．４ｇ·Ｌ－１；碱度分别为８３．２５、５６．９９、４５．７０ｍｍｏｌ·Ｌ－１，并在此基础上进行盐碱混合正交试验，经统计分析得出碱度致死作用显著。在此条件下２４ｈＬＣ５０值时碱度与氯化钠浓度的关系为：Ａｌｋ（ｍｍｏｌ·Ｌ－１）＝２５６．２４－２４．６９Ｓａｌ（ｇ·Ｌ－１）。

This paper deals with the tolerance of Colossoma brachypomum  to NaCl and alkalinity. Through the experiment of acute toxicity, the 24, 48and 96hour median lethal concentration (LC50)values are obtained, which are 12.0, 11.4 and 10,4‰ for NaCl, and 83.25, 56.99 and 45.70mmol/l, for alkalinity respectively. Also, the mixing experiment based on the above leads to the following results: Alkalinity has a significant effect on the mortality rate of Colossoma brachypomum, and the relationship of the 24hour LC50values between alkalinity (Alk) and NaCl(S‰) is: Alk(mmol·L-1)=256.24~24.69Sal(g·L-1)(pH=8.85±0.18).