[Objective]The research aimed to provide theoretical basis for scientific application of isomaltose hypgather in the breeding of Megalobrama terminalis. [Method] Different levels of isomaltose hypgather were added in the basic feed of M. terminalis to study the growth of M. terminalis and the number and composition of intestinal beneficial bacteria. The effects of isomaltose hypgather on the intestinal microflora of M. terminalis were discussed. [Result]Adding 0. 3% and 0. 6% isomaltose hypgather in the basic feed could significantly enhance the survival rate of M. terminalis. Adding 0. 6% and 0. 9% isomaltose hypgather could significantly promote the growth of M. terminalis. Adding 0. 6% and 0. 9% isomaltose hypgather could significantly increase the amount of Bifidobacterium spp. and Lactobacillus spp. in the intestine of M. terminalis and improve the polymorphism of intestinal microflora to some extent. [Conclusion] The increase of the survival rate of M. terminalis was related with improving the intestinal bacterial composition and increasing the growth of beneficial bacteria to some extents.

[目的]确定苯甲酸雌二醇诱导黄颡鱼性转化的条件.[方法]分别以浮游动物和微颗粒饲料作为激素载体,研究了添加不同浓度的苯甲酸雌二醇对黄颡鱼性转化诱导过程中成活率、雌性率以及体长的影响.[结果]浮游动物与微颗粒饲料作为载体进行投喂对黄颡鱼鱼苗成活率、雌性率和体长具有较明显差异,浮游动物组成活率为43.1％ ～66.5％,而微颗粒饲料组成活率为17.1％ ～52.1％;过高的激素浓度处理会导致死亡率升高,而过低的激素浓度处理会导致雌性率大大降低;不同载体和激素处理浓度对黄颡鱼鱼苗生长均具有明显的抑制作用.[结论]以浮游动物或微颗粒饲料为载体,苯甲酸雌二醇的最适浓度分别为150 μg/L和50 mg/kg.

We have measured several biological indices for 12 female samples of Acrossocheilus fasciatus collected random, like the body length(L), body weight(W), net body weight(Wn) and gonad weight(Wo) ect. We have counted the individual absolute fecundity by mass method, then calculated the body length relative fecundity(FL), body weight relative fecundity(Fw) and mature coefficient. The results showed that the individual absolute fecundity(F) was from 458 to 14 254 eggs, 3 736 eggs on average; the body length relative fecundity(FL) was from 50 to 1013 eggs per centimeter, 346 eggs per centimeter on average; the body weight relative fecundity(Fw) was from 19 to 151 eggs per gram, 85 eggs per gram on average. It also indicated us that the absolute fecundity was mainly concentrated from 1 000 to 5 000 eggs and there were rare samples over 10 000 eggs, as well as the body length relative fecundity was mainly distributed from 100 to 500 eggs per centimeter while the body weight relative fecundity was mainly concentrated from 25 to 100 eggs per gram.

<正>近几年来,泥鳅的需求量不断增大,出口订单络绎不绝,成为我国出口创汇的良好鱼种。为应对不断增长的需求,提高泥鳅的苗种成活率从而达到增产目的的研究就刻不容缓了。一、亲鳅的选择与培育1.亲鳅的挑选挑选无病无伤、体质健壮和性腺发育良好的泥鳅,作为繁殖的亲本。泥鳅雌雄个体主要通过外部形态来区分,雌鳅

采用特异性引物PCR扩增获得了河川沙塘鳢细胞色素b基因序列，并与塘鳢科其余22种细胞色素b基因序列进行比对，运用Mega3．1软件通过NJ法构建了塘鳢科鱼类系统发育树。结果显示：两尾试验鱼构成一支，Eleotris、Hypseleotri两属构成一支，Odontobutis、Perccottusglehni两属构成一支，Bostrychus、Butis、Oxyeleotris、Ophiocara四属构成一支，Ptereleotris heteroptera单独构成一支。本研究结果可为深入探讨沙塘鳢属及塘鳢科鱼类的系统分类与重新整理提供依据。