亲鱼密度、透明度和基质对马那瓜丽体鱼繁殖的影响

从繁殖行为学的角度研究了亲鱼密度、池水透明度、基质对马那瓜丽体鱼繁殖的影响。结果表明,在一定范围内,亲鱼密度越大,产卵率、受精率和孵化率越低。当亲鱼密度>4 RP.m-2(RP为繁殖组)时,几乎不见马那瓜丽体鱼产卵;透明度对受精率和孵化率的影响比对产卵率的影响要大。透明度越大,产卵巢间的最小距离越大;基质明显影响马那瓜丽体鱼的产卵效果。其喜欢在经过40~60目筛的砂粒上产卵,而且平均产卵率、受精率和孵化率分别达到90%、87.78%和79.44%。在棕榈皮上未见产卵,而在粗糙的瓷片上可见产卵,但其平均产卵率、受精率和孵化率明显下降,而且变动范围较大。

Effects of brood fish reproductive pairs, water transparency and ground substances on reproduction of jaguar cichlid ( Cichlasoma managuense)

From the viewpoints of ethology,this paper dealt with the effects of environmental factors,such as the number of brood fish reproductive pairs per square meter,water transparency,and ground substance on the reproduction of jaguar cichlid(Cichlasoma managuense).The results showed that to some extent,the spawning rate(SR),fertilized rate(FR) and incubated rate(IR) of C.managuense were decreased with increasing number of its reproductive pairs per square meter.The spawning activity was rarely observed when the number of reproductive pairs per square meter was higher than four.Water transparency had a greater effect on FR and IR than on SR.The greater the water transparency,the longer the shortest distance between two spawning nests.C.managuense preferred to spawn on 0.200.50 mm-sieved sand granule,with its average SR,FR and IR up to 90%,87.78% and 79.44%,respectively.No spawning activity was observed on palm husks.The fish could spawn on coarse porcelain tiles,but its SR,FR and IR decreased markedly.