接种密度、食物量及温度对萼花臂尾轮虫(Brachionus calyciflorus)种群增长的影响

Effects of Initial Population,Food Quantities and Temperature on Population Growth of Brachionus calyciflorus

萼花臂尾轮虫(Brachionus calyciflorus)是淡水仔鱼的理想开口饵料,许多环境因子对其生长繁殖都有影响。研究了不同接种密度、不同食物量、不同温度对萼花臂尾轮虫种群生长的影响。接种密度选择5、15、20、35个/mL等4个梯度;食物量选择每日每百万只1、5、10g酵母3个梯度;温度选择20、25、30、35℃等4个梯度。结果表明:1)利用干酵母培养萼花臂尾轮虫时,接种密度每20个/mL左右为宜:密度过低时,种群很难适应新环境;密度过高时,平均增长率低下;2)每日每百万只5g酵母比其它食物量更适合萼花臂尾轮虫种群的增殖:食物量过低,生长慢,个体小;食物量过高时,水体污染严重;3)30℃萼花臂尾轮虫大量快速增殖:温度低于30℃繁殖缓慢;温度高于30℃无法生存。

Brachionus calyciflorus is the great starting food to freshwater larval. There are many environment factors effecting their growth and increase. The different initial population densities, food quantities and temperature of Brachionus calyciflorus cultured under different conditions are studied in this paper. Initial population densities are chosen from 4 grads： 5, 15, 20 and 35 individuals per mL ; food quantities are chosen from 3 grads ： 1 g of yeast for a hundred million individuals of rotifer per day, 5 g of yeast for a hundred million individuals of rotifer per day, 10 g of yeast for a hundred million individuals of rotifer per day; temperatures are chosen from 4 grads： 20,25,30 and 35 ℃. The results show as follow： 1 ） about 20 individuals per mL of initial population densities is the optimum density for rotifer with yeast in this experiment. The population can not adapt the new environment in lower initial population densities. The average increasing rate is lower in higher initial population densities. 2） 5 g of yeast for a hundred million individuals of rotifer per day is more suitable than other food quantities for the population. The rotifers grow slowly and the body size is small in lower food quantities. The water is polluted seriously in higher food quantities. 3 ） The growth of Brachionus calyciflorus is better at 30 ℃ ; the rotifers breed slowly when temperature is lower than 30 ℃ ; and they can not live when the temperature higher than 30℃.