温度、饵料种类对中华哲水蚤(Calanus sinicus)油脂积累与生长发育的影响

EFFECT OF TEMPERATURE AND FOOD ON LIPID ACCUMULATION IN CALANUS SINICUS(COPEPODA: CALANOIDA

中华哲水蚤(Calanus sinicus)C5期幼体的油脂积累是种群在黄海冷水团中得以顺利度夏的关键过程。本研究对温度(10°C和19°C恒温,10—19°CⅠ和10—19°CⅡ变温)与饵料种类(硅藻饵料,自然饵料)双因子培养实验进行研究,探讨温度和饵料种类对中华哲水蚤油脂积累与生长发育的影响作用。结果表明,不同的温度和饵料种类对C5期幼体的油脂积累均有影响。C5期幼体在变温组的油脂积累是10°C组的31%—102%,是19°C组的1.8—6.1倍,低温有利于C5期幼体降低个体代谢消耗以增加油脂的积累。在恒温培养下,C5期幼体在硅藻饵料组的油脂积累是自然饵料组的2.8倍,硅藻饵料比自然饵料更有利于油脂的积累。雌体的体长和油囊体积均随着温度的升高而减小。与硅藻饵料相比,在自然饵料组中雌体的性腺发育速度更快,性腺成熟度更高(繁殖指数:58%—65%)。

Lipid accumulation in C5 copepodite stage（C5s） of Calanus sinicus is a key process for the success of over-summering in the Yellow Sea Cold Water Mass. We cultured C. sinicus in different temperature-food type combinations. Temperatures were set in four schemes（10℃, 19℃, 10—19℃ I（12h（10℃）：12h（19℃）, temperature rose up or decreased in 2 h）, and 10—19℃ II（the same to the Scheme 10—19℃ I but rose up or decreased in 12 h） in two food types（diatom and natural diets） to observe their effect on lipid accumulation and development of C. sinicus. Result shows that the lipid accumulation at C5 s stage was strongly affected, i.e., the lipid accumulation at changing temperature was 31%—102% of that at 10℃, and 1.8—6.1 times of that at 19℃. Lower temperature could benefit lipid accumulation by saving energy cost via respiratory metabolism. In constant temperature and diatom food type, the lipid accumulation of C5 s was 2.8 times over that in natural diet. Therefore, diatom could benefit lipid accumulation. Moreover, the prosome length and oil sacs of females reduced as temperature increased. Compared to diatom diet, the gonad development in female fed with natural diet was faster, with higher reproductive index（58%—65%）.