温度对墨西哥湾扇贝胚胎和幼虫发育的影响

EFFECT OF TEMPERATURE ON EMBRYO AND LARVAL DEVELOPMENT OF THE SCALLOP ARGOPECTEN IRRADIANS CONCENTRICUS SAY

于1994-1995年,在中国科学院海洋研究所贝类生态实验室,利用引自美国佛罗里达州并在我国培育繁衍的第二、三代墨西哥湾扇贝作为亲贝,采集精卵,在盐度为31—32的条件下,采用控温仪对各个设计实验温度严格控温,进行胚胎和幼虫发育的耐温实验。结果表明,墨西哥湾扇贝受精卵的有效孵化温度范围为23-30℃,其中27-28℃为最适孵化温度;D形幼虫的生存温度范围是20-32℃,当温度升至34℃时,其存活率随时间的延长而迅速下降为零。幼虫在20-33.5℃时有不同程度的生长,其中275-30℃为最适生长温度;幼虫生长的适宜温度范围在春、秋季节有所差别,春季的适温范围偏低。幼虫的最高变态率发生在28—30℃,而在234-275℃时,变态率变化不明显。当温度升至31℃后,变态率急剧下降。

F2 and F3 of the scallop Argopecten irradians concentricus Say were reproduced in China, which was introduced from Florida, USA. at the end of 1991, were utilized as broodstock.Under salinity conditions of 31-32, the eggs and sperms were collected by stimulation and were used for the experiment on temperature tolerance of the embryos and larvae. The results show that the effechve temperature range under which the fertilized eggs can hatch is 23-30℃, and the optimum range is 27-28℃. The temperature range for survival of the D larvae is 20-32℃, and the optimum, 24-28℃. At high temperature of 34℃, the survival at of the larvae falls rapidly to nought The temperature range for larval growth is 20-33.5℃, the optimum. 27.5-30℃. The growth rate of larvae is different between spring and autumn; the suitable temperature range is slightly lower in spring than in autumn. From a temperature range of 23.4- 27.5℃, the metamorphosis rate increased graclually up to a range of 28-30℃ under which it was highest and then at still higher temperature an abrupt decrease occurred.This experiment was carried out in May,1995. The aim is to determine the effects of temperature,as a monofactor, on hatching rate, survival and growth rate, and metamorphosis; the study could provide some reference data for artificial breeding. Apparently, at the early stage of embryo, the scallop is most sensitive to temperature. Thus, controlling the hatching strictly in artificial breeding would produce more and active larval. This species of scallop could tolerance high temperature and can be artificial cultured in South China Sea.