单体褶牡蛎(Crassostrea sp.)的研究

采用肾上腺素(EPI)和去甲肾上腺素(NE)诱导、颗粒固着基和先固着后脱基三种方法,对褶牡蛎的眼点幼虫进行处理,产生单体蛎苗。EPI和NE诱导的最适浓度为10~(-4)M,最适处理时间为3h,幼虫的不固着变态率分别达47.7％和46.6％。处理时间延长,变态率增加不明显。EPI和NE的诱导效果差别不明显,其诱导作用对稚贝的生长无明显副作用。颗粒固着基以贝壳粉为佳,最适颗粒的规格为幼虫的壳长。幼虫先固着后脱基而形成单体蛎苗,以可弯曲的灰色塑料板效果最好,固着的小贝可通过来回弯曲塑料板而从上面脱落下来,小贝长至1～2cm大小时,脱基最容易。

STUDIES ON CULTHLESS OYSTER, CRASSOSTREA SP

In our experiments,three methods were used to induce eycd-larvaes of oyster to be cultch-less spats:1) Using epinephrine (EPI) or norepinephrine (NE) is the induccr;2) Using particles as substrates;3) Dislodging young oysters from the attached substrates.The optimum concentration of EPI or NE was determined to be 10-4M.Near maximal induction of metamorphosis occurred with exposures as short as 3 hours,but some additional metamorphosis could be obtained with exposures of up to 24 hours.The percentages of larvae induced to metamorphose without settlement behavior or attachment after 3 hours exposure to 10-4M EPI or NE were 47.7% and 46.6%,respectively,and 59.7% and 58.0% after 24 hours exposure,respectively.In the experiment using particles as substrates,small shell chips were the best.The optimum size was determined to be about 350mm,the same as the shell length of the larvae itself.In the experiment of disloging the young oysters,the best material used as substrate was gray plastic sheet which could be flexed.Attached spat could be released by flexing the substrate slightly.It was easier to release the attached spats when they grew to 1-2cm.