白棘三列海胆苗种繁育及盐度对受精、胚胎和幼体发育的影响OA

To develop aquaculture resources for Tripneustes gratilla(white-spined sea urchin)in China,this study aimed to improve the breeding process for this species.The fertilization,embryo,and larval development processes were observed,and the effects of salinity changes on fertilization,embryo,and larval development were also preliminarily explored.The results are as follows:1)Through artificial insemination,the fertilization rate reached 91.4%.The embryonic development process included the multicellular stage,blastula stage,and gastrula stage,with a hatching rate of 69.2%.Going through multiple stages of breeding,1.5×106 prism larvae develop into four-arm larva,and 1×106 four-larvae develop into to eight-arm larvae,lasting for approximately 50 days,and finally cultivated the juvenile sea urchins of metamorphosis;2)At salinity levels of 30-40,the fertilization rate of T.gratilla exceeded 80%,significantly higher than that in the low salinity groups(20 and 25)(P＜0.05).The best fertilization and hatching performance were observed at 35 salinity.When salinity fell below 25,fertilization rates declined,hindering subsequent development,with no fertilization occurring at 20.The suitable salinity range for the arm larval stage is 35-40;larval growth was better at 35 than at 40,but the survival rate of larvae was sig-nificantly higher at 40 than at 35(P＜0.05).In summary,this study systematically observed the developmental process of T.gratilla and explored the effects of salinity on larval development.The data obtained can provide support for artificial breeding and large-scale aquaculture of sea urchins.