Embryonic And Development Of Purple Sea Urchin Anthocidaris Crassispina

The experiment studies on the technique of artificial breeding and ecophysiological effect of microalgal and illumination on sea urchin Anthocidaris crassispina larvae was undertaken.And then,a series of microcrosmio teohnique was conducted to investigate the development of embryonic,the effects of microalgal on the growth,development and survival of larvae sea urchin and the effects of light intensity on the activities of protease,amylase and lipase activities.The aim of this study was to investigate the effects of microalgal and light on the growth and development of sea urchin Anthocidaris crassispina embryonic and larvae sea urchin Anthocidaris crassispina.The main results are detailed as follows:1.At temperature of(29.7±0.48)?,it took a total of 22 d for fertilization eggs to develop into eight-armed larvae stage.The time of each stage was different and there were significant morphological differences.The embryonic and larval development of Anthocidaris crassispina can be divided into the following stages: fertilization egg,cleavage,blastula,gastrula,prism larvae,two-armed larvae,four-armed larvae,six-armed larvae,eight-armed larvae,and juvenile.Among them,early embryo developed quickly,and the whole process last about 12 h.The time from the prism larval stage to the two-armed larvae stage was the shortest,about 2 h.The prism larval stage went into two-armed larvae stage in 17 h,and went into four-armed larvae stage in 1 d 7 h,went into six-armed larvae stage in 5 d,went into eight-armed larvae stage in 8 d.2.This study investigated the growth and survival of sea urchin Anthocidaris crassispina larvae fed six microalgal diets,i.e Dicrateria zhanjiangensis,Chaetoceros gracilis,Pavlova viridis,Platymonas subcordiformis,Chlorella vulgaris,and mixture of C.gracilis and D.zhanjiangensis(1:1).The result indicated that Dicrateria zhanjiangensis was the optimum microalgal diet for the survival of A.crassispina larvae.Chaetoceros gracilis,Pavlova viridis,Chlorella vulgari,and mixture of C.gracilis and D.zhanjiangensis are suitable for the sea urchin larvae rearing.However,the P.subcordiformis was not an ideal microalgae diet for sea urchin larvae.The microalgal mixture is the best feed for the development of sea urchin larvae.The growth rate of pelagic larvae fed P.viridis was slower in the early stage and faster in the eight-armed larvae than that feed of other mono-cellular algae.Therefore,the P.viridis is suitable for the eight-armed larvae.This experiment aims to screen suitable microalgal diets that are capable of improving growth rate of A.crassispina larvae and provide certain reference for the sea urchin cultivation.3.The effects of different light intensities(0 lx,500 lx,1000 lx,2000 lx,3000 lx)on larvae growth and enzyme activity of sea urchin Anthocidaris crassispina.The results showed: the effects of light intensity on the larval length,body-rod length and post-oral arm of sea urchin larvae had similar changing trend.The growth velocity under different illumination intensities were as followed: 500 lx >0 lx>1000 lx>2000 lx>3000 lx.The larvae length,body-rod length and post-oral arm of sea urchin in 500 lx treatment was the highest among all the light intensity treatments(P<0.05).In the 9th,the larvae had all died in 3000 lx treatment,and the 500 lx treatment had the highest survival rate.The maximum activity of amylase and lipase was in 500 lx treatment while the maximum activity of protease was in 2000 lx treatment.