Effects Of Salinity On Embryonic Development And That Of Two Different Attachment Substances In Juvenile Stage Of Argopecten Irradians Concentricus

In this study the experiment was carried out to study the effect on embryonic development,fertilization rate and hatching rate of new strain of Argopecten irradians concentricus under different salinity(17,21,25,29,33)at 27-29?,and attaching effect of using polyethylene network film and attachment plate during settlement stage was compared.The main contents were as follows:1.Different salinity impact on embryonic development of A.irradians concentricusIn this study,the experiment was conducted to understand the different salinity on the embryonic development of A.irradians concentricus.The results showed the embryo development of A.irradians concentricus was the fastest at the temperature 28? and the salinity 25.After fertilized about 22 h,D-shaped larvae was formed,and the fertilization rate of this species increased with salinity(17,21,25,29,33).The fertilization rate was decreased with increasing salinity until the salinity reached 25.Additionally,the hatching rate of A.irradians concentric increased with increasing salinity under the salinity of 17-25,while that of this species decreased with increasing salinity from 25 to 33.In words,different salinity had little effect on the embryonic development of the new strain of A.irradians concentricus at the temperature 28-30? and salinity 17-33.The suitable salinity for cultivation of this new strain was from 17-33.Finally,the embryo development time was the shortest when the salinity was 25,the fertilization rate and hatching rate were the highest.2.Compared the attachment efficiency of polyethylene network film and attachment plate during the juvenile stageIn the present study,the results of regression analysis of the growth of A.irradians concentricus juvenile indicated a linear relationship between the shell length and the shell height in the upper,middle and lower layers on polyethylene network film and attachment plate.The growth of juveniles of A.irradians concentricus was analyzed by several factors:shell length,shell height,daily growth rate,shell length and daily growth rate.The results reflected the middle layer of the polyethylene network film and attachment plate was the best site for A.irradians concentricus juvenile cultivation.The growth of juveniles on polyethylene plate was slightly better than that on polyethylene network film,but the difference was not significant(P>0.05).Besides,through observing the attachment time,variability rate,adhesion density,and survival rate of juveniles,we found that there were significant differences in the adherence time,variability rate and juvenile survival rate of polyethylene network film and that in adhesion density of the attachment plate as well(P<0.05).The adhesion effect of the same attachment substance showed:upper layer>middle layer>lower layer,but the growth of juveniles on the two different attachment substance showed no significant differences.