Study on refrigeration of the early larvae of the mussel Mytilus coruscus

The possibility of refrigeration(4 ℃)of early larvae of the mussel Mytilus coruscus was examined in the present study.The effect of larval density on the refrigeration of M. coruscus was also investigated in three different culture batches.After refrigeration,larvae were transferred to 18 ℃,and survival rates and shell growth of larvae were investigated.The present results showed that the average survival rates of early larvae were higher than 95%,and both shell length and shell height showed a significant increase during the 1 month refrigeration period.Larval densities of different culture batches had a different effect on larval survival and shell growth during refrigeration,indicating that larval density may be an important factor for larval refrigeration.After larvae were transferred and cultured at 18 ℃ for three weeks,survival rates of refrigerated larvae decreased to 56%,which was lower than that in control larvae(75%).In contrast,the shell growth rate of refrigerated larvae was higher than that of control larvae.Thus,refrigeration can be used as an effective method of storing larvae of M.coruscus for use in field of mollusk larval biology and improvement of seed production techniques in aquaculture industry.