Effects of larval cryopreservation on subsequent development of the blue mussels, Mytilus galloprovincialis Lamarck

摘要

In this study, the effects of three commonly used chemicals, dimethyl sulphoxide (DMSO), ethylene glycol (EG), propylene glycol (PG) and their combinations with trehalose, were evaluated on the cryopreservation of D-larvae of the blue mussel Mytilus galloprovincialis. The larvae were harvested 30?h post-fertilization at 21?°C and cryopreserved using a standard protocol in 5%, 10% or 15% of DSMO, EG and PG either as single chemical solutions or in combination with 0.2?M trehalose. Among these cryoprotectants, 5% DMSO resulted in the highest post-thaw survival rate of 55.3±7.8%, although it did not significantly differ from those with 10% and 15% EG. The addition of 0.2?M trehalose did not improve the post-thaw larval survival rates in all the combinations assessed. The cryo-effects on subsequent development were evaluated using the D-larvae frozen with 5% DMSO. The results showed that cryopreservation affected both larval survival and growth in this species. The relative daily mortality rate was significantly higher in treated than control groups over the period from 3?h post-thaw to day 11 post-fertilization. On day 6 post-fertilization, the average larval length in the treated group was significantly smaller than that in the control. From day 11 post-fertilization, and onwards, differences in these two traits were not significant between treated and control groups. On day 21 post-fertilization, about 80% of the larvae in both treated and control groups developed eyes and the normalized survival rate in the treated group was 12.5%.