Comparison of early development, metamorphosis, growth and intestinal microbiota in different families of Heliocidaris crassispinas

In order to compare the differences of larva growth and development among different families of Heliocidaris crassispinas, 9 full-sibling families of H. crassispinas were constructed. The important indicators of larval growth and development, including fertilization rate, hatching rate, larva survival rate, metamorphosis rate and initial feeding rate, were compared in the 9 families. The results showed that the fertilization rate of every family was over 95%, without no significant difference (P>0.05), but there are significant differences in other indicators in 9 families (P<0.05). The highest hatching rate, early larval survival rate, late larval survival rate, metamorphosis rate and nitial feeding rate are family No.3 (58%), family No.1 (83%), family No.4 (90%), family No.2 (75%) and family No.9 (100%), respectively, and the lowest are family No. 6 (0%), family No.3 (42%), family No.2 (76%), family No. 9 (6%) and family No.5 (24.5%), respectively. The growth rate of family No. 3 is 146%, which is the fastest in all families. While, the slowest one is No.5 families (76%). At the end of the experiment, the gonad development of family No.3 was obvious; the other families were not, yet. The Proteobacteria proportion of family No.3 is high, but Bacteroidetes proportion is low. The proportion of the two phyla of family No.5 is opposite to that of family No.3.The results show that there are differences in production traits among different families of H. crassispinas, which has the potential for breeding and improving, and this study accumulate relevant data for the cultivation of H. crassispinas.