Study of nubbins growth onPorites lutea, Goniopora djiboutiensisandGalaxea fascicularisduring pre-spawn and post-spawn

Abstract

In the present study, Porites lutea, Goniopora djiboutiensis and Galaxea fascicularis were collected to evaulate the nubbins growth performance before and after ovulation under laboratory condition for period of 60 d. The results of present study indicated that there were no significant differences were observed among all treatments, and the skeleton density of coral nubbins ranged from 1. 541 to 2. 137 g / cm 3 during pre鄄spawn and post鄄spawn. Three kinds of coral growth rate exhibited relatively consistent trend, and the growth rate had significantly higher in corals of pre鄄spawn than those of post鄄 spawn. The growth rate of large鄄sized coral spikelets was significantly higher than the small size of coral spikelets during the same period, especially, there were significant difference that the growth rate of the late breeding had more significantly rapid than those in the early breeding. For Porites lutea, the marginal tissue elongation of pre鄄spawn phase had greater than those of post鄄spawn phase, moreover, for Goniopora djiboutiensis, spikelets marginal tissue elongation greater than preovulatory late ovulation. Tissue extension of pre鄄spawn Goniopora djiboutiensis nubbins was higher than that of the post鄄 spawn nubbins and that of the small nubbins was slightly higher than that of the big nubbins, but there were no significant differences. With the culture time increasing, polyp proliferation rates of Galaxea fascicularis nubbins became faster and there were significant differences in polyp proliferation numbers of different stages (P < 0. 05). However, there were no