澄黄滨珊瑚、大管孔珊瑚和丛生盔形珊瑚排卵前后小穗生长特征

澄黄滨珊瑚、大管孔珊瑚和丛生盔形珊瑚排卵前后分别采集珊瑚小穗,在实验室条件下进行为期60 d的养殖,观察其生长特性,结果表明:3种珊瑚排卵前后骨骼密度变化在1.541—2.137 g/cm3之间,差异不显著。3种珊瑚小穗的生长率表现出相对一致的变化趋势,同一规格珊瑚小穗排卵前期生长率明显高于排卵后期;同一时期大规格珊瑚小穗生长率明显高于小规格珊瑚小穗,而且养殖中后期生长较快,养殖前期生长较慢,差异显著(P0.05)。澄黄滨珊瑚小穗边缘组织延伸度排卵后期大于排卵前期,大管孔珊瑚小穗边缘组织延伸度排卵前期大于排卵后期,以上两种珊瑚的小规格珊瑚小穗与大规格珊瑚小穗组织延伸度相当。随着养殖时间的持续,丛生盔形珊瑚小穗螅体增殖速率加快,各养殖阶段螅体数差异显著(P0.05),珊瑚小穗规格和养殖季节对其小穗螅体增殖数量没有显著影响。3种珊瑚小穗生长指标间多呈显著正相关,仅大管孔珊瑚小穗初始直径、初始重量与组织延伸度间,以及丛生盔形珊瑚小穗初始重量与初始螅体数量、生长率间相关性不明显。

Study of nubbins growth on Porites lutea, Goniopora djiboutiensis and Galaxea fascicularis during pre-spawn and post-spawn

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/cm³ during pre-spawn and post-spawn. Three kinds of coral growth rate exhibited relatively consistent trend, and the growth rate had significantly higher in corals of pre-spawn than those of post-spawn. The growth rate of large-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-spawn phase had greater than those of post-spawn phase, moreover, for Goniopora djiboutiensis, spikelets marginal tissue elongation greater than preovulatory late ovulation. Tissue extension of pre-spawn Goniopora djiboutiensis nubbins was higher than that of the post-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 significant differences between polyp size of proliferation numbe and culture season. Significant positive correlations of all growth index of nubbins among three coral species were obtained, however, there were no correlations between initial diameter and/or weight and tissue extension of Goniopora djiboutiensis nubbins, and there were no correlation between initial weight/polyp number and growth rates of Galaxea fascicularis.