膨胀蔷薇珊瑚与壮实鹿角珊瑚的胚胎和幼虫发育

摘要

Sexual reproduction of hermatypic corals is one of the approaches for coral reef restoration. This study is about sexual reproduction actions and larvae development of hermatypic corals, and it is useful for artificial coral ecosystem restoration. Corals in Luhuitou Sanya spawned between the end of March and mid April. Eggs of Montipora turgescens and Acropora robusta were collected when they were spawned in seawater during the night of llth April. The development of embryos of both species was recorded. Zygotes had cleavaged to morulas, then developed to prawn-chip shape, and then blastulae. Next,blastulae invaginated, which made blastulae plate-like shape, and then the edge bent to center, which changed blastulae to bowl-like shape. Ciliated gastrulae were formed before they became elliptic or rounded planulae. Planulae developed to coral larvae with tentacles after they settled on substrata. Zygotes of M. turgescens had fulvous zooxanthellae while they were spawned. However, zygotes of A.robusta did not have zooxanthella as they were ejected, so they took free-living zooxanthellae from seawater during the development.%造礁石珊瑚的有性繁殖是修复珊瑚礁生态系统的有效途径之一.文章为国内首次报道造礁石珊瑚有性繁殖和幼体发育过程,为利用有性繁殖技术恢复珊瑚礁生态系统提供了发育生物学上的理论基础.海南省三亚市鹿回头海域的大部分珊瑚在2009年3月底至4月中发生有性繁殖行为.2009年4月11日晚采集膨胀蔷薇珊瑚Montipora turgescens和壮实鹿角珊瑚Acropora robusta自然排放的受精卵,研究其胚胎及幼虫发育的过程.通过连续观察和显微拍摄记录了2种珊瑚的受精卵发育过程,结果显示,受精卵经过分裂变为桑葚胚;桑葚胚经过进一步发育变形为虾片状,进而发育成盘状幼体;盘状幼体由四周向内弯曲形成碗状的结构,进而出现原肠胚及纤毛,发育成为椭圆型或圆形的浮浪幼虫;浮浪幼虫发生附着变态,长出触手,发育成珊瑚幼体.通过观察还发现,膨胀蔷薇珊瑚的卵母细胞中本身就含有黄褐色虫黄藻,壮实鹿角珊瑚的卵母细胞中没有虫黄藻,其共生的虫黄藻足在发育过程中从周围环境获得的.