Sexual and asexual production of planulae by corals from the central Great Barrier Reef

Collections of two hermatypic (zooxanthellate) species of corals (Seriatopora hystrix and Acropora palifera) and two ahermatypic (non-zooxanthellate) species of corals (Tubastrea diaphana and Tubastrea coccinea) were made between September and November, 1984 in the central Great Barrier Reef.Fragments of individual colonies were maintained in 1 litre containers of unaerated sea water at room temperature. The water was changed daily and checked for the presence of planulae, which were transferred to a separate container and kept alive for up to 7 days. Only actively swimming planulae were selected for electrophoresis. Adult tissue samples were frozen at -80°C, and tissue extracts for electrophoresis were prepared from fresh or frozen material.All adults and planulae were homogenised on cold plates (Selander RK, Smith MH, Yang SY, Johnson WE and Gentry JB (1971) Biochemical polymorphism and systematics in the genus Peromyscus. I. Variation in the old-field mouse (Peromyscus polionotus). Stud. Genet., Austin, Tex. 6, 49-90. (Univ. Tex. Publ. No. 7103). Electrophoresis was used to provide evidence of the mode of production of brooded planulae in hermatypic and ahermatypic corals from the Great Barrier Reef. Ahermatypic (non-zooxanthellate) corals were included in the study to overcome the difficulties of confirming genetic interpretations of allozyme variation due to the presence of symbiotic zooxanthellae in hermatypic species.

1984年9月至11月间，研究团队于大堡礁中部采集了两种造礁（hermatypic）且共生虫黄藻（zooxanthellate）的珊瑚物种：Seriatopora hystrix与Acropora palifera，以及两种非造礁（ahermatypic）且无虫黄藻共生（non-zooxanthellate）的珊瑚物种：Tubastrea diaphana和Tubastrea coccinea的群落样本。
将单个珊瑚群落的组织片段置于1升未充气的海水容器中，于室温下暂养；每日更换海水，并逐日检查是否存在浮浪幼体（planulae），将其转移至独立容器中暂养最长7天。仅选取活跃游动的浮浪幼体用于电泳（electrophoresis）实验。
成年珊瑚组织样本置于-80℃环境中冷冻保存，电泳所需的组织提取物则以新鲜或冷冻样本制备。所有成年珊瑚个体及浮浪幼体均在冷板上进行匀浆处理（参考文献：Selander RK、Smith MH、Yang SY、Johnson WE 与 Gentry JB (1971) 鹿鼠属的生化多态性与系统分类学。I. 旧巢鼠（Peromyscus polionotus）的变异。《遗传学研究》，德克萨斯州奥斯汀，6卷，49-90页。（德克萨斯大学出版物编号7103））。
本研究采用电泳技术，旨在验证大堡礁造礁与非造礁珊瑚的怀卵浮浪幼体产生模式。研究纳入非造礁（ahermatypic）珊瑚物种，以解决因造礁物种体内共生虫黄藻的存在，导致同工酶（allozyme）变异的遗传学解释难以验证的技术难题。