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.