A dinoflagellate symbiont of the coral Oculina diffusa Lamarck (Cnidaria: Anthozoa)




Gouldy, R.R.

Journal Title

Journal ISSN

Volume Title


Texas A&M University.


Oculina diffusa Lam. was collected from three sites along the Texas coast. The algal symbiont of this coral was studied directly from the living tissues of the coral and from isolations of the alga in three different media maintained at different culture regimes involving variations of temperture, photoperiod, and light intensity. Histochemical tests were performed on both cultured algae and cells taken directly from the coral tissues. Observations on the life cycle of the alga were recorded. Morphological, histochemical, and life cycle observations were also made on the algal symbionts which have been identified as Gymnodinium microadriaticum in two corals from the Florida Keys. The life cycle of the Oculina symbiont is very similar to the observed and reported life cycle of G. microadriaticum. However, consistent differences in size and in internal morphology of the symbiont from O. diffusa are convincing. This organism must be examined further by cultured and ultrastructural methods to determine its affinity to G. microadriaticum.


39 p., Thesis


symbiosis, symbionts, hosts, Oculina diffusa, algae, Gymnodinium microadriaticum, life history, organism morphology