Culture studies on two morphological types of Caulerpa (Chlorophyta) from Perth, Western Australia, with a description of a new species

The phenotypic plasticity and performance of two growth-forms of Caulerpa racemosa (Forsskal) J. Agardh, one found in estuarine conditions, the other growing in a coastal reef environment was studied in laboratory culture. There was no change in the morphology of either growth-form when cultured through a range of salinity (10—40%o) and light (20—140 μEm-2s-1) conditions. The estuarine growth-form performed better than the coastal one in low salinities (20%o), which suggests physiological adaptation to the estuarine environment. It was concluded that differences in morphology of both types were fixed rather than plastic. The taxonomic status of the estuarine growth-form was raised from a phenotypic variant of C. racemosa (Forsskal) J. Agardh to a new species, Caulerpa lagara sp. nov.

Keywords: