Species records and distribution of shallow-water coralline algae in a Western Indian Ocean coral reef (Trou d'Eau Douce, Mauritius)

Abstract

Seventeen taxa of coralline algae were identified in different reef environments on the eastern coast of Mauritius. Nine of these are reported from this island for the first time: Amphiroa rigida Lamouroux var. antillana B0rgesen, Amphiroa tribulus (Ellis et Solander) Lamouroux, Choreonema thuretii (Bornet) Schmitz, Jania capillacea Harvey, Jania pumila Lamouroux, Jania ungulata (Yendo) Yendo, Lithophyllum pallescens (Foslie) Foslie, Mesophyllum erubescens (Foslie) Lemoine and Sporolithon ptychoides Heydrich. Data concerning habitat and geographical distribution of the species are presented. Coralline algae are widely distributed in Trou d'Eau Douce reefs, being a group of organisms of major importance in the structure of reef communities. Geniculate coralline algae are common in algal turfs growing on cobbles, dead corals or as epiphytes on larger brown algae. Non-geniculate species are dominant, both in rhodolith beds from shallow lagoon waters in sheltered areas, and in the much exposed reef flat. Hydrolithon onkodes (Heydrich) Penrose et Woelkerling, Lithophyllum tamiense Heydrich and Lithophyllum kotschyanum Unger are the most abundant species on hard substrata while Mesophyllum erubescens dominates in rhodolith beds.