Diversity of Seaweeds and Seagrasses of St. John’s Island, Singapore

Abstract

The species diversity of seaweeds and seagrasses of St. John’s Island, Singapore was investigated by snorkeling during 5–7 October 2010. The specimens were collected from intertidal level seawards. Seventy-seven species in 50 genera and 29 families were reported, of which 2 species are blue-greens (Cyanophyta), 26 species are greens (Chlorophyta), 15 species are browns (Phaeophyceae) and 34 species are reds (Rhodophyta). Ten species of seaweeds are new records for the algal flora of Singapore: Ulva rigida C. Agardh, Caulerpa microphysa (Weber-van Bosse) Feldmann, Chlorodesmis caespitosa J. Agardh, Spatoglossum schroederi (C. Agardh) Kützing, Jania ungulata (Yendo) Yendo, Hypnea cornuta (Kützing) J. Agardh, Gracilaria chondracantha (Kützing) Millar, Antithamnionella breviramosa (Dawson) Wollaston Gayliella fi mbriata (Setchell et Gardner) Cho et Boo and Anotrichium tenue (C. Agardh) Nägeli. Three species of seagrasses, Halophila minor (Zollinger) den Hartog, Halophila ovalis (Brown) Hooker and Thalassia hemprichii (Ehrenberg) Ascherson were also present.