Abstract:
Marine sponges (Order Haplosclerida, Phylum Porifera) in coral reefs along the Eastern coast of Thailand were collected from two types of habitats; coral reef flats and coral reef slopes, of 30 islands in Chonburi, Rayong, Chontaburi and Trad from November 2003 to July 2005. From this study four familles of sponge were found i.e.; Chanilidae, Niphatidae, Petrosildae and Phloeodichtyidae. The most abundant species of sponges found in this study belonged to the genus Haliclona of the family Chalinidae, but Haliclona (Reniera) sp.; white in color, and Haliclona (Gellitus) cymaeformis were the least abundant species. Gelliodes petrosioides of the family Niphatidae was the most abundant species on the reef flats while Xestospongia testudinaria (family Petrosiidae) was the most abundant species on the reef slopes. Of these two types of habitats, Xestospongia testudinaria covered the largest area whereas Gelliodes petrosioides was in the second place. In addition to this, sponge coverage areas was larger on the coral reef slopes in comparison to those of the coral reef flats. Aka mucosa (family Phloeodichtyidae), however, was not presented on the coral reef slopes. Chalinula sp. (blackish purple in color) was an endemic species to Koh Man, Rayong province. There was no evidence showing specific differentiation between these two studied habitats. There were, however, six species of marine sponges having relationships with benthic life forms, i.e.; Haliclona (Gellitus) cymaeformis with living corals in which having inverted reationship with Dasychalina melior (p<0.05). Dead corals would have inverted relationship with Neopetrosia sp. (blue in color) (p<0.01) and they would also be related to Petrosia (Petrosia) hoeksemai (family Niphatidae) (p<0.05). Haliclona (Haliclhoclona) amboinensis would have relationship with rocky habitats (p<0.01) while Xestospongia testudinaria would have inverted relationship with the sand-habitaus.