Vol. 46 No. 6, 2007

Distribution Patterns of the Renieramycin-Producing Sponge, Xestospongia sp., and Its Association with Other Reef Organisms in the Gulf of Thailand

Udomsak Darumas^1,3,*, Suchana Chavanich¹, and Khanit Suwanborirux²

¹Department of Marine Science, Faculty of Sciences, Chulalongkorn University, Pathumwan, Bangkok 10330, Thailand
²Center of Bioactive Natural Products from Marine Organisms and Endophytic Fungi (BNPME), Department of Pharmacognosy, Faculty of Pharmaceutical Sciences, Chulalongkorn University, Pathumwan, Bangkok 10330, Thailand
³School of Biology, Institute of Science, Walailak University, Thasala, Nakhorn Si Thammarat 80160, Thailand

Udomsak Darumas, Suchana Chavanich, and Khanit Suwanborirux (2007) The renieramycin-producing sponge, Xestospongia sp., is a coral reef inhabitant occurring in the Gulf of Thailand. The distribution patterns of Xestospongia sp. and its association with other organisms were investigated, with results showing that the most frequently coexisting organisms were the massive coral, Porites lutea, and the colonial zooanthid, Palythoa caesia, but it also inhabited algal patches and dead coral rubble. The largest individuals of Xestospongia sp. were found growing on Pa. caesia while the smallest individuals were found on algal patches. The results also showed that concentrations of renieramycin M, the main alkaloid with highly potent cytotoxicity, extracted from this sponge differed significantly among sites (p < 0.05).

Key words: Xestospongia sp., Renieramycin concentration, Coexisting organisms, Gulf of Thailand.

*Correspondence: Tel: 66-7-5672043. Fax: 66-7-5672004. E-mail:dudomsak@wu.ac.th or dkhundodo@yahoo.com