Species diversity, biomass and community structure of cephalopods off Adang-Rawi Archipelago, Thailand

The cephalopod fauna off the off Adang-Rawi Archipelago, Thailand, and adjacent areas, was investigated between December 1998 and April 1999 during the northeast monsoon season. Four families of cephalopods were found, namely Loliginidae (Loligo duiauceli, L. chinensis, Loliolus sumatrensis and Sepioteuthis lessoniana), Sepiidae (Sepiella inermis, Sepia aculeata, S. phuraonis, S. lysidas, S. brevimana and S. recurvirostra), Sepiolidae (Euprymna stenodactyla), and Octopodidae (Octopus spp.). The average catch rate and biomass were 4.34 kg h -1 and 320.66 t, respectively. The highest catches were in February (5.32 kg h -1 ; 382.57 t), December (4.10 kg h -1 ; 314.33 t) and April (3.61 kg h -1 ; 265.07 t). Diversity measures were applied and three assemblages recognized, i.e., the western side of Tarutao Island, north and south of AdangRawi Archipelago. Salinity was the best-fitting environmental parameter and correlated with biotic pattern in the survey area.