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 duvauceli, L. chinensis, Loliolus sumatrensis and Sepioteuthis lessoniana), Sepiidae (Sepiella inermis, Sepia aculeata, S. pharaonis, 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 Adang-Rawi Archipelago. Salinity was the best-fitting environmental parameter and correlated with biotic pattern in the survey area

Fishing status of Thailand

Marine fishery of Thailand characterized as multi-species and multi-gear fishery. The continuous advances in fishing technology make marine production increasing annually that resulted in depletion of the stocks particularly in the Gulf of Thailand. Most of economically important species has been reported as overexploited or fully exploited. Approximate 90% of marine catch come from large scale fisheries. Trawlers, purse seines, drift gill nets, encircling gill nets regarded as important fishing gears practice. In 1994, total marine production (capture and culture) was 3,150,233 ton, comprised pelagic fish 953,907 ton, demersal fish 287,940 ton, miscellaneous fish 172,591 ton, crustaceans 437,508 ton, mollusk 281,611 ton, trash fish 930,546 ton and others 86,112 ton. The demersal resources are mostly caught by trawl net while pelagic caught mainly by purse seines and gill nets. Among these, trash fish accounted for 40% of total catch, of which more than 30% of the trash is juvenile and unsized economic fish. The major catch of trash fish comes from otter board trawl 75%, pair trawl 15%, purse seines 8%, push net 1%, and the rest is from other gears. The Department of Fisheries has implemented the strategy for responsible fisheries management and development on the basis of conservation and long-term sustainable fisheries in which environmental and ecological management is also taken into account. Fishery's regulations and notification are imposed on a fishery to achieve management and conservation objectives. The regulations that protect particular parts of the stocks are minimum mesh size to protect small individuals, closed season and area to protect juvenile and spawning stock, the restriction of the use of certain type of fishing and methodology in certain area. Other approaches are minimize number of fishing trawl vessel, ban the push net, developments of fishing gear selectivity to reduce by-catch and discard fish, installation of artificial reefs to restore the sea, encourage public awareness in using the resources. Besides government have established two committees, the National Fisheries Policy Committee and the National Committee of the Thai Sea Rehabilitation Program to be responsible for fishery and fishery-related activities

Phylogeny of the Sepia pharaonis species complex (Cephalopoda: Sepiida) based on analyses of mitochondrial and nuclear DNA sequence data

The pharaoh cuttlefish, Sepia pharaonis Ehrenberg, 1831, is a commercially fished species found from Japan to East Africa. Previous morphological and genetic work (the latter based on the 16S rRNA mitochondrial gene) suggested that S. pharaonis is a species complex, but relationships within the complex remained unresolved. To clarify these relationships, we have sequenced an additional mitochondrial gene region (cytochrome oxidase subunit I) and a nuclear gene region (rhodopsin) from over 50 specimens from throughout the range of S. pharaonis. We have also added sequence data from two specimens of Sepia ramani Neethiselvan, 2001, collected in southeastern India. Sepia ramani is a species that is morphologically very similar to S. pharaonis, and there is some question regarding its status as a distinct species. Phylogenetic analyses of a dataset comprising all three-gene regions revealed a monophyletic S. pharaonis complex consisting of a western Indian Ocean clade, a northeastern Australia clade, a Persian Gulf/Arabian Sea (‘Iranian’) clade, a western Pacific clade and a central Indian Ocean clade. Relationships among these clades remain somewhat poorly supported except for a clade comprising the Iranian clade, the western Pacific clade and the central Indian Ocean clade. One S. pharaonis specimen was collected in the Arabian Sea, but was found to be a member of the western Indian Ocean clade, suggesting that gene flow between these regions has either occurred recently or is ongoing. Both specimens of S. ramani are members of the S. pharaonis complex, but their mtDNA haplotypes are not closely related – one is a member of the central Indian Ocean clade, while the other is rather distantly related to the northeastern Australia clade. We suggest that ‘S. pharaonis’ may consist of several species, but morphological work is needed to clarify species-level taxonomy within this complex

Phylogeography of the pharaoh cuttle Sepia pharaonis based on partial mitochondrial 16S sequence data

The pharaoh cuttle Sepia pharaonis Ehrenberg, 1831 (Mollusca: Cephalopoda: Sepiida) is a broadly distributed species of substantial fisheries importance found from east Africa to southern Japan. Little is known about S. pharaonis phylogeography, but evidence from morphology and reproductive biology suggests that Sepia pharaonis is actually a complex of at least three species. To evaluate this possibility, we collected tissue samples from Sepia pharaonis from throughout its range. Phylogenetic analyses of partial mitochondrial 16S sequences from these samples reveal five distinct clades: a Gulf of Aden/Red Sea clade, a northern Australia clade, a Persian Gulf/Arabian Sea clade, a western Pacific clade (Gulf of Thailand and Taiwan) and an India/Andaman Sea clade. Phylogenetic analyses including several Sepia species show that S. pharaonis sensu lato may not be monophyletic. We suggest that ‘‘S. pharaonis’’ may consist of up to five species, but additional data will be required to fully clarify relationships within the S. pharaonis complex

Phylogeography of the Pharaoh Cuttle \u3ci\u3eSepia pharaonis\u3c/i\u3e Based on Partial Mitochondrial 16S Sequence Data

The pharaoh cuttle Sepia pharaonis Ehrenberg, 1831 (Mollusca: Cephalopoda: Sepiida) is a broadly distributed species of substantial fisheries importance found from east Africa to southern Japan. Little is known about S. pharaonis phylogeography, but evidence from morphology and reproductive biology suggests that Sepia pharaonis is actually a complex of at least three species. To evaluate this possibility, we collected tissue samples from Sepia pharaonis from throughout its range. Phylogenetic analyses of partial mitochondrial 16S sequences from these samples reveal five distinct clades: a Gulf of Aden/Red Sea clade, a northern Australia clade, a Persian Gulf/Arabian Sea clade, a western Pacific clade (Gulf of Thailand and Taiwan) and an India/Andaman Sea clade. Phylogenetic analyses including several Sepia species show that S. pharaonis sensu lato may not be monophyletic. We suggest that “S. pharaonis” may consist of up to five species, but additional data will be required to fully clarify relationships within the S. pharaonis complex

A survey on diversity and distribution of juvenile squids in the inner and western Gulf of Thailand

Juvenile squids of Loligo chinensis, 10-55mm ML and L. duvauceli, 10-65mm ML, are randomly distributed in the inner and western Gulf of Thailand at depth of 10-50m, much abundandly deeper than 20m in depth, in offshore of Chonburi Province (Sichang Island, Khram Island, Phai Island and south of Chuang Island) and from Hua-Hin of Prachuab Khirikhan Province to Langsuan of Chumphon Province. Besides, juvenile to adult of other 3 species of small-sized squids were found. Loligo n.sp., 15-50mm ML was first found in the Gulf of Thailand, at depth of 24-50m, in offshore of Pratiew (Prachuab Khirikhan Province) to Langsuan (Chumphon Province). Loliolus sumatrensis, 5-55mm ML, occured at 10-50m depth, abudantly in the inner and western Gulf of Thailand. loliolus affinis, 10-47mm ML, occured in shallower than 20m depth of the inner Gulf of Thailand

Not Available

Not AvailableThe pharaoh cuttlefish, Sepia pharaonis Ehrenberg, 1831, is a commercially fished species found from Japan to East Africa. Previous morphological and genetic work (the latter based on the 16S rRNA mitochondrial gene) suggested that S. pharaonis is a species complex, but relationships within the complex remained unresolved. To clarify these relationships, we have sequenced an additional mitochondrial gene region (cytochrome oxidase subunit I) and a nuclear gene region (rhodopsin) from over 50 specimens from throughout the range of S. pharaonis. We have also added sequence data from two specimens of Sepia ramani Neethiselvan, 2001, collected in southeastern India. Sepia ramani is a species that is morphologically very similar to S. pharaonis, and there is some question regarding its status as a distinct species. Phylogenetic analyses of a dataset comprising all three-gene regions revealed a monophyletic S. pharaonis complex consisting of a western Indian Ocean clade, a northeastern Australia clade, a Persian Gulf/Arabian Sea (‘Iranian’) clade, a western Pacific clade and a central Indian Ocean clade. Relationships among these clades remain somewhat poorly supported except for a clade comprising the Iranian clade, the western Pacific clade and the central Indian Ocean clade. One S. pharaonis specimen was collected in the Arabian Sea, but was found to be a member of the western Indian Ocean clade, suggesting that gene flow between these regions has either occurred recently or is ongoing. Both specimens of S. ramani are members of the S. pharaonis complex, but their mtDNA haplotypes are not closely related – one is a member of the central Indian Ocean clade, while the other is rather distantly related to the northeastern Australia clade. We suggest that ‘S. pharaonis’ may consist of several species, but morphological work is needed to clarify species-level taxonomy within this complex.Not Availabl

Not Available

Not AvailableThe pharaoh cuttle Sepia pharaonis Ehrenberg, 1831 (Mollusca: Cephalopoda: Sepiida) is a broadly distributed species of substantial fisheries importance found from east Africa to southern Japan. Little is known about S. pharaonis phylogeography, but evidence from morphology and reproductive biology suggests that Sepia pharaonis is actually a complex of at least three species. To evaluate this possibility, we collected tissue samples from Sepia pharaonis from throughout its range. Phylogenetic analyses of partial mitochondrial 16S sequences from these samples reveal five distinct clades: a Gulf of Aden/Red Sea clade, a northern Australia clade, a Persian Gulf/Arabian Sea clade, a western Pacific clade (Gulf of Thailand and Taiwan) and an India/Andaman Sea clade. Phylogenetic analyses including several Sepia species show that S. pharaonis sensu lato may not be monophyletic. We suggest that ‘‘S. pharaonis’’ may consist of up to five species, but additional data will be required to fully clarify relationships within the S. pharaonis complex.Not Availabl