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Anderson F.E.,Southern Illinois University Carbondale | Engelke R.,Southern Illinois University Carbondale | Jarrett K.,Southern Illinois University Carbondale | Valinassab T.,Iranian Fisheries Research Organization | And 6 more authors.
Journal of Molluscan Studies | Year: 2011

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. © 2010 The Author. Published by Oxford University Press on behalf of The Malacological Society of London, all rights reserved.

Nootmorn P.,Andaman Sea Fisheries Research and Development Center | Petpiroon S.,Kasetsart University | Maeroh K.,Gulf
Kasetsart Journal - Natural Science | Year: 2010

Thai tuna longliners were operating in the Indian Ocean from 2000 to 2006; data from their logbooks displayed important information of their fishing operation. Total annual catches during the period were: 384.90, 390.93, 93.57, 252.48, 272.41, 280.12 and414.44 tonnes, with a value of 2, 1.84, 0.46, 1.16, 1.58, 0.98 and 2.42 million USD, respectively. Fishing grounds were in four zones namely: the Bay of Bengal, the west coast of Indonesia, Somalia and the Seychelles, and the southern part of the Indian Ocean. The highest catch rate was found in Somalia and the Seychelles (1.3 fish/100 hooks), followed by the west coast of Indonesia (1.2 fish/100 hooks) and the southern part of the Indian Ocean (1.0 fish/ 100 hooks). The lowest catch rate was reported in the Bay of Bengal (0.7 fish/100 hooks), which compared to other fishing grounds. The major catch species were bigeye tuna (Thunnus obesus), yellowfin tuna (T. albacares), albacore tuna (T. alalunga), and swordfish and other large pelagic species comprising 36.64, 35.77, 20.28 and 7.31% of the total seven-year catch, respectively. Bigeye tuna were caught in all fishing grounds, with the highest catch in the southern part of the Indian Ocean. Yellowfin tuna occurred in all fishing grounds. However, the highest abundance was found in Somalia and the Seychelles, while the lowest numbers were found in the Bay of Bengal. Albacore tuna were dominant in the southern part of the Indian Ocean. Other large pelagic species recorded included: swordfish (Xiphias gladius), sharks, blue marlin (Makaira mazara), black marlin (M. indica), striped marlin (Tetrapturus audax) and sailfish (Istiophorus spp). Thai tuna longliners fished north of equator during 2000 to 2002 and moved south of the equator during 2003 to 2006. Analysis of catch data by the PRIMER program showed changes in target species from yellowfin tuna, bigeye tuna, swordfish and other species during 2000 to 2002 to albacore tuna, bigeye tuna, yellowfin tuna, swordfish and other species during 2003 to 2006.

Nootmorn P.,Andaman Sea Fisheries Research and Development Center | Petpiroon S.,Kasetsart University | Maeroh K.,Gulf
Kasetsart Journal - Natural Science | Year: 2010

Six Thai industrial tuna purse sein fishing vessels operated in the Indian Ocean from 2005 to 2006. Fishery information and logistical data were gathered from log books, port sampling and interviews to create a systematic diagram of data collection and processing. The results will be used to support and implement responsible fishery operations under a resolution of the Indian Ocean Tuna Commission. The total catch reported was 12,216 metric tonne (tonne) in 2005 and 23,161 tonne in 2006, with the main fishing ground being off Somalia and the main fishing practice was with associated schools. The highest values for catch data, catch per unit effort (CPUE) and the number of sets were obtained during February to April and September to November in 2006. The monthly catch, CPUE and number of sets ranged from 383-4539 tonne, 15 to 61 tonne/set and 15 to 144 sets, respectively. Skipjack tuna was the main target fish, followed by bigeye tuna, yellowfin tuna and bonito. Skipjack tuna made up a high proportion of the catch during March to September, while bigeye and yellowfin tuna made up a high proportion from September to December 2005 and from January to February in 2006. The size range of skipjack, bigeye and yellowfin tuna varied from 39-75, 45-133 and 33-152 cm, respectively, whilst the length of 50% of capture fish was 60,66 and 81 cm, respectively. Most of the bigeye and yellowfin tuna were juvenile. The status of bigeye tuna from tuna purse seine fishing was stable in terms of catch and CPUE.

Diaz-Jaimes P.,National Autonomous University of Mexico | Uribe-Alcocer M.,National Autonomous University of Mexico | Rocha-Olivares A.,Research Center Cientifica Educacion Superior Of Ensenada | Nortmoon P.,Andaman Sea Fisheries Research and Development Center | Durand J.D.,Institute Of Recherche Pour Le Developpement
Molecular Phylogenetics and Evolution | Year: 2010

Pelagic fish that are distributed circumtropically are characterised by a low population structure level as a result of a high capacity for dispersion and large population sizes. Nevertheless, historical and contemporary processes, including past demographic and/or range expansions, secondary contact, dispersal, gene flow, and the achievement of large effective population sizes, may play a part in the detection of divergence signals, especially in the case of tropical pelagic species, whose distribution range depends strongly on the sea surface temperature. The connectivity and historical demography of Atlantic, Indian, Pacific and Mediterranean populations of dolphinfish (Coryphaena hippurus) was studied using partial sequences of the mitochondrial DNA NADH dehydrogenase subunit 1 (ND1). AMOVA analyses revealed significant inter-oceanic divergence with three phylogroups located in the Indo-Pacific, Eastern Atlantic, and Mediterranean Sea, the last one being the most divergent. However, it was not possible to clearly observe any genetic differentiation between the Indo-Pacific and Atlantic populations, as has been reported for most tropical pelagic species of tuna and billfishes. This supports the assumption of recent dispersal among basins facilitated by the actual continuous distribution of dolphinfish populations. Moreover, the lack of a divergence signal for populations separated by the Panamanian Isthmus reveals that genetic drift does not exert a strong influence on tropical pelagic species with large effective population sizes. © 2010 Elsevier Inc.

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