Article

Low Genetic Variation Suggest Single Stock of Kawakawa Euthynnus affinis (Cantor, 1849) along the Indian Coast

Turkish Journal of Fisheries and Aquatic Sciences (Impact Factor: 0.38). 09/2012; 12(3). DOI: 10.4194/1303-2712-v12_3_02

ABSTRACT

Kawakawa Euthynnus affinis is an epipelagic migratory tuna species, widely distributed in the tropical and subtropical waters of the Indo-Pacific region. It constitutes the largest tuna fishery in Indian waters. In present study, restriction fragment length polymorphism (RFLP) analysis of the mitochondrial D-loop region was employed to examine the levels of genetic diversity among kawakawa samples collected from eight main fishing zones (Veraval (YE), Ratnagiri (RA), Kochi (KO), Kavaratti (ICA), Port-Blair (PB), Tuticorin (TU), Pondicherry (PO) and Vizag (VI)) along the Indian coast. A 500 bp segment of mitochondrial D-loop region was screened in 400 samples using six restriction enzymes (Rsa I, Alu I, Hinf I, Hha I, Msp I and Hae III), resulting in 13 composite morphs. Analysis of molecular variance (AMOVA) of mtDNA data revealed no significant genetic differentiation among sites (F-ST = 0.00446, P = 0.84946). Results of the genetic analyses of present study suggest the single stock of kawakawa along the Indian coast.

Download full-text

Full-text

Available from: Swaraj Priyaranjan Kunal, Dec 13, 2013
  • Source
    • "). But, in the case of oil sardine, the migratory behavior of the species gives more chance for intermixing of stocks and therefore no reproductive isolation or separation of spawning grounds was observed which are important factors regarding stock separation (Hedgecock et al. 1989; DFO 2004; Demer et al. 2012., Izzo et al. 2012 and Kumar et al. 2012). "
    [Show abstract] [Hide abstract]
    ABSTRACT: A total of 200 specimens of oil sardine Sardinella longiceps collected from Kochi in the southwest coast and Chennai in the southeast coast were subjected to truss analysis. A truss network was constructed by interconnecting 10 landmarks to form a total of 21 truss distance variables extracted from the landmarks. The transformed truss measurements were subjected to factor analysis which revealed that there is no separation of the stocks along southeast and southwest coasts. The marginal differences in shape and form are attributed to the ecological differences in the habitats which are evident from differences in length weight relationships and feeding intensity of the population along these two coasts.
    Full-text · Article · Mar 2015
    • "Pelagic marine fishes are known to exhibit little genetic divergence over large spatial scales because of their high dispersal potential at egg and larval stages, high mobility and seasonal migration of adults, and large effective population sizes (Borsa, 2003; Ely et al., 2005; Theisen et al., 2008). Little to no apparent phylogeographic structure were previously identified in some pelagic fishes, e.g., Atlantic and Pacific samples of Thunnus albacares and Katsuwonus pelamis (Ely et al., 2005) and Euthynnus affinis sampled in Southeast Asia (Santos et al., 2010) and the Indian coast (Kumar et al., 2012a). A number of studies, however, provide some evidence of genetic subdivision among demes of pelagic fishes in the Coral Triangle and the Indo-Pacific region (Perrin and Borsa, 2001; Rohfritsch and Borsa, 2005; Sulaiman and Ovenden, 2009; Lu et al., 2006; Thomas et al., 2014). "
    [Show abstract] [Hide abstract]
    ABSTRACT: Aside from having an important ecological role in the ocean food web, small pelagic fishes have become the major food source in the Sulu-Celebes Sea (SCS) which is bordered by Indonesia, Malaysia and the Philippines. Conservation and management of these fishes are of prime importance because the people living around the SCS are highly dependent on these resources. Nevertheless, basic biological information, especially relating to genetic diversity, population genetic structure, and demographic patterns, are often deficient. In this study, population genetic methods were used to investigate the genetic structure and diversity as well as historical demography of four ecologically and economically important small pelagic fishes in the SCS: Auxis thazard (Lacepède, 1800); Bali sardine, Sardinella lemuru (Bleeker, 1853); Indian mackerel, Rastrelliger kanagurta (Cuvier, 1816); and bigeye scad, Selar crumenophthalmus (Bloch, 1793). Fish samples were collected from 5 geographic locations: (Philippines: Zamboanga, Tawi-Tawi and Palawan; Indonesia: Manado; and Malaysia: Kudat) around the SCS and muscle tissues were sequenced for the mitochondrial DNA (D-loop) control region (n = 150, 231, 169 and 224 for AT, SL, RK, and SC, respectively). Low overall FST values, high haplotype diversity but low genetic differentiation among haplotypes, and highly mixed clusters from BAPS analysis indicate no distinct genetic population structuring among the samples. Furthermore, neutrality tests, mismatch analysis and Bayesian skyline plots suggest population expansion for all species. Generally, these results indicate that the four marine pelagic species are very resilient over evolutionary time scales; yet, proper management is very necessary, especially because overexploitation of small pelagic fishes has already been reported in the SCS region.
    No preview · Article · Feb 2015 · Fisheries Research
  • Source
    • "The identification of distinct populations or stocks which are geographically or temporarily isolated from one another forms one of the important aspects regarding fisheries management (Booke, 1981). But, in the case of Indian mackerel, the migratory behaviour of the species gives more chance for intermixing of stocks and therefore no reproductive isolation or separation of spawning grounds is observed which are important factors regarding stock separation (Hoolihan et al., 2006; Buckworth et al., 2007; Shepard et al., 2010; Sajina et al., 2011; Kumar et al., 2012) "
    [Show abstract] [Hide abstract]
    ABSTRACT: A total of 200 specimens of Indian mackerel (Rastrelliger kanagurta) were collected from Kochi in the south-west coast and Chennai in the south-east coast and they were subjected to truss analysis. A truss network was constructed by interconnecting 10 landmarks to form a total of 21 truss distance variables extracted from the landmarks. The transformed truss measurements were subjected to factor analysis which revealed that there is no separation of the stocks along south-east and south-west coasts. Thus the present study has indicated that the population of Indian mackerel from south-east and south-west coasts remains the same.
    Full-text · Article · Sep 2014 · Indian Journal of Fisheries
Show more