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Auteur (up) Tessier, A.; Blin, C.; Cottet, M.; Kue, K.; Panfili, J.; Chanudet, V.; Descloux, S.; Guillard, J. doi  openurl
  Titre Life history traits of the exploited Nile Tilapia (Oreochromis niloticus – Cichlidae) in a subtropical reservoir (Lao PDR) Type Article scientifique
  Année 2019 Publication Revue Abrégée Cybium  
  Volume 43 Numéro 1 Pages 71-82  
  Mots-Clés age-determination; community; fish; Fisheries; growth; l.; Man-made Lake; man-made lakes; nam theun 2; Otolith; perciformes; phytoplankton; population; South-East Asia  
  Résumé Biological traits of Oreochromis niloticus were studied in order to identify potential differences between the population of the Nam Theun 2 Reservoir and other populations in Asia and in Africa. The study also aimed to characterize the demographic structure of the exploited population by fisheries in the reservoir. Toluidine-stained transverse section of otoliths from 322 specimens, collected between November 2015 and January 2017, were analysed to identify the periodicity of annulus formation and to age individuals. Length, weight, sex and sexual maturity stage were recorded. Life history traits were characterized by length-weight and length age relationships. The periodicity of annulus formation was annual, with complete formation of the translucent zone at the beginning of the warm and wet season (June and July). The length-age key has been established and was composed of 9 age classes, ranging from 0 to 8 years old. Males showed positive allometric growth whereas juveniles and females exhibited isometric growth. The study showed an asymptotic standard length of 658 mm and a low growth rate (K = 0.08 year(-1)). The sex ratio was equilibrated, and first maturity of females was at 277 mm standard length. The population was composed of individuals aged 3 years old and older, and 60% of the landings were composed of individuals aged 5 years and older. The growth rate was lower than for Asian and African populations, and the age-length key provided was specific to the studied reservoir. However, some biological traits of the O. niloticus population were similar to those found for other population in the world: (i) formation of an annual annulus during the reproduction period, at the beginning of the warm and wet season like populations from subtropical countries, and (ii) an isometric or a positive allometric growth as seen in populations that were not overexploited and were living in favourable environmental conditions. Therefore, the present study suggests that the O. niloticus population of the NT2 Reservoir was not overexploited at the time of the survey.  
  Auteur institutionnel Thèse  
  Editeur Lieu de Publication Éditeur  
  Langue English Langue du Résumé Titre Original  
  Éditeur de collection Titre de collection Titre de collection Abrégé  
  Volume de collection Numéro de collection Edition  
  ISSN 0399-0974 ISBN Médium  
  Région Expédition Conférence  
  Notes Approuvé pas de  
  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2553  
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