Tilapia galilaea size7/5/2023 Analyses revealed difference between fast growing domesticated fish rose for aquaculture with higher to the tilapia growing in natural and challenging environments. Despite this issue, the Growth Performances Indices ( ) gathered into the literature can serve as baseline and confirmed the wide phenotypic plasticity of the species due to environmental factors. This example highlights the variability of the parameters calculated from different methods and thus weaken worldwide and even inter-site comparisons. To maximize the yield per recruit, increase the biomass and sustain this fishery, enlarging the gillnet mesh size of the gill-net is recommended. These results showed that the population is overfished with too many juveniles caught ( L 50 = 210.4 mm 50% mature stages at 295 mm). This estimated stock of 165 tons (more than 700 000 tilapias) was characterized by high mortality (no population growth). The exploitation rate E = 0.79 is over the E max = 0.594 obtained by relative yield and biomass per recruit. According to these landing data, the total, natural and fishing mortality were Z = 1.41 year −1, M = 0.30 year −1 and F = 1.11 year −1. The growth parameter K was estimated to be 0.23 year −1, with asymptotic length L∞ = 52.5 cm based on the length frequency distribution analysis with the fish landing data. Furthermore, experimental fishing data provided irrelevant parameters due to insufficient representativeness of the sample size. The length-at-age data analysis (using otoliths analysis, N = 258) gave slightly different results with the length frequency distribution analysis of fish landings (11 820 individuals). Population parameters of this alien fish were investigated using the FiSAT II software with the most popular methods of bioparameters assessment to check their interchangeability within a same stock and the same year 2016. The species was then suspected to be introduced in the seventies in Laos and subsequently in the Nam Theun watershed where the NT2 Reservoir was impounded in 2008. In Lao People’s Democratic Republic (PDR), like in other countries, this exotic species is well established due to its self-reproduction ( De Silva et al., 2004 CABI, 2018) facilitated by its particular life history traits and plasticity ( Ishikawa et al., 2013). The species was later promoted for aquaculture development in the early 1990s in Lao PDR ( Garaway et al., 2000). * e-mail: Nile tilapia ( Oreochromis niloticus) was introduced in Southeast Asia, such as in Thailand, in the mid-1960s for aquaculture purposes ( Pullin et al., 1997 De Silva et al., 2004). IRD, Lemar UMR 6539, IUEM Technopôle Brest-Iroise,ĮDF, Hydro Engineering Center, Savoie Technolac,ĮDF-Dismantling and Environmental Services Division, Nam Theun 2 Power Company Limited (NTPC), Environment & Social Division, Environment Department, Gnommalath Office, (INRA – USMB), Centre Alpin de Recherche sur les Réseaux Trophiques et les Ecosystèmes Limniques, Tessier 2 ,7īiogéosciences, UMR 6282 CNRS, Université Bourgogne Franche-Comté,
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