Browsing by Author "Moreau, J."
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Item Population dynamic of Arastromateus Niger in Kuwaiti waters as assessed using length-frequency analysis(Journal of Applied Ichthyology (23): 592-597, 2007) Dadzie, S.; Abou-Seedo, F.; Moreau, J.The population dynamics of the black pomfret, Parastromateus niger, sampled from commercial gill-net catches from Kuwaiti waters of the Arabian Gulf, were investigated from October, 2003 to September, 2005. Length-based stock assessment using the FISAT software package showed an asymptotic length of 65 cm TL and growth curvature of 0.34 year-1. Raw data as well as that corrected for probability of capture indicated a recruitment from February to September. The total mortality coefficient was estimated to be 1.20, a natural mortality of 0.58 and fishing mortality of 0.52. The selectivity model based on the running average showed that 25% of 14.0 cm TL fish, 50% of specimens reaching 15.3 cm TL, and 75% of all specimens of 20.2 cm. TL encountering the gear were retained. Relative yield-per-recruit analyses revealed a current exploitation rate of 0.43%; this is below the maximum sustainable yield index, indicating for sustainable fishery of P. niger that the exploitation rate could be increased 0.6, provided size of fish at the first capture, i.e., the legal size, is also increased to 32.5 cm TL. These results suggest that P. niger stocks in Kuwaiti waters, contrary to existing views, are moderately exploited. These conclusions, however, is critically dependent on the estimate of natural morality, which requires further confirmation.Item Reproductive guilds (maturation, spawning frequency and fecundity pomfret, parastromateus niger (Caranguidae) in the Kuwaiti water Gulf(Journal of Applied Ichthyology (24): 562-568, 2008) Dadzie, S.; Abou-Seedo, F.; Moreau, J.Oogenesis, oocyte maturation pattern, spawning rhythm, spawning frequency, batch fecundity and oocyte diameter-frequency distribution of the black pomfret, Parastromateus niger (Block, 1795) in Kuwaiti waters were investigated from October, 2003 to September, 2005, using histological and morphological methods. The process of development is divided into four major phases: (i) primary growth phase; (ii) secondary growth; (iii) maturation phase; and (iv) spawning phase, followed by the regressed phase. Development of the yolky oocyte maturation, in dear differentiation between a ready batch of oocytes (ready for spawning ) and a reserve pool. Consequently, P. niger is capable of spawning multiple times throughout the reproductive season. Spawning frequency estimates, based on final oocyte maturation (FOM) method indicated that the species spawns once every 2.8 days during an 8-month spawning season lasting from February to September, with a potential annual number of 22.4 spawns. Batch fecundity (BF) (2132-2001 648, mean 406 010 eggs), was significantly positively related to both standard length (SL) P < 0.05) and ovary-free body weight (OFBW) (P < .0.05), both parameters being good predictors of BF (r2 = 30.8% for SL, from 22 cm onwards, and r2 = 29.6% for OFBW, from 129.5 g onwards). No significant differences in monthly BF were found throughout the spawning season. Relative batch fecundity was 336 eggs/g OFBW; thus, estimate for potential annual relative batch fecundity was 7525 eggs g-1 OFBW. The oocyte diameter-frequency distribution analysis revealed a multimodal distribution (at 100-200, 300-400 and 500-700 µm), confirming the evidence of multiple spawning.