Browsing by Author "Abou-Seedo, F."
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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 aspects of the black pomfret, Parastromaleus Niger in the Kuwaiti waters of the Arabian Gulf(Asian Fisheries Science (22): 265-275, 2009) Dadzie, S.; Abou-Seedo, F.; Gomes, T.The reproductive activities of the male and female black promfret parastromateus niger in Kuwaiti waters were investigated from October, 2003 to September, 2005. Analysis of seasonal variations in the gonadosomatic index (GSI) during the two-year study period revealed high values from February to September, suggesting that the black pomfret has a prolonged spawning season, from February to September, suggesting that the black pomfret has a prolonged spawning season, from February to September. GSI fluctuations correlated positively with rising water temperatures in Kuwait from low values in both parameters in January to high values in February/March (r = 0.836, p < 0.05) for males and r = 0.764, p < 0.05 for females), suggesting that temperature plays a role in triggering spawning in both the sexes. Analysis of seasonal distribution of maturity stages for the two years revealed the presence of ripe/running males and females from February to September, thus confirming the spawning periodicity revealed through the analysis of fluctuations in the GSL. Macroscopic and microscopic studies of maturity stages revealed six stages in the males and seven in the females. The logistic function based on pooled data for the two years revealed that the minimum size at sexual maturity (L50) was attained at a size of 30.9 cm SL in males (r2 = 0.284) and 36.5 cam SL in females (r2 = 9.355). The ratio of males to females in monthly samples did not depart significantly from the hypothetical 1:1 during the entire study period (÷ 2 = 61.9, d.f. = 11, p < 0.05). Total fecundity ranged from 71 305 in a fish measuring 39.8 cm SL and weighing 1 572.5 g to 3.895 in a 49 cm SL and 3 630 g fish, with a mean of 1 216.734 eggs. Positive correlations were found between fecundity and ovary-free body weight standard length and ovary weight, and a negative one with egg size. The average relative fecundity was 948 eggs/g ovary-free body weights, which was neither a function of fish standard length nor ovary-free body weight.Item Reproductive aspects of the black pomfret, parastromaleus niger in the Kuwaiti waters of the Arabian Gulf(Asian Fisheries Science (22): 265-275, 2010) Dadzie, S.; Abou-Seedo, F.; Gomes, T.The reproductive activities of the male and female black promfret parastromateus Niger in Kuwaiti waters were investigated from October, 2003 to September, 2005. Analysis of seasonal variations in the gonadosomatic index (GSI) during the two-year study period revealed high values from February to September, suggesting that the black pomfret has a prolonged spawning season, from February to September, suggesting that the black pomfret has a prolonged spawning season, from February to September. GSI fluctuations correlated positively with rising water temperatures in Kuwait from low values in both parameters in January to high values in February/March (r = 0.836, p < 0.05) for males and r = 0.764, p < 0.05 for females), suggesting that temperature plays a role in triggering spawning in both the sexes. Analysis of seasonal distribution of maturity stages for the two years revealed the presence of ripe/running males and females from February to September, thus confirming the spawning periodicity revealed through the analysis of fluctuations in the GSL. Macroscopic and microscopic studies of maturity stages revealed six stages in the males and seven in the females. The logistic function based on pooled data for the two years revealed that the minimum size at sexual maturity (L50) was attained at a size of 30.9 cm SL in males (r2 = 0.284) and 36.5 cam SL in females (r2 = 9.355). The ratio of males to females in monthly samples did not depart significantly from the hypothetical 1:1 during the entire study period (÷ 2 = 61.9, d.f. = 11, p < 0.05). Total fecundity ranged from 71 305 in a fish measuring 39.8 cm SL and weighing 1 572.5 g to 3.895 in a 49 cm SL and 3 630 g fish, with a mean of 1 216.734 eggs. Positive correlations were found between fecundity and ovary-free body weight standard length and ovary weight, and a negative one with egg size. The average relative fecundity was 948 eggs/g ovary-free body weights, which was neither a function of fish standard length nor ovary-free body weight.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.