Volume 43, No. 02, Month MAY, Year 2019, Pages 43 - 56

Reproductive biology, trophodynamics and stock structure of ribbonfish (trichiurus lepturus linnaeus, 1758) in tropical marine waters of the bight of benin

Oluwaseun Christianah Ojelade, Isaac Tunde Omoniyi, Waidi Oyebanjo Abdul, Festus Idowu Adeosun, Adekunle Adedoyin Idowu, Ikililu Abdulraheem

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This study was an attempt to understand the exploitation rate and mortality parameters of Trichiurus lepturus Linnaeus, 1758 for sustainable exploitation and conservation of this important fish species in Ogun coastal waters, Nigeria. Reproductive biology, trophodynamics and stock structure of the population was assessed from ribbonfish captured with graded gillnets (18, 22, 26, 30, 40, 45, 50, 65, 70, 75, 80 and 90 mm, knot-to-knot). A total of 1,616 individuals of T. lepturus were captured and subjected to descriptive and inferential statistical tools. Sex ratio of males: females (0.4:1) was significantly (x2=32.144; p=0.0007) different from unity. Peak spawning seasons were December and July. Total fecundity ranged between 7,051 and 12,456 eggsyr-1. In stomach contents, juveniles of ribbonfish dominated the finfish group with an index of relative importance (IRI) value of 42.6%, while Penaeids occurred most in the shellfish group with IRI value of 17.3%. Feeding intensity showed that juveniles fed mostly on prawns and crustaceans while adults fed more on finfishes. T. lepturus exhibited positive allometric growth with modal classes of 35-36.9 and 45-46.9 cm; von Bertallanfy model gave an asymptotic-length (L∞) of 69.3 cm. Exploitation rate of T. lepturus is 0.73, which indicates that the stock of T. lepturus is marginally over-exploited.


Fecundity, Feeding-intensity, Fish eggs, Stock-structure


Published by : Faculty of Fisheries, Kasetsart University
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