LENGTH-WEIGHT RELATIONSHIP AND CONDITION FACTOR OF SOME COMMERCIAL FISH SPECIES IN LEKKI LAGOON, SOUTHWEST NIGERIA.
Keywords:Length-weight relationship, Lekki lagoon, condition factor, fish stock assessment.
A study on Length-Weight Relationship (LWR) and condition factor was carried out on 3 commercial fish species: Chrysichthys nigrodigitatus, Coptodon zillii and Ethmalosa fimbriata species in the Lekki Lagoon, Nigeria. Samples were collected between January and July 2022. A total of I, 386 fish were randomly collected from commercial fishermen selected in both dry and wet seasons from all landing sites around Lekki Lagoon. The total length and total weight of fish samples were measured using standard methods to the nearest 0.01 cm and 0.01 g. The average mean length ranged from 11.07±0.90 cm to 20.15±7.23 cm, and the average mean weight ranged from 13.51±3.17g to 205.97±146.48 g. Average length and weight were lower in the wet season than in the dry season. The ‘b’ value of C. nigrodigitatus showed a negative allometric growth pattern, and the total length was positively correlated with the total weight of the fish (r²=0.98 and 0.93) in both seasons. The ‘b’ value in C. zillii were 2.94 and 3.00 for both dry and wet seasons. LWR was positively correlated (r²=0.9861 and 0.9905) while the growth pattern was isometric. The value of ‘b’ for E. fimbriata during the study for both dry and wet seasons were 2.33 and 2.56 and r²=0.745 and 0.77 respectively. Respective condition factors ‘k’, dry and wet seasons, were: 0.97g/cm³ and 0.83g/cm³ for C. nigrodigitatus, 2.19g/cm³ and 1.87g/cm³ for C. zillii and 0.95g/cm³ and 0.99g/cm³ for E. fimbriata. The study showed that the condition factor was highest in C. zillii in both seasons in the water body. Therefore, efforts should be directed towards the sustainable management of the fisheries.