Length –weight relationship and condition factor of long neck croaker –Pseudotolithus typus (Bleeker, 1863) from Lagos Lagoon, Nigeria

Abstract

The length-weight relationship and condition factor of Pseudotolithus typus from makoko lagoon, Lagos state was evaluated over a period of 24 weeks in September 2018 to February, 2019 from fishermen catches at Makoko landing point. A total of 93 specimens were collected and transported in ice-packed container to the wet laboratory of the Department of Biological Oceanography, Nigerian Institute for Oceanography and Marine Research (NIOMR) for further examination. These specimens were usually collected during early hour of the morning. The sampling methods were season stratified.Total length and Standard lengths of each fish sample were measured to the nearest 0.50cm using a measuring board. Specimens were weighed with Camry model EK5350 of 5kg capacity to the nearest 0.10 g after blotting dry with filter paper. The total weight ranged from 129.00cm-261.00cm with a mean value of 200.01cm.The degree of association between the total length and weight was computed from linear regression analysis. The overall exponential equations for the length weight relationship are; LogW = -2.37 + 2.208logL. The highest correlation coefficient value recorded in December with a value of 0.87. Condition factors were significantly for both wet and dry season (P>0.05). Pseudotolithus typus in this study exhibited a negative allometric growth (b < 3) with a mean b value of 2.21.The It has been established that when K value is greater than one, this indicates that the fish species is living well in the concerned habitat (Ikongbeh et al., 2012); the ‘K’ value in this experiment, which has varied values suggests that the wellbeing of Pseudotolithus typus varies with season.