Length-Weight Relationship, Length Frequency Distribution and Condition Factor of the Shiny Nose Polydactylus quadrafilis (Cuvier, 1829) From the Cross River Estuary, Nigeria

Abstract

This study was carried out to evaluate the length-weight relationship, length frequency distribution and condition factor of the Shiny Nose Polydactylus quadrafilis from the Cross River estuary, Nigeria. A total of 350 freshly caught specimens of P. quadrafilis were collected between April 2012 and March 2013 from the catches of the artisanal fisheries from major landing points of the estuary. Results obtained showed a negative allometric growth pattern for this fish species with a significant linear relationship given by the equation: TW= 0.1325TL2.1884 and Log TW = 2.1884LogTL – 0.8777 (r = 0.8610, r2 = 0.7413t, n = 350, P< 0.05, df = 348). The length frequency distribution of P. quadrafilis showed a unimodal class size distribution with the highest length frequency in 20.1cm -25 cm length class (291), followed by 25.1 cm -30.0 cm (32) and lowest (27) in 15.1cm – 20.0 cm respectively. Fulton‟s condition factor (K) ranged between 0.579 to 1.650 with a mean 1.075 ± 0.15, indicating that P. quadrafilis were in good physiological health condition. In conclusion, the baseline data on length-weight relationship, condition factor and length-frequency distribution of P. quadrafilis from the Cross River estuary provided in this study is crucial in the sustainable management of this species in the estuary. Also, these findings will be useful in evaluating the population dynamics, stock and the aquaculture potential of P. quadrafilis for future purpose.