Length-weight relationship and relative condition factor of Gorean snapper, Lutjanus goreensis (Valenciennes, 1830) in the coastal zone of Lagos, south-west Nigeria

Abstract

Snappers are highly recommended as choice seafood and as viable candidate for cage culture in the brackish water and marine environments. However, very limited data exists on biological parameters of the snappers, Lutjanus species throughout their distribution range. Hence, the present study sought to improve knowledge on Length-Weight Relationship (LWR) and relative condition factor (Kn) of the Gorean snapper, Lutjanus goreensis (Valenciennes, 1830) sampled between December 2008 and December 2009 in the coastal zone of Lagos, Nigeria. Specimens were collected from landings of artisanal fisheries and inshore trawl fisheries. A total of 822 unsexed estuarine (7.90 to 34.90 cm and 9.51-695.60 g) and 377 sexed marine (21.90 to 56.10 cm and 156-2 975 g) specimens were analyzed. The overall value of the slope, b for the LWR indicated negative allometric growth for unsexed estuarine (2.860); marine male (2.856) and female (2.917) specimens, respectively. The relative condition factor, Kn did not vary significantly from 1. Sex-wise variations of b values and Kn were not significant either. The present study presents, for the first time, baseline information on the length-weight relationship parameters and condition of L. goreensis in the marine waters of Nigeria and in the Eastern Atlantic Ocean. The results are useful indicators to assess the well-being of wild Gorean snapper populations in Lagos coastal zones for management and under culture conditions.

Keywords: Lutjanus goreensis; length-weight relationships; condition factor; Lagos; Nigeria