Seasonal variation in the length-weight relationships and condition factor of Synodontis schall (Bloch and Schneider, 1801) (Siluriformes: Mochokidae) in man-made Lake Ayamé 2 (Côte d’Ivoire)

Abstract

Length-weight relationship (LWR) and condition factor (K) of Synodontis schall (Bloch and Schneider, 1801) were studied in man-made Lake Ayame 2. Samples of S. schall were collected from catches of artisanal fisheries using various mesh size of gill nets from May 2015 to April 2016. Length-weight data were analyzed and length-weight relationship graphs were plotted for the dry and rainy seasons of the sampling years. The b values in the LWR (W= aLb) varied between 2.5163-2.7857 for the dry seasons and 3.0008-3.001 for the rainy season indicating that the growth pattern of S. schall had negative allometric and isometric in the seasons respectively. The average condition factor (K) were less than 1 (Mean: 0.315-0.647) during the dry season revealing that this fish species was not in good physiological sate of well-being. However, it was in better condition (K-values were greater than 1; Mean: 1.0375-1.357) during the rainy season.