Weight-length relationship and condition factor of Sarotherodon melanotheron (Rüppell, 1852) in the special wildlife reserve of Gueumbeul (RSFG) in Senegal

Abstract

The Special Wildlife Reserve of Gueumbeul (RSFG) consists of a water reservoir (the basin) frequented by a diversity of fish and migratory birds. The most represented in terms of abundance is the species Sarotherodon melanotheron. The objective of this study was to determine the relations weight-length and to characterize the condition factor of S. melanotheron, in the basin of Gueumbeul. A total of 628 fish were sampled including 364 males, 178 females and 86 immature individuals from March 2019 to February 2020. The total length (TL) of S. melanotheron specimens sampled in the Gueumbeul reserve ranged from 6.1 cm to 17.6 cm with an average of 11.08 ± 1.82 cm and the weight (W) from 4.8 g to 103 g with an average of 27.25 ± 12.09 g. The results of the weight-length analyses gave values of 2.69 and 2.77 for the regression coefficient (b) for males and females respectively, and 2.72 and 2.76 for the dry and wet seasons. This reflects negative allometric growth in both sexes (male and female) and by season (dry and wet season). No statistically significant difference was noted for dry and wet season b values for S. melanotheron in the Gueumbeul basin, unlike condition factors between males and females and between dry and wet season where significant differences in K values were noted.