Length-weight Relationships and Condition Factors of Three Commercially Important Fish Species from Roseires Reservoir, Blue Nile, Sudan

Abstract

This study aimed to investigating the length-weight relationships and condition factors of three commercially important fish species in Roseires Reservoir on the Blue Nile, Sudan. A total number of 387 specimens of Labeo senegalensis, 285 of Alestes dentex, and 318 Oreochromis niloticus) were collected from four sampling sites on the Roseires Reservoir, using gillnets with varying mesh sizes (4, 8, 10, and 12 cm) from November 2015 to October 2016; The total and standard lengths of each fish were measured to the nearest 1.0 mm, using measuring board; the body weight was recorded to the nearest 1.0 gm, using a digital weighing balance, version FRUIT 2000B. The results showed that the three species exhibited negative allometric growth (b < 3) in all sites, except Labeo senegalensis in Wad El Mahi site which showed positive allometric growth (b’ value 3.182), and moderate to high correlation coefficient (r = 0.442 - 0.998) The condition factor displayed average values ranged from 1.963- 3.751 (Labeo senegalensis) to 2.080 - 3.287 (Alestes dentex) and 2.336 - 3.287 (Oreochromis niloticus), indicating good health conditions and wellbeing of the three species investigated in the study area. The results of this investigation provide baseline data and valuable information on the growth pattern and health status of three fish species in the Roseires reservoir and can used as a basis for effective management measures of the three fish species in the Reservoir.