Study of some biological aspects of the Nile Carp, Labeo niloticus (Pisces, Cyprinidae) from Khashm El-Girba Reservoir and Atbara River; Eastern Sudan: II, length-weight relationship, condition factor and age structure

Abstract

This study was undertaken to assess the length-weight relationship, condition factor and age structure, of the Nile carp, Labeo niloticus, in Khashm El-Girba reservoir and Atbara River, Sudan, from December 2015 to November 2016. Samples of fish were collected bi-monthly from three locations, namely; Um Aswad (Atbara River), El-Remila and El-Monaba (Khashm El-Girba reservoir), using beach seine nets of 1.2, 4.0 and 7.0 cm stretched mesh. Out of a total number of 1,190 specimens of L. niloticus collected from the three sampling sites, 189 specimens were randomly selected to determine age. The relationship between length and weight indicated negative allometric growth pattern in all three locations, where the slope (b) of the (LWR) was highly significant (p<0.001) and ranged from 2.178 to 2.885. The mean condition factor (K) varied monthly in the three locations with values ranging from 1.671 in Um Aswad (Atbara River) to 2.548 in El-Monaba (reservoir). Although the age of L. niloticus ranged from 0+ and 3+ years, yet, most of the studied fish are between age 0 + and 1+.