LENGTH-WEIGHT RELATIONSHIPS AND CONDITION FACTORS OF SIX FISH SPECIES IN ATBARA RIVER AND KHASHM EL- GIRBA RESERVOIR, SUDAN

This study describes the length-weight relationships (LWR) and condition factors of six fish species from sixfamilies of ecological and economic importance, found in Atbara River and Khashm el- Girba reservoir. A total of 1118specimens were caught by using various mesh size of gill nets from January, 2007 to December, 2007. The growthcoefficient (b) values obtained for the six fish species ranged between 2.278 for Clarias lazera and 3.680 for Bagrusbayad and differed significantly (p<0.005) from 3, which indicates that most of the fish species (61.1%) have negativeallometric growth. The condition factors (K) of the fish species ranged from (0.506±0.416) in Clarias lazera to(3.415±0.707) in Oreochromis niloticus and about 83.3% of these condition factors fall outside the range recommendedas suitable for matured fresh water fish species in the tropics