Length-weight relationship and condition factor of Clarias gariepinus and Tilapia zillii in Lake Alau and Monguno hatchery, Borno State, Nigeria

Length-Weight relationship and condition factor of Clarias gariepinus and Tilapia Zillii were studiedin lake Alau and Monguno hatchery, both in Borno State of Nigeria, for a period of two weeks. A total of 98 C. gariepinus and 140. T. zillii were measured. The length-weight regression coefficient (b) for both fishes in lake Alau were not significantly different from the hypothesized value 3, but for both fishes in Monguno hatchery (b) differed signifcantly from the hypotheszed value. Isometric growth of both fshes was recorded in lake Alau while a comparative decline in weight in relation to specific length of fishes was recordedin Monguno hatchery. Furthermore, condition of C.gareipinus in lake Alau revealed that all size groups of the fsh grew better than those in Monguno hatchery, while the condiion of T. zillii in Monguno hatchery was better than that in lake Alau. Although our results suggest that C. gariepinus in lake Alau grew faster than that cultured in Monguno hatchery, the study is not conclusive as abiotic, biotic, and sampling error might have interplayed. The reverse is also true for the growthpotentials of T. zillii in Monguno hatchery whencompared to that in lake Aau.