Length-weight relationship and condition factor of Mochokidae Inase River, Niger Delta, Nigeria

Abstract

This study was carried out on five species of the family Mochokidae; Synodontis nigrita, S. schall, S. respinatus, S. membranaceous and S. ocellifer from Aseriver, Niger Delta Nigeria, to provide information on their length-weight relationship (LWR) and condition factor (K). A total of 245 samples of all the species were examined between June and September 2015. The highest abundance was recorded in S. nigrita (74 specimens; 30.20%), S. membranaceous was the least (24 specimens; 9.80%). Length-weight relationships showed that all the fishes exhibited positive allometric growth pattern with regression exponent b value greater than 3, while the correlation coefficient (r) obtained ranged from 0.733 to 0.885 revealed a positive correlation. The results also showed that the condition factor (K) of all the species were greater than one (1) implying that all the fishes were in good physiological state of well-being in the river. The study however recommended other complementary studies on other aspects of the biology of these species to provide the needed ecological information for the effective exploitation and conservation of the species in the river.

Keywords: Ase River, length-weight, health status, Mochokids, Niger Delta