Some Biological Characteristics of Chrysichthys nigrodigitatus from Luubara Creek, Niger Delta, Nigeria

Abstract

The study of biological characteristic of C. nigrodigitatus caught using multiple and single long-line was carried out for twelve months. The Von –Bertallanffy growth function was used to estimate the growth characteristics. The growth coefficient (K) and growth performance index (Ø) were 0.740 and 2.37, respectively, indicating it grows fast. The instantaneous rates of total, natural, and fishing mortality were 3.23, 1.18 and 2.05 per year, respectively. The resultant exploitation ratio was 0.635, indicating that the fishery was overexploited. More so, the ratio of length at first capture (Lc) to asymptotic length (L∞). (Lc/ L∞) depicted that this species was caught at a small size which may lead to growth over-fishing. The extreme mounting fishing pressure and harvesting silver catfish when the size small require application fishing regulations that will watch over the species in creek. Management regulation, particularly seasonal closures coinciding with the period of spawning, should be implemented to avoid the eventual collapse of this fishery.