Impact of seasonal variation on the growth dynamics of the marine catfish, Arius maculatus (Siluriformes: Ariidae) collected from Karachi fish harbour

Abstract

Overfishing is the main cause of fish stock exploitation in the marine environment. In the current study growth dynamics of the marine catfish, Arius maculatus collected from Karachi Fish Harbour were studied. The relationship between total length and weight (W=aLb) was significantly linear (p<0.001). The condition factor (Kf) varied from 1.06±0.12 to 1.23±0.07. The ‘b’ values and R2 values indicated that the growth was significantly (p<0.001) positive allometric (b>3) in the monsoons season while in the pre- and post-monsoon the growth was reported as significantly negative allometric (b<3). The negative allometric growth shows that the fish are unable to maintain their shape in the specific season. It is suggested to stop the fishing activities for marine catfishes during the spawning and oral incubation period in pre-monsoon especially from February to mid-April to ensure sustainable fishing with a better growth dynamic.