Fishery biology of Chrysichthys longidorsalis (Risch and Thys Van Den Audenaerde, 1981) landed at the Sanaga River, Cameroon

Cameroon’s fishery resources are under increasing pressure due to overfishing and inadequate management strategies, necessitating research into indigenous species with potential for both sustainable fisheries and aquaculture development. The present research, carried out from November 2019 to October 2020, was aimed at investigating the fishery biology of Chrysichthys longidorsalis landed at Sanaga River, to provide baseline information for its fishery management and aquaculture development. 451 specimens were examined, identified and their lengths and weights measured. Bhattacharya’s method was used to age the fish and assigned age at length groups used to estimation von Bertalanffy growth parameters. Growth performance index was estimated alongside fishery parameters. C. longidorsalis population exhibited a short lifespan (maximum 4 years) with rapid growth and heavily skewed toward age group 1 (75.66%), suggesting high recruitment with intense exploitation of juveniles.  The von Bertalanffy growth parameters (L∞ = 55.25 cm TL, K = 0.41 year?¹, t? = -0.24) indicate moderate growth and early maturation. Growth performance index (Φ? = 2.64) confirmed satisfactory growth conditions. Current exploitation rate (E = 0.44) exceeds optimal level (Eopt = 0.366), signalling overexploitation. Z/K ratio of 4.63 further confirms that fishing induced mortality dominates growth. Increasing gillnet mesh size to 76 mm, enforcing minimum legal size limits (≥23.97 cm TL), introducing seasonal closures and integrating inland fisheries into national policy will support long-term sustainability of this species. Key words: Chrysichthys longidorsalis, fishery biology, Sanaga River, Cameroon.