Aspects of Biology and Population Dynamics of Synodontis Schall (Bloch and Schneider, 1801) in River Galma, Nigeria

Department of Fisheries Technology, Akperan Orshi Polytechnic Yandev, Nigeria.

Department of Biology, Ahmadu Bello University Zaria, Nigeria.

Department of Fisheries Technology, College of Agriculture, Science and Technology Lafia, Nigeria

This study investigated the length–weight relationship, condition factor, and population parameters of Synodontis schall in River Galma using standard procedures. Samples collected from July to December 2019 had mean standard lengths of 12.33 ± 0.29cm (females) and 11.98 ± 0.30cm (males), with corresponding mean weights of 49.40 ± 3.60g and 45.80 ± 4.00g. Length–weight regressions indicated allometric growth pattern, with b values of 2.4998 (females), 2.0819 (males), and 2.2589 (combined sex). Standard length and weight were positively correlated (r²). Condition factor (K) values (2.47–2.53) suggested that all individuals were in good physiological condition. The von Bertalanffy growth function produced an asymptotic length (L∞) of 31.50cm. Estimated total mortality (Z), natural mortality (M), and fishing mortality (F) were 2.150, 0.994, and 1.156, respectively. Although males were more numerous, no
significant difference in sex ratio (P >0.05) was observed.

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