Comparative Study of Sociability Preferences and Phototactic Response of Fingerlings and Juvenile African Catfish (clarias Gariepinus)

The African catfish (Clarias gariepinus), a freshwater species known for its adaptability and negative phototaxis, often forms social groups and prefers darker environments. This study investigated the sociability and phototactic responses of C. gariepinus fingerlings and juveniles to understand behavioural traits relevant to aquaculture. Eighty healthy fingerlings (mean weight: 4g, mean length: 5cm) and 80 healthy juveniles (mean weight: 10g, mean length: 8cm) were obtained and acclimatised for two weeks. Sociability and phototactic responses were analysed using a Generalised Linear Model (GLM). Results showed a significantly higher behavioural response in the sociability test, confirming the species' strong preference for social environments. Although no significant difference was observed between developmental stages, juveniles exhibited increased behavioural activity when isolated. Phototactic tests revealed that both fingerlings and juveniles strongly preferred dark environments, which significantly increased behavioural responses. Notably, sociability and phototaxis appeared to be independent behavioural traits, with no significant interaction detected between them. The study concludes that C. gariepinus exhibits strong sociability and negative phototactic behaviour across developmental stages, with the presence of conspecifics significantly enhancing behavioural activity, underscoring the species' inherent social tendencies.