Haplochromis argens is a pelagic species from the littoral and sub-littoral zone (Ref. 92860). At night the species is virtually restricted to the two upper metres of the water column; by day, the highest densities were found at two to three metres from the surface, but individuals of this species were also caught with bottom trawls over sand and mud bottoms, and in gill nets and traps near rocks (Ref. 92860).Before the ecological changes in Lake Victoria, the diet of H. argens comprised mainly zooplankton during the day; Chaoborus larvae were important at night (Ref. 92860). The current diet is unknown, but all the studied resurgent species in the Mwanza Gulf changed their diet (Ref. 92860).Haplochromis argens is a female mouth brooder (Ref. 92860). Spawning sites are located at depths less than 9 metres (Ref. 92860).