Behaviour of the local killifish : Aphanius fasciatus

Abstract

A sample of eighty-five local killifish was studied in captivity between February 1988 and October 1989. It was found that these fish tend to form schools while feeding, resting, travelling or defending themselves from threatening objects. The school structure is a loose one; its geometric form, size, density and leaders continually change with time. Spawning occurs between May and October and is marked by persistent courtship displays performed by males within the massive algal mats. Smaller males are submissive to larger ones when competing for females, however they still can mate using an opportunistic strategy. Both males and females seem to prefer larger mates as sexual partners. Small amounts of spherical, transparent eggs are produced which are often devoured by adults. Killifish are able to defend themselves by aggregating and matching their body colour to that of their background.