Comparative behavioural assessment of an established and a new tigerfish Hydrocynus vittatus population in two man-made lakes in the Limpopo River catchment, southern Africa

Abstract

With the continued establishment of man-made lakes within the natural distribution range of tigerfish in southern Africa, many artificial tigerfish populations now exist in the region. Very little of the behavioural ecology of these artificial but ecologically important populations is known. Letsibogo and Schroda man-made lakes are two such systems in the Limpopo River catchment. Currently, an established population of tigerfish occurs in Schroda, which is proposed to be used to establish another population in Letsibogo. This study evaluates the suitability of Letsibogo for tigerfish and the behavioural ecology implications associated with an artificial population in the lake. The behaviour of a small population of tigerfish relocated from Schroda to Letsibogo was monitored and compared with the behaviour of the established Schroda population. In Letsibogo the tigerfish established behavioural patterns suggesting that it is suitable to maintain a tigerfish population. To conserve the locally threatened tigerfish in the Limpopo catchment, the establishment of populations in man-made lakes such as Letsibogo is recommended. The effect of tigerfish on indigenous fishes in Letsibogo is unknown and should be considered.