A PRELIMINARY STUDY OF ASPECTS OF THE ECOLOGY OF A RARE MINNOW BARBUS TREURENSIS GROENEWALD, 1958 (PISCES: CYPRINIDAE) FROM THE EASTERN TRANSVAAL, SOUTH AFRICA

Abstract

The habitat preferences, food habits, reproduction, age and population size of Barbus treurensis were investigated as part of a survey of the threatened fish of the Transvaal. Barbus treurensis occurs only in an isolated section of the Blyde River tributary of the Limpopo system, eastern T'ransvaal, where it generally inhabits rocky-bottomed pools with cool, clear water. It feeds mainly on aquatic invertebrates but also ingests filamentous algae and can be considered to be a facultative feeder. Due to the difficulty of sampling a small fish such as B. treurensis in a comparatively large stream, it was not possible to make accurate estimates of population size. It is estimated, however, that a total population in excess of 25 000 individuals was present in the stream during the survey. Barbue treurensis reaches a maximum age of six years, breeds during October/November and has a reIatively low maximum fecundity in the region of 2 000 ova. The life history strategy of B. treurensis is discussed and it is concluded that like most other fishes inhabiting relatively unstable habitats, such as mountain streams, B. treurensis is primarily an r-strategist.