The biology of Barbus mattozi Guimaraes (Teleostei: Cyprinidae) in a Zimbabwean reservoir. 2. Growth

Abstract

The growth of Barbus mattozi was investigated in the Mtsheleli Dam, a small Zimbabwean reservoir. Scale rings were found to be a suitable method of determining growth, the rings being laid down in October, just before the rainy season. There was close agreement between growth estimates made from scale rings and those from following the growth of a known-age cohort. Fish in the known-age cohort grew to 12cm (males) and 13cm fork length (females) in two years and eight months while back-calculations from scale rings suggest that after eight years males grew to 27cm and 290g and females to 33cm and 520g. These growth rates were relatively slow and may reflect a shortage of food or poor adaptation to the reservoir ecosystem. Condition varied seasonally, the decline from October to February coinciding with the rainy season when spawning takes place.