The life history and fishery potential of Labeo umbratus (Teleostei: Cyprinidae) in five small South African reservoirs

• Published in: African journal of aquatic science Vol. 31; no. 2; pp. 285 - 295
• Main Authors: Potts, Warren M, Booth, Anthony J, Hecht, Thomas, Andrew, Timothy G
• Format: Journal Article
• Language: English
• Published: Taylor & Francis Group 01-11-2006
• Subjects: AGE AND GROWTH; Freshwater; Labeo umbratus; LENGTH-AT-MATURITY AND AGE-AT-MATURITY; MOGGEL; SMALL WATER BODIES; South Africa, Inland Waters
• ISSN: 1608-5914; 1727-9364
• DOI: 10.2989/16085910609503898

The life histories of five populations of moggel, Labeo umbratus, inhabiting small Eastern Cape reservoirs were compared and the differences related to environmental parameters. A significant positive correlation between fish growth and chlorophyll a was noted in four cases. In the eutrophic Dimbaza Reservoir, slow growth rate was attributed to intraspecific competition. Mortality was lower in populations living amongst fewer predatory species, and also where food was abundant. Length- and age-at-maturity were not affected by environmental factors, but were dependent on growth and mortality. There was a weak relationship between the fishery potential of L. umbratus populations and algal biomass, and thus it was concluded that populations in small, shallow, slightly enriched reservoirs would be those more suitable for exploitation.