The "Threespot barb," Barbus trimaculatus, is another small barb found over a wide area of sub-Saharan Africa, from the upper Congo to the east coast in Tanzania and south to Natal, South Africa. In Jackson's (1961) checklist, this species is assigned only to his "Zone III" (the lower reaches of rivers). However, it definitely occurs in sheltered near-shore areas of Lake Malawi proper, as well as in marshes and swamps adjacent to the lakeshore. Worthington (1933) reported 21 specimens from Vua, from the southwest arm, and from Bar House (lower southeast arm). Moreover, Konings (1990a: 473) includes a photograph of an individual collected at Kande Island, just offshore along the central west coast of Lake Malawi.
Jubb (1967) describes the coloration as follows:
Barbus trimaculatus is insectivorous (FishBase; Worthington, 1933). Food items identified in stomachs include caddisfly and mayfly larvae, dragonfly nymphs, adult water beetles, and the seeds of plants. This barb reaches a length of 15 cm (6 inches) in some parts of its distribution, but Jackson (1961: 549) notes that it "[g]rows to about 10 cm. [4 inches] but usually less." The species summary at FishBase states that it occurs "... in shallow water near river outlets or close to swampy areas.... Hardy, commonly occurs in a wide variety of habitats, especially where there is vegetation.... Breeds in summer, shoals of ripe adults moving upstream in spate after rain. Females produce as many as 8,000 eggs."
Among the small Barbus species occurring in or adjacent to Lake Malawi, B. trimaculatus is the only one with all of the following characteristics (information from Jackson, 1961: 595):
The above illustration by Hilda M. Jubb is taken from Jubb (1967), and is used here thanks to the generous permission of Mr. A. T. Balkema of A. A. Balkema Publishers, Rotterdam.
|Last Update: 11 August 2000
Web Author: M. K. Oliver, Ph.D.
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