This strikingly marked predatory cichlid is Tyrannochromis nigriventer, named by
David Eccles in 1989. I captured it along with T. Kocher and K. McKaye at Nkhata Bay (northern
L. Malawi) on 23 July 1980, by chasing it into a small-mesh gill net on rocky shore off the tip of
the peninsula separating the north and south bays, at a depth of
25 feet (7 meters). Photo copyright © by M. K. Oliver.
Nkhata Bay is the type locality; the holotype (BMNH 1956.6.4:6) had been collected in the mid-1950s by the Joint Fisheries Research Organisation, whereas the paratype and largest known specimen of this rarely collected but widely distributed species, a ripe female of 163 mm SL collected by Rosemary H. Lowe in the mid-1940s, was caught at Monkey Bay, in the southern part of the lake. The individual in my photograph seems to be only the third known museum specimen, and is in the collection of the US National Museum of Natural History. Konings (1995: 101) reports a large population of T. nigriventer at Maingano, Likoma Island.
Eccles (in Eccles & Trewavas, 1989) presented anecdotal evidence from Andreas Spreinat suggesting that this cichlid may be a paedophage, forcibly extracting fry from the mouths of brooding female cichlids. Eccles remarked, "...the large mouth, thickened lips and small, embedded teeth appear to be suitable for such a role." Eccles further remarked,
Breeding males of T. nigriventer are commonly seen about September defending large "nests", often exceeding 1 metre in diameter, excavated in sand below overhanging boulders. These have previously been referred to in the literature as Haplochromis macrostoma (e.g. Axelrod & Burgess, 1983: 158-159) or Cyrtocara macrostoma (Lewis et al., 1986: 39).However, Konings (1995: 113) observed that "T. nigriventer hunts by stealth, ambushing its prey from behind a rock. It moves slowly forward and suddenly opens its wide gape. Mbuna of up to 6 cm have been found in the stomach of this predator." Additional detailed observations of spawning are available in Konings (loc. cit.).
|Last Update: 14 December 2003
Web Author: M. K. Oliver, Ph.D.
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