Above: A male mbuna strongly resembling Pseudotropheus elongatus Fryer, 1956, collected with rotenone at Thumbi Island East, Monkey Bay, Malawi, 8 August 1971 by M. K. Oliver and D. H. Eccles (photo copyright © 2001 by M. K. Oliver). The type locality of P. elongatus is Mbamba Bay, on the Tanzania (eastern) shore of Lake Malawi. What appears to be the same species is widespread in the Lake; if the above individual is not the same biological species, it is exceedingly similar, with the correct proportions and male coloration. This is probably the form illustrated by Ribbink et al. (1983) as Pseudotropheus sp. "elongatus aggressive."
According to the diagnosis in Seegers' (1996) redescription, P. elongatus is a member of the relatively short, compact (i.e., deeper bodied) species group of the P. elongatus complex as defined by Ribbink et al. (1983). The diagnosis goes on to state: "It is distinguished from most species of this complex by the combination of the following characters: its deep and short body (body depth 27.7-31.4% SL), the convex forehead profile and the coloration consisting of 7-8 blue vertical bars on a dark brown to blackish back ground in territorial adult males."
Below is a description of the live coloration of P. elongatus at the type locality, Mbamba Bay, Tanzania:
Subadult specimens show a fawn overall coloration with bluish tinges when taken from the water. Underwater, subadult specimens are dark brown to nearly black with 7-8 bluish vertical bars. When kept in aquaria, subadults and subdued fish show a fawn ground color with about 8 bluish vertical stripes [bars]. Territorial males have a dark brown to black ground color with 7-8 blue vertical bars of variable width. Two blue interorbital bars on forehead, lower part of head below eye dark brown to blackish. Pelvics black with anterior edge white. Anal black in its anterior part with the anterior edge white in most specimens, posterior part of anal slightly lighter colored and with 1-8 (mostly 1-4) yellow egg-like spots of various sizes. Dorsal with a white to light blue outer margin. Inner part variable. In some specimens the barring on the body continues to the white margin of the fin, most specimens having a wide submarginal black band. Intermediate phenotypes between the dorsal-fin patterns described do occur. Caudal proximally dark blue to fawn, distally blackish with narrow light blue stripes running along the fin rays. Upper and lower edge of the fin white. Pectorals hyaline to slightly blue. See Spreinat (1994: 251) for underwater photographs of male and female (as Pseudotropheus "Elongatus Sand") from the sunken pontoon at Mbamba Bay. The specimen shown on page 249 in Spreinat (1994), bottom left, clearly is of the same species; the bottom right picture seems to be P. elongatus as well. (Seegers, 1996: 103-104)The above coloration may be compared with that of the recently described P. longior.
Take a look at the Gallery of Pseudotropheus Species Resembling P. elongatus for some color photos, and pointers to the pages illustrating still other forms named as separate species.
The drawing below, from fig. 9 of
Ribbink et al. (1983), shows a Ps. elongatus
from Nkhata Bay (Malawi); reproduced by permission of the
Zoological Society of Southern Africa.
|Last Update: 1 June 2008
Web Author: M. K. Oliver, Ph.D.
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