Upper fish: One of the scale-scraping aggressive
mimics of Lake Malawi, the haplochromine cichlid Corematodus
shiranus. Lower fish: Its model and chief prey, which is only very
distantly related to ita member of the endemic Malawi tilapia
species flock, which includes Oreochromis
("Nyasalapia") squamipinnis and several related species.
Photo copyright © 1997 by M. K. Oliver.
Note how convincingly the haplochromine's color pattern resembles
that of the tilapiine, from the bright silvery ground color to the
irregular outlines of the black bars. It is this similarity,
together with behavioral mimicry, that permits the Corematodus
to swim (in relatively low numbers) among shoals of Oreochromis,
approach them, and rapidly bite at the caudal fin, rasping small
epithelium-covered scales from the fin. These scales seem to
constitute the chief diet of the two known Corematodus species;
hundreds of the scales are found in the gut contents
(Fryer & Iles, 1972).
Be sure to look at the peculiar jaws and dentition characterizing
this genus, as illustrated for the other species,
Corematodus taeniatus.
Last Update: 16 November 2000
Web Author: M. K. Oliver, Ph.D.
Copyright © 1997-2021 by M. K. Oliver, Ph.D. - ALL RIGHTS RESERVED