A male Caprichromis orthognathus. This distinctive species has been
observed to be a head-ramming paedophage, or robber of fry
(McKaye & Kocher, 1983).
Below: Another individual of C. orthognathus. (Text and
additional photos further below.)
Below: Closeups of the head, showing the closed, and the
widely opened, jaws and the steeply inclined gape, which is nearly vertical.
The upwardly opening mouth of this species is quite unusual,
and is an adaptation that probably evolved together with its highly specialized
feeding behavior of ramming, from below and behind, the throat area of female
cichlids that are brooding eggs or larvae, forcing them to expel their brood.
(Mouthbrooding female cichlids are easy to recognize, as aquarists know,
because the floor of the mouth becomes visibly distended downward.)
Photos in this series were used in Fig. 1 of McKaye & Kocher (1983)
to illustrate this individual with and without its oblique stripe, which it can
"turn on" and "turn off," depending on whether its prey of the moment is an
oblique-striped species or not. (Thus, C. orthognathus is an aggressive mimic,
relying partly on confusing its prey into regarding it as conspecific in order to
swim close enough to strike.)
All photos copyright © by M. K. Oliver.
|Last Update: 13 August 2001
Web Author: M. K. Oliver, Ph.D.
Copyright © 1997-2018 by M. K. Oliver - ALL RIGHTS RESERVED