Increased potential versatility in form and function of the feeding apparatus of cichlid fishes has led to a prodigious proliferation in the number of possible functional solutions to an increasing variety of biological problems. Optimal utilization of every conceivable trophic resource in lacustrine environments by just one fish family, the Cichlidae, has been achieved by eruptive evolutionary radiation within the characteristically cichlid body plan producing mechanisms which partition the diverse food resources with extraordinary efficiency therefore minimizing resource sharing. There is a direct relationship between the effectiveness of trophic resource exploitation and the functional integration of the cichlid body plan in which a minimum numher of adaptive compromises are necessary to evolve optimal anatomical solutions by rapidly realizable changes.
Anatomical data presented here reveal that cichlids possess a specific kind of mosaic in which the basic percoid jaw apparatus permits unparalleled optimal adaptations by simple morphogenetic changes while unique and dramatically diverse patterns of muscular coordination involving degrees of synchrony ancl extensive modulating capabilities of antagonistic muscle groups have been discovered electromyographically. At the same time the highly integrated pharyngeal jaw apparatus is sufficiently specialized providing complete freedom for the jaws to evolve into refined collecting devices.
The exceptional evolutionary success of lacustrine cichlids demonstrates how rare and very
specific kinds of biologically versatile morphological mosaics represent the best
preadaptations for the ancestors of major new taxa. Given identical ecological conditions
and temporal factors, a group of organisms possessing such rare mosaics, in which optimal
biological versatility is realizable by simple evolutionary mechanisms, will dominate newly
formed environments to the detriment of taxa not so endowed.