The evolution of the premaxillary protrusion system in some teleostean fish groups
Article first published online: 20 AUG 2009
Journal of Zoology
Volume 193, Issue 1, pages 11–23, January 1981
How to Cite
Gosline, W. A. (1981), The evolution of the premaxillary protrusion system in some teleostean fish groups. Journal of Zoology, 193: 11–23. doi: 10.1111/j.1469-7998.1981.tb01487.x
- Issue published online: 20 AUG 2009
- Article first published online: 20 AUG 2009
- Accepted 12 February 1980
Changes in the acanthopteran (acanthopterygian) system of premaxillary protrusion are traced from its incipient representation in the iniomous (myctophiform) genus Aulopus to its fully evolved form in the percoids. Two complementary components of the system are differentiated. One is the protrusion of the premaxillary, brought about primarily by the anteroventral movement of a ligament attached to the rostral cartilage. The second, which distinguishes the acanthopteran system from other types of jaw protrusion, is the emplacement of a bony maxillary wedge between the skull and the protruded premaxillary.
The acanthopteran type of protrusion appears to have evolved in large-mouthed fishes, with the lateral expansion of the gape that occurs in such forms a fundamental element of this system's mechanics. The modifications that occur in small-mouthed fishes with little or no lateral expansion of the gape are discussed.
Premaxillary protrusion was investigated in available fish groups sometimes placed between the iniomous fishes and the percoids in classifications. Of these groups, the beloniform and cyprinodont fishes have developed protrusion systems of non-acanthopteran types.