The development, function, and design of amphicoelous vertebrae in teleost fishes


  • Laboratory of T. H. Frazzetta.

Division of Vertebrate Paleontology, Smithsonian Institution, Washington, D.C. 20560, U.S.A.


The vertebral centra of teleost fishes are amphicoelous. They resemble biconid hour-glass shaped cylinders, the ends of which are concave.

The development, function, and design of the biconid amphicoelous shape of teleost centra are discussed in view of: the role of morphogenesis in the development of centra shape; function of the precaudal portion of the vertebral column in teleost locomotion; design of the centra as an adaptive response to functional problems.

The biconid portion of the centrum is formed in compact bone by ossification within the cylindrically arranged sclerotome. The characteristic biconid shape is controlled by alternating dilation and constriction of the developing anlage, a result of differential growth of the sclerotome and notochordal sheaths. The shape of the biconid compactum is not correlated with stress distributions resulting from locomotion.

Much spongy bone is present in teleost centra; it surrounds the compact biconid and forms longitudinal bars of bone along the lateral margin of the centra. Spongy bone is derived from sclerotomal mesemchyme. The time for formation, its position, and alignment of bony trabeculae within the spongy bone suggests it to be deposited in response to mechanical stresses.