Backbone Mechanics of the Blue Marlin <i>Makaira Nigricans</i> (Pisces, Istiophoridae)

Abstract

ABSTRACT Over most of its length, the backbone of the blue marlin, like that of all other istiophorids, contains enlarged and flattened neural and hemal spines and zygapophyses, all of which span the intervertebral joints. These plates of bone restrict dorso-ventral bending of the backbone but their arrangement permits a high degree of lateral flexion. The spines and zygapophyses also appear to be important in stabilizing the relatively large intervertebral joints against axial compression and lateral shearing during bending. Although bone is an elastic material, these overlapping structures are not arranged so as to contribute to elastic recoil of the backbone during normal swimming movements.