The post-cranial body armor of the armored Agonidae fishes - How far do the morphological scale modifications go?

Abstract

The family of the Agonidae is characterized by the presence of modified bony scales that form a protecting armor against predators. Despite some very intensive research concerning the skeletal cranial and postcranial anatomy of different Agonids, little information is available in the literature concerning the morphology of these bony scales. In this paper, three common species of the Northeastern Pacific Ocean are microscopically (both stereo and scanning electron microscopy) investigated to show that these bony plates are (a) morphologically different from regular fish scales, (ii) build for strength but also for minimizing the weight of the armor plates and (iii) morphologically different between different species.