ABSTRACT
Perhaps the most remarkable thing about the elasmobranch feeding mechanism is its functional diversity despite its morphological simplicity. Compared to the teleost skull, which has approximately 63 bones (excluding the branchiostegal, circumorbital, and branchial bones), the feeding apparatus of a shark is composed of just 10 cartilaginous elements: the chondrocranium, paired palatoquadrate and Meckel’s cartilages, hyomandibulae, ceratohyal, and a basihyal. Furthermore, the elasmobranchs lack pharyngeal jaws and the ability to further process food by this secondary set of decoupled jaws as do bony shes. Despite this, sharks, skates, and rays display a diversity of feeding mechanisms and behaviors that, although they do not match those of the
bony shes, is truly remarkable, especially considering there are only approximately 1100+ species of elasmobranchs compared to about 24,000 species of teleost shes (Compagno, 2001; Compagno et al., 2005; Nelson, 1994). The elasmobranchs capture prey by methods as diverse as ram, biting, suction, and lter feeding, and they feed on prey ranging from plankton to marine mammals and giant squid (Cherel and Duhamel, 2004; Frazzetta, 1994; Moss, 1972; Motta and Wilga, 2001; Motta et al., 2010). Understanding the elasmobranch feeding mechanism will shed light on how this functional versatility is achieved and whether or not it parallels that of the bony shes.
