Meeting Abstract

54.10  Saturday, Jan. 5  Do the pharyngeal jaws of moray eels constrain their oral jaw diversity and trophic ecology? MEHTA, Rita S; University of California, Davis rsmehta@ucdavis.edu

The pharyngeal jaws of moray eels are highly specialized for transporting prey from the oral cavity into the oesophagus. The moray pharyngeal jaws represent a functional innovation which permits morays to feed on large prey. However, unlike the pharyngeal jaws of cichlid fishes that are efficient at breaking down prey and have recently been shown to play an important role in the evolution and diversification of cichlid fishes, the pharyngeal jaws of morays may have constrained their oral jaw diversity. Because of the pharyngeal jaws� specialized role in prey transport and loss of some ancestral functions, which presumably included prey processing, moray oral jaws may have been restricted to be efficient at either prey capture or processing, which would result in two discrete clusters of cranial form and diet. I tested this hypothesis by examining morphological characters of the oral jaws and the pharyngeal jaws of morays representing the range of moray trophic habits. Although there are over 200 species of moray eels, accounts in the literature reveal that the dietary habits of morays can be divided into three classes: fish, unshelled-mollusks and hard-shelled mollusks and crustaceans. Durophagous morays are the only morays known to process prey in their oral jaws and they exhibit distinct force-modified oral jaw features that separate them from piscivorous eels in morphospace. Thus far, durophagous morays are the only known morays equipped to process prey in their oral jaws. Thus, pharyngeal jaw specialization may have constrained oral jaw diversity in moray eels as the oral jaws of morays functionally grouped into either those modified for �prey- processing� or �prey-capture�.