Meeting Abstract

18.3  Jan. 5  Eating big: Innovation in the moray eel feeding mechanism MEHTA, R.S*; WAINWRIGHT, P.C.; Univ. of California, Davis; Univ. of California,Davis rsmehta@ucdavis.edu

Suction feeding is ubiquitous among aquatic vertebrates. We report the discovery that a major radiation of teleost fishes, the moray eels of the anguilliform family Muraenidae, do not use suction to capture prey. Suction feeding is characterized by a series of quick tightly integrated movements that rapidly expand the buccal cavity to generate a water flow that moves the prey into the mouth. In a kinematic evaluation of prey capture mechanisms we measured no movement of prey toward eels. Morays exhibit several major anatomical novelties of the head region associated with the absence of suction during prey capture, including reduction of the hyoid bar, pectoral girdle and sternohyoideus muscle. We tested the hypothesis that the loss of suction feeding has freed temporal constraints on prey capture kinematics by comparing two moray species to four suction feeding teleosts: a suction feeding anguillid eel, two centrarchids, and a cichlid. While all six species showed a similar sequence of kinematic events during prey capture, the moray cranial movements were significantly slower compared to the suction feeders. In addition, morays frequently reversed the direction of jaw and cranial rotation in the midst of the strike, something that has never been reported in a suction feeding fish. Timing variables alone represented 65% of the feeding variation observed across the six taxa in kinematic space. Morays also showed significantly higher variance in kinematic variables than the four suction feeders. The absence of suction feeding as a prey acquisition behavior in morays not only permits temporal variation in feeding kinematics but increased functional capacity of the pharyngeal jaw apparatus. Morays appear to have modified the general teleost feeding patterns in order to eat big prey.