Meeting Abstract
P3.71 Thursday, Jan. 6 An Ecomorphological Approach to Understanding Feeding in Butterflyfishes (Chaetodontidae) COPUS, J.M.*; GIBB, A.C.; Northern Arizona University; Northern Arizona University jmc374@nau.edu
We investigate the relationship between morphology and diet in the Lepidochaetodon subgenus of butterflyfish using laboratory studies of several species consuming a variety of ecologically relevant food items. Chaetodon trichrous and C. kleinii possess the typical Chaetodon jaw morphology, with a pointed snout and brush-like teeth. Chaetodon unimaculatus has unusual jaw morphology, with more robust oral jaws and teeth. In the field, C. kleinii and C. trichrous feed in the water column on plankton and also “pick” benthic invertebrates; C. kleinii also feeds on attached benthic prey (Alcyonarians), where available. Throughout most if its range, C. unimaculatus exhibits a similar diet to the other two species; however, in Hawaii this species is a hard coral specialist. In the lab, C. trichrous and C. kleinii both demonstrate a mid-water feeding behavior whereby they approach and orient to the prey, open and protrude their jaws, and engulf the prey with little apparent suction. When feeding on soft coral, fish approach the prey more closely and bite/tear off pieces of the coral using the aforementioned capture behavior, plus a lateral lunge to assist in tearing. Feeding on unattached benthic prey often follows the same pattern as mid-water feeding, but individuals also readily demonstrated the capture+lunge behavior seen in the attached soft coral; in this instance, the lunge behavior serves to remove the prey item from the substrate. Both species show modulation of feeding behavior (i.e., feeding behavior varies with prey type), but, despite differences in jaw morphology, these species demonstrate similar feeding behaviors when presented with the same prey type. Finally, we predict C. unimaculatus, a coral-scraping specialist in Hawaii, will demonstrate a third type of feeding behavior when feeding on hard corals.
