Meeting Abstract

43.6  Sunday, Jan. 5 11:30  Morphology of the Feeding Apparatus in Four Shark Species BALABAN, J.P.*; WILGA, C.D.; Univ. of California, Irvine; Univ. of Rhode Island jbalaban@uci.edu

Sharks have an incredible diversity of feeding mechanisms for a group with so few extant species. To understand the relationship between the morphology of the shark feeding apparatus and feeding style, length, width, and angle of the ten skeletal elements in the feeding apparatus are measured in four shark species (white spotted bamboo, Chiloscyllium plagiosum; spiny dogfish, Squalus acanthias; sandbar, Carcharhinus plumbeus; and dusky smoothhound, Mustelus canis). These species encompass a wide phylogenetic range, and include suction and bite feeders as well as two different orientations of the hyomandibula, the primary jaw support element. A principal components analysis is used to identify relationships among the skeletal elements by species, and linear regressions are then used to test the effect of hyomandibula length on the other morphological variables. Strong relationships were discovered between the length of the hyomandibula and the lengths of all other skeletal elements and the angle of the hyomandibula. Bite feeders have longer elements and appear to maximize the size of the oral cavity, allowing larger prey to be swallowed. Suction feeders have shorter elements, which restrict the size of the oral cavity and mouth opening, but can concentrate suction forces.