Meeting Abstract

P2.55  Friday, Jan. 4  Suction and bite processing mechanics during feeding in spiny dogfish ALLEN, R.M.*; WILGA, C.D.; Univ. of Rhode Island ; Univ. of Rhode Island rallen@mail.uri.edu

Although, recent feeding studies have focused on capture mechanisms in elasmobranchs, similar studies on prey processing behavior are lacking. Prey processing in elasmobranchs can involve biting, spitting, suction and crushing or combinations thereof. To investigate this, cranial and branchial kinematics, which are directly responsible for suction and compression generation, and associated pressures were compared during suction and bite processing in four spiny dogfish, Squalus acanthias. Sonometric crystals were implanted on the upper jaw, lower jaw, anterior and posterior cranium and hyoid arch. Pressure in the buccal and pharyngeal cavities was recorded simultaneously with the kinematics. As the gape decreases, positive pressure in the buccal cavity begins to increase in bite processing events. Positive pressure peaks in the buccal and pharyngeal cavities at the time of jaw closure. Hyoid depression and lateral width, and therefore hyoid area, begins to decrease prior to jaw closure. In contrast, during suction processing, gape and hyoid area increases generating negative pressure in the buccal and pharyngeal cavities. Peak pressure occurs variably between the onset and peak gape. Similar to suction captures, hyoid depression increases while lateral width decreases during suction processing. The time of hyoid arch movement is modulated between biting and suction processing events leading to positive or negative generation of pressure as desired. Spiny dogfish exhibit generalist processing mechanisms as well as foraging and capture behaviors as has been found in other studies.