Meeting Abstract

P1-72   -   Bite Force Estimates for Greenland Sharks using Anatomy and Modeling Sawant, S*; Ferry, L; Ronan, A; Arizona State University ssawant5@asu.edu https://morphology.asu.edu/

Bite force is a measure of feeding performance, linking the anatomical form to a function. Using jaw muscle fiber angles and mass, bite force can be calculated using assumptions from basic Newtonian physics. This method of predicting organismal performance has been validated in multiple taxa to include crocodilians, fishes, elasmobranchs, and more. Therefore, this is a useful and reliable way to study performance in species that are not amenable to capture or captivity. The goal of this study is to estimate maximum bite force generated by the Greenland shark, Somniosus microcephalus, and to compare these estimates with both close relatives and other large sharks. Three greenland sharks were obtained and had an average length of 85.7cm (52-109cm). The jaw adductors were exposed, photographed, excised, and weighed. Muscle fiber angles, and lengths of the in- and out-levers (formed by the insertion of these muscles onto the lower jaw) were measured using the program FIJI. These were subsequently used to calculate power output, or bite force, following previously published protocols. These estimates were compared with estimates from Mako, Spiny dogfish, and Sandbar sharks, for whom bite force was estimated using the same protocols, in previous studies. The average maximum bite force for Somniosus microcephalus was 22.18 N (SD = 3.92), which was most similar to the spiny dogfish sharks selected for comparison; perhaps predictable given similarities in morphology and a close phylogenetic relationship. Generally speaking, the bite force estimates for Greenland sharks were as expected (bite force increasing with size), or slightly on the low side, when comparing bite force with body size among these species of sharks.