Meeting Abstract

P2.58  Monday, Jan. 5  Fish have GUTS too: The material properties of the intestinal tissues in teleost fishes HORTON, Jaquan M.*; GOSLINE, John M.; Univ. of California, Irvine; Univ. of British Columbia jhorton@uci.edu

Durophagous fishes are predators that specialize in eating hard prey, generally by crushing the shells of mollusks and crustaceans. Others have investigated many of the mechanisms and morphologies that enable fish to consume hard prey and exploit this trophic niche (e.g. dentition and cranial specializations, bite force and mechanical advantages). However, few have examined the effects of hard prey consumption on visceral tissues. If indigestible shell or exoskeletal fragments are consumed, the material properties of the intestinal tissues must withstand the potential mechanical damage caused by sharp foreign bodies (e.g. shell shards) passing through the gut. In this study, we test the hypothesis that the intestines of durophagous fish are more extensible than fish that do not eat hard prey. The whole intestines of six fishes were inflated using a custom, static-pressure system to investigate their material properties. The J-shaped stress-strain curves showed that the initial stiffness ranged from 6 to 60 kPa and that the final stiffness ranged from 4 to 24 MPa. The maximal extension-ratio of the inner lumen ranged between 3.5 and 10.9, and this extension-ratio provides an indication of the size limit for an indigestible shell item or processed unit of food that can travel down the intestine. This work offers significant insight into the material properties of intestinal tissue in teleost fishes. Future studies will focus on the possible adaptive properties of teleost intestinal tissues in a phylogenetic context.