Meeting Abstract

P1.208  Saturday, Jan. 4 15:30  Sea slug geometry and toxic chemical defense: a novel application of 3D imaging MATSUDA, S.S.*; GOSLINER, T.M.; California Academy of Sciences and San Francisco State Univ.; California Academy of Sciences smatsuda@calacademy.org

Brightly colored sea slugs that live in the most biodiverse and threatened coral reefs on the planet also possess unique evolutionary novelties in defense and shape. A group of opisthobranch molluscs called nudibranchs have evolved hyperbolic geometry, a unique structural shape characterized by negative curvature. This is evident in the elaborate undulations surrounding their bodies that provide a higher surface-area-to-volume ratio than flat or positive curvature. Nudibranchs have also developed the unique ability to reuse toxic chemical defense compounds stolen from their prey for their own defense. These compounds are stored in glands lining the edge of the undulations in the best position to fend off an attacker. These toxic chemical compounds aid in nudibranch prey identification and some have been discovered to have biomedical properties. The relationship between nudibranch geometry and types of chemical compounds will be examined by i) updating the Glossodoris phylogeny with mitochondrial genes CO1 and 16S and nuclear genes H3 and 28S, ii) reviewing the literature for chemical data for described and new species of Glossodoris, and iii) measuring hyperbolic geometry by creating a new 3D imaging technique for soft bodied invertebrates and analysis via geometric morphometrics. Uncovering a relationship between geometry and distribution of defensive glands in nudibranchs would reveal insights into the evolution of shape and chemical defense sequestration, the role local environmental pressures play in chemical sequestration and shape, and the effectiveness of defense mechanisms located within nudibranchs’ tissues.