Meeting Abstract
Chromodorid nudibranchs are brightly colored sea slugs that live in some of the most biodiverse and threatened coral reefs on the planet. These sea slugs’ vibrant colors can serve as a warning signal to predators of their toxic chemical defenses, or allow the slugs to blend seamlessly into their surroundings. Nudibranchs in the genus Glossodoris (Mollusca: Gastropoda: Opisthobranchia: Chromodorididae) exhibit diverse color patterns and are a model group for examining the evolution of color pattern and shape. However, a recent mitochondrial phylogeny of the Chromodorididae revealed Glossodoris to be polyphyletic. In this study, 50 individuals comprising 18 taxa were used to build a more robust phylogenetic tree of Glossodoris and related clades. Molecular phylogenetic analyses were performed on mitochondrial genes COI and 16S, and nuclear gene 28S. Maximum likelihood and Bayesian statistical analyses were conducted to support the hypothesized evolutionary relationships within Glossodoris. Molecular and morphological data reveal a cryptic species complex within Glossodoris cincta, with distinct species arising from the Indo-Pacific and the east coast of Africa. Next steps include morphological analysis of radular structures and reproductive systems to confirm the distinct new species. Glossodoris cincta are large, common nudibranchs with a widespread range. The molecular identification of cryptic species allows for the recognition of subtle variations in color pattern and external characters that will help with in-field identifications. The discovery of cryptic species within Glossodoris cincta accentuates the likelihood that more undescribed species are hiding within previously defined taxa; this has strong implications for color pattern evolution, the evolution of chemical defense sequestration, and biomedical prospecting.
