Systematic review of the “ Chromodoris quadricolor group” of East Africa, with descriptions of two new species of the genus Chromodoris Alder & Hancock, 1855 (Heterobranchia, Nudibranchia)

The similarities and variations in nudibranch species of the “ Chromodoris quadricolor group” (Heterobranchia, Nudibranchia) have historically created identification problems among both nudibranch enthusiasts and experts. In this study, we combine molecular genetic analyses using one nuclear gene ( histone h3 ) and two mitochondrial genes ( cytochrome c oxidase subunit I and ribosomal 16S RNA ) with morphological data to ameliorate the identification of specimens from this complex in East Africa. We include a detailed examination of polymorphisms within the group. As a result, Chromodoris boucheti is synonymized with Chromodoris lochi , and two new species are described, Chromodoris celinae sp. nov. and Chromodoris helium sp. nov. Chromodoris celinae sp. nov. is a common shallow water species that was previously misidentified as C. hamiltoni. Chromodoris helium sp. nov. is a species that appears to be restricted to depths below 30 m. This study agrees with previous research indicating the recent divergence of the genus Chromodoris .