Seeing double: pseudocryptic diversity in the Doriopsilla albopunctata-Doriopsilla gemela species complex of the north-eastern Pacific

Molecular analyses of samples of Doriopsilla albopunctata and its twin' species Doriopsilla gemela collected from their entire geographic ranges in the north-eastern Pacific revealed an unexpected level of species diversity. Species delimitation analyses recovered five distinct species in the complex. When the specimens were re-examined morphologically in the light of the molecular results, some external and internal differences between them became evident; thus, these species are considered pseudocryptic. The ranges of the three species previously named D.albopunctata overlap partially or entirely, and this along with anecdotal evidence of prezygotic isolation suggests sympatric speciation may be at play. On the contrary, the ranges of the two species previously named D.gemela do not overlap and their developmental modes differ. A review of the literature was conducted to clarify the taxonomy of the species complex, and we concluded that two available names (D.fulva and D.gemela) can be confidently assigned to two of the species. The original description of D.albopunctata is ambiguous, but the common usage of the name is fixed herein with the designation of a neotype for the most common intertidal southern California species. Finally, two new names are introduced for the remaining two species.