ИСТИНА

Dorids (Doridida) are a large group of nudibranch molluscs, and their phylogeny and evolution is not yet well understood. Recently, a series of papers presented morphological and ontogenetic evidences for a cryptobranchiate (i.e. with gill cavity and retractable gills) common ancestor of all dorids (e.g. Martynov and Schrödl, 2011; Martynov and Korshunova, 2015). This view was partially challenged most recently applying genetic data for a reorganization of onchidoridoid systematics (Hallas and Gosliner, 2015). However, some crucial taxa were missing in the latter analysis. Here we show that the hypothesis of a common cryptobranch dorid ancestor still is a valid conception. We emphasize that the genus Onchimira on one hand has all unique apomorphies of the otherwise phanerobranchiate family Onchidorididae, such as unique patterns of the radula and buccal pump; but simultaneously it possesses a true gill cavity with fully closable edges as in the majority of the cryptobranch dorids. Molecular data on Onchimira is presented here for the first time and confirms its placement within Onchidorididae. The family thus includes cryptobranch and phanerobranch members; there is no need to restore a separate family Calycidorididae for two genera with reduced gill cavity, as proposed by Hallas and Gosliner (2015). Our re-analysis of the Hallas and Gosliner (2015) molecular data with addition of own sequences on all known species of the genus Adalaria show low support for the recently suggested genus Knoutsodonta, and a separate family Corambidae seems redundant. Hallas and Gosliner (2015) also showed close relation between the phanerobranch family Polyceridae and the cryptobranch family Chromodorididae and suggested that this implies a phanerobranch common ancestor. However, the most recent discovery of Elfdaliana, a new genus of Polyceridae with cryptobranch gill cavity (Martynov and Korshunova, 2015), clearly challenges this view. In summary, the phylogenetic and evolutionary hypotheses by Hallas and Gosliner (2015) need to be reconsidered in the light of novel data and discoveries. References Hallas J.M. and Gosliner T.M. 2015. Family matters: The first molecular phylogeny of the Onchidorididae Gray, 1827 (Mollusca, Gastropoda, Nudibranchia). Molecular Phylogenetics and Evolution 88: 16–27. Martynov A.V. and Schrödl M. 2011. Phylogeny and evolution of corambid nudibranchs (Mollusca: Gastropoda). Zoological Journal of the Linnean Society 163: 585–604. Martynov A.V. and Korshunova T.A. 2015. A new deep-sea genus of the family Polyceridae (Nudibranchia) possesses a gill cavity, with implications for the cryptobranch condition and a ‘Periodic Table’ approach to taxonomy. Journal of Molluscan Studies, March, pp. 1–15 doi:10.1093/mollus/eyv003 This work was supported by the Russian Foundation for Basic Research (grant 13-04-01641a), by the Russian Science Foundation (grant 14-50-00029, SEM and molecular study, specimens’ depository), and the DFG (SCHR667/13).