Species delimitation and phylogeny of Doto (Nudibranchia: Dotidae) from the Northeast Atlantic, with a discussion on food specialization

Abstract

The nudibranch genus Doto is taxonomically problematic in particular, and some species are described on the notion of strict monophagy. Here we perform species delimitation on NE Atlantic species, as well as placing them phylogenetically, using two markers: the mitochondrial COI and the nuclear H3. We also study the morphology of the species including radular ultrastructure and review food specificity. Specimens were first divided into potential species using ABDG on both markers, these groups were used as input species for species delimitation analyses using BPP, and analyses were performed with both markers combined and on H3 only. The analyses delimit 11 and eight species, respectively. With the exception of one species for which only COI was available, the differences are found in D. fragilis, which is split into three groups when COI is included and lumped into one with only H3. Doto hystrix is nested within these groups. We also found that specimens from Sweden seemingly close to D. maculata in external morphology have identical sequences as D. coronata. Analysis of food preferences of the species involved in the study contradicts the notion of strict monophagy within Doto.

Biogeographic patterns of distribution of the molluscZelentia ninel(Nudibranchia, Trinchesiidae)

“…Moreover, since 2010, several international collaborative projects on nudibranch molluscs have been implemented around the Norwegian Gulen Dive Resort at Sognefjorden with several significant outcomes. These collaborative works have added significantly to our understanding of the taxonomy of several major nudibranch groups and include the descriptions of new species of Dendronotacea, Trinchesiidae, and Eubranchidae (Korshunova et al, 2017c(Korshunova et al, , 2019(Korshunova et al, , 2020a(Korshunova et al, , 2020bMartinsson et al, 2021) as well as a large monograph on the taxonomy of aeolidacean nudibranchs (Korshunova et al, 2017b). In addition, several recent studies from southern Norway have added to the knowledge on nudibranchs in Norway (Evertsen and Bakken, 2013;Sørensen et al, 2020;Neuhaus et al, 2021).…”

Hidden beauty of the north: a description of Eubranchus scintillans sp.n. (Gastropoda: Nudibranchia) from the Barents Sea and North-East Atlantic

“…Preliminary studies of Eubranchus exiguus in the Barents Sea indicated some variation of the external morphology of specimens. Based on experience with other boreal cladobranch species (Ekimova et al, 2015(Ekimova et al, , 2022aKorshunova et al, 2020;Sørensen et al, 2020;Martinsson et al, 2021) these differences may be interpreted either as intraspecific variation or as interspecific differences. Different researchers argued that it is necessary to be very careful with morphological analysis.…”