Dendronotus arcticus Korshunova, Sanamyan, Zimina, Fletcher & Martynov, 2016

Korshunova, Tatiana, Bakken, Torkild, GrØtan, Viktor V., Johnson, Kjetil B., Lundin, Kennet & Martynov, Alexander, 2021, A synoptic review of the family Dendronotidae (Mollusca: Nudibranchia): a multilevel organismal diversity approach, Contributions to Zoology 90 (1), pp. 93-153 : 113

Dendronotus arcticus Korshunova, Sanamyan, Zimina, Fletcher & Martynov, 2016

Fig. 7

Dendronotusarcticus Korshunovaet al., 2016a: 26–28 , Figs 1 , 3A .

Extended diagnosis. Body relatively narrow. Five to six pairs of dorsolateral appendages. Six to eight appendages of oral veil. Five to six appendages (apparently equal in size) of rhinophoral stalks. Lateral papilla of rhinophoral sheaths present. Rhinophores with 15–18 lamellae. Lip papillae 15–25. Basal colour brownish with scattered distinct opaque white dots. Dorsal processes of jaws inclined posteriorly at approximately 55° to the longitudinal axis of the jaw body and 0.47 of its length. Masticatory processes apparently bear indistinct denticles (may possess ridge-like structures). Radula with up to 39 rows of teeth. Central tooth with up to 14 small denticles and reduced furrows. Up to nine lateral teeth with up to nine denticles. Ampulla folded twice. Bursa copulatrix is large and rounded. Seminal receptaculum small placed distally at a moderately short distance from the vaginal opening. Prostate discoid with about 25–30 alveolar glands. The vas deferens is moderate in length, penis long and twisted. Body length upto 19 mm.

Distribution. Arctic – Kara Sea to Laptev Sea, Russia.

Bathymetry. 10–20 m depth, occasionally deeper.

Remarks. This recently described species is easily distinguished from its congenerics ( Korshunova et al., 2016a).This is a true Arctic species that so far has been recorded only from the Laptev Sea and Kara Sea.

Figures

FIGURE 1 Phylogenetic relationships of the species of the genus Dendronotus based on COI + 16S + 28S + H3 concatenated dataset inferred by Bayesian Inference (BI). Numbers represent posterior probabilities from BI and bootstrap values for Maximum Likelihood.Some branches are collapsed at species level.Dendronotus elegans from the type region (North Atlantic) are highlighted in dark purple. Abbreviations:h – holotype; p – paratype.Summary of species delimitation results from ABGD analyses for the COI dataset is shown

FIGURE 3 A.Map of the Northern Hemisphere showing the distribution of D.elegans (including “D.niveus”), D.kalikal, and D.yrjargul sp. nov.The type locality of D.elegans is indicated by crossed lines. B. The haplotype networks based on cytochrome c oxidase subunit I (COI), 16S rRNA (16S), and 28S rRNA (28S) molecular data showing genetic mutations occurring within D.elegans (“D.niveus”), D. kalikal, and D.yrjargul sp. nov. specimens.Abbreviations:BeSt – Bering Strait; BS – Barents Sea; Gr – Greenland; Km – Kamchatka; KS – Kara Sea; Ku – Kuril Islands; LS – Laptev Sea; Nf – Newfoundland; NS – Norwegian Sea; WS – White Sea.Type locality of D.elegans is marked on the map by “x”.

FIGURE 7 Representaives of the genus Dendronotus (living specimens). PHOTOGRAPHS BY T. KORSHUNOVA, A. MARTYNOV, K. FLETCHER, D. MILLER, Y. FUJIWARA, K. HASEGAWA, K. SANAMYAN, N. SANAMYAN, AND O. ZIMINA