Dendronotus velifer G.O. Sars, 1878

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 : 130

Dendronotus velifer G.O. Sars, 1878

Fig. 7

Dendronotusvelifer G.O. Sars, 1878:238–239 , Pl. 15, Fig. 4 , Pl. 28, Fig. 2 ; Lundin et al., 2017: 303–309, 310–318, Figs 1 , 2, 4 .

Non D. velifer auct. (mix-up with D.robustus and D. bathyvela ).

Extended diagnosis. Body wide. Four to six pairs of branched dorsolateral appendages. Six to twelve main appendages on oral veil. Four to five appendageson rhinophoralstalks. Lateral papilla of rhinophoral sheaths absent orvery small.Rhinophoreswith 12–15lamellae. 30–35 lip papillae. Basal colour commonly light-to bright red with scattered white dots. Dorsal processes of jaws inclined posteriorly at approximately 65° to the longitudinal axis of the jaw body and 0.55 of its length. Masticatory processes with denticles. Radula with up to 36 rows of teeth. Central tooth with low to moderate cusp and up to 26 small distinct denticles without furrows. Up to 15 lateral teeth with which is smooth or with up to four rudimentary denticles. Ampulla twolooped. Bursa copulatrix large, rounded, with small seminal receptaculum placed distally at some distance from the vaginal opening. Prostate discoid with more than 50 alveolar glands. The vasdeferensis moderatein length, penis thin, long. Body length up to 90 mm.

Distribution. North Atlantic (southern limit – Gullmarfjord, Sweden) and Arctic (at least to the Laptev Sea), Norway and Russia.

Bathymetry. Commonly found below 50 m depth, in the Arctic not shallower than 10 m.

Remarks. See Remarks for D. robustus .

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 2 Phylogenetic relationships of the species of the genera Dendronotus, Pseudobornella and Cabangus in single COI, 16S, 28S, and H3 gene trees inferred by Bayesian Inference (BI). Some branches are collapsed. Positions the Pseudobornella orientalis highlighted green; positions the Cabangus regius highlighted orange.Numbers represent posterior probabilities from BI. PHOTOGRAPHS BY A. MARTYNOV AND T. KORSHUNOVA

FIGURE 4 Dendronotus yrjargul sp.nov.(a–n) and D.kalikal (o–t), external and internal morphology.a–c: living holotype of D.yrjargul NTNU-VM-76306 (a) and its habitat (b, c), dorsal,ventral and lateral views with egg mass and associated hydroid Abietinaria fusca, respectively; d: Dendronotus yrjargul, habitat of living paratype NTNU-VM-76302;e: jaw of holotype; f:denticles on the masticatory edge of the holotype; g: jaws of paratype NTNU-VM-76302; h:discoid ridge-like structures on the masticatory edge of paratype NTNU-VM-76302;i: details of discoid structures on the masticatory edge of paratype NTNU-VM-76302; j: anterior part of radula of holotype; k:central teeth of radula of holotype;l:lateral teeth of radula of holotype; m:central teeth of radula of paratype NTNU-VM-76302; n: lateral teeth of radula of holotype; o: living holotype of D.kalikal; p: jaw of D.kalikal, specimen from Kurile Islands;

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