Dendronotus bathyvela Martynov, Fujiwara

User, GBIF. Org, 2021, A synoptic review of the family Dendronotidae (Mollusca: Nudibranchia): a multilevel organismal diversity approach, Contributions to Zoology 90 (1), pp. 93-153 : 113-115

Dendronotus bathyvela Martynov, Fujiwara ,

Tsuchida, R. Nakano, N. Sanamyan, K. Sanamyan, Fletcher & Korshunova, 2020

Fig. 7

Dendronotus bathyvela Martynov et al. 2020a: 507–510 , Figs 4 , 5 .

Extended diagnosis. Body relatively narrow. Extended diagnosis. Body wide. Six to seven Five to six pairs of dorsolateral appendages. pairs of branched dorsolateral appendages. 10 Six to eight appendages of oral veil. Five to to 15 appendages of oral veil. Five appendages six appendages (apparently equal in size) of rhinophoral stalks. Lateral papilla of of rhinophoral stalks. Lateral papilla of rhinophoral sheaths absent. Rhinophores rhinophoral sheaths present. Rhinophores with 15–25 lamellae. Lip papillae 50–70. Basal with 15–18 lamellae. Lip papillae 15–25. Basal colour dull reddish-brownish with numerous colour brownish with scattered distinct distinct opaque white dots on notum, tips opaque white dots. Dorsal processes of jaws of lateral appendages, oral appendages.

inclined posteriorly at approximately 55° Dorsal processes of jaws inclined posteriorly to the longitudinal axis of the jaw body and at approximately 52° to the longitudinal 0.47 of its length. Masticatory processes axis of the jaw body and 0.56 of its length.

apparently bear indistinct denticles (may Masticatory processes apparently bear possess ridge-like structures). Radula with up indistinct denticles (may possess ridge-like to 39 rows of teeth. Central tooth with up to structures). Radula with up to 41 rows of teeth.

14 small denticles and reduced furrows. Up to Central tooth with high cusp and up to 35 nine lateral teeth with up to nine denticles. small distinct denticles without furrows. Up Ampulla folded twice. Bursa copulatrix is to 14 lateral Downloaded teeth from without Brill.com or 12 with /12/2023 few 04 weak:12:08PM via Open Access. This is an open access article distributed under the terms of the CC BY 4.0 License. https://creativecommons.org/licenses/by/4.0/ lateral denticles. Ampulla voluminous, with approximately three loops. Bursa copulatrix large, rounded to oval. Seminal receptaculum small placed distally at a short distance from the vaginal opening. Prostate discoid with about 21–25 alveolar glands. The vas deferens is long, penis elongate, narrow, curved. Body length up to 45 mm.

Distribution. Pacific coast of Northern Honshu, Japan, possibly may occur further in NW Pacific.

jaws with irregular denticles and possibly with ridge-like structures. Radula with up to 32 rows of teeth. Central tooth with deep furrows and with up to 13 distinct denticles. Up to eight lateral teeth with up to ten denticles. Ampulla with three loops. Prostate compact with about nine alveolar glands. Bursa copulatrix large, rounded. Seminal receptaculum large placed distally at considerable distance from the vaginal opening. The vas deferens is moderate in length, penis relatively long, narrow. Body length up to 18 mm.

Bathymetry. A shelf to deep-sea (bathyal) Distribution. Alarcón Rise, Gulf of California, species, so far recorded at depths of 249–510 Mexico, NE Pacific Ocean. m. Bathymetry. 2369 m depth. Remarks. This species has recently been described by Martynov et al. (2020a). Until Remarks. For this recently described deep-sea recently, only the single species D. robustus species there is no additional morphological was recognized among the wide-bodied, information and molecular data is very shallow-water dendronotids of the North limited. In particular, the dorsolateral Atlantic and the North Pacific shelf (Ekimova appendages need a further detailed study. et al.,2015).However, most recent data showed that “ D. robustus ” is a species complex, which Dendronotus comteti Valdés & Bouchet, 1998 was already separated into D. robustus s.str., Dendronotus comteti Valdés and Bouchet , D. velifer and D. bathyvela (Lundin et al., 2017; 1998: 320–323, Figs 1–3 . Martynov et al., 2020a). Diagnosis (original description). Body narrow. Dendronotus claguei Valdés, Lundsten & Two or four pairs of partially branched, Wilson, 2018 partiallyunbranheddorsolateralappendages. Dendronotus claguei Valdés, Lundsten, Wilson , Four to six appendages of oral veil. Four 2018: 412–415, Figs 3B , 9. appendages (similar in size) of rhinophoral stalks. Rhinophores with seven to eight Diagnosis (original description). Body very lamellae.Lateral rhinophoral papilla possibly narrow. Four to six pairs of dorsolateral absent. Lip papillae probably absent. Basal appendages (reported as unbranched). Four colour uniformly pale cream (preserved). appendages of oral veil. Four appendages of Jaws reported as devoid denticles. Radula rhinophoral stalks (innermost appendages with up to 28 rows of teeth. Central tooth from each side longest). Lateral papilla of with deep furrows and with up to ten distinct rhinophoral sheaths absent. Rhinophores denticles. Up to six lateral teeth with up to with 11 lamellae. Lip papillae not reported in five denticles. The reproductive system was original description. Basal colour uniformly not studied in the original description. Body translucent white. Masticatory processes of length up to Downloaded 5. 5 mm from (preserved Brill.com). 12/12/2023 04:12:08PM via Open Access. This is an open access article distributed under the terms of the CC BY 4.0 License. https://creativecommons.org/licenses/by/4.0/

Distribution. Middle Atlantic, Lucky Strike area in the Mid-Atlantic Ridge.

Bathymetry. 1685 m depth.

Remarks. This is the only known species that originated from deep-sea hydrothermal habitats, and which was considered as belonging to the genus Dendronotus according to its external and internal characters. Molecular data is necessary to determine its phylogenetic position.

denticles (may possess ridge-like structures). Radula with up to 51 rows of teeth. Central tooth completely smooth in adults. Up to 16 lateral teeth with up to 19 denticles. Ampulla relatively narrow with several (at least three) loops. Bursa copulatrix very large, oval. Seminal receptaculum small placed distally at a moderately short distance from the vaginal opening. Prostate discoid with up to 50 (and more) alveolar glands. The vas deferens is moderate in length, penis large, wide, with a blunt tip. Body length up to 14 cm.

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. Downloaded from Brill.com 12/12/2023 04:12:08PM via Open Access. This is an open access article distributed under the terms of the CC BY 4.0 License. https://creativecommons.org/licenses/by/4.0/

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. KORSHUNOVADownloaded from Brill.com 12/12/2023 04:12:08PM via Open Access. This is an open access article distributed under the terms of the CC BY 4.0 License. https://creativecommons.org/licenses/by/4.0/

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 Downloadedis marked from on Brill. the commap12/ by 12/ “x” 2023. 04:12:08PM via Open Access. This is an open access article distributed under the terms of the CC BY 4.0 License. https://creativecommons.org/licenses/by/4.0/

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 Downloaded, specimen from Brill from.com Kurile12/12/ Islands 2023; 04:12:08PM via Open Access. This is an open access article distributed under the terms of the CC BY 4.0 License. https://creativecommons.org/licenses/by/4.0/

FIGURE 5 Dendronotus nordenskioeldi sp. nov.ZMMU Op-665, external and internal morphology.a–b:living holotype, dorsal and lateral views respectively;c:ventral view of preserved holotype;d: jaw of holotype; e: irregular denticles on the masticatory edge of the holotype;f:posterior part of radula; g:central teeth of radula; h: lateral teeth of radula of holotype.Scale bars: d: 1mm; e: 20 µm; f:100 µm; g, h: 30 µm. PHOTOGRAPHS BY O. ZIMINA (A, B) AND T. KORSHUNOVA (C). SEM MICROGRAPHS BY A. MARTYNOV

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 Downloaded from Brill.com 12/12/2023 04:12:08PM via Open Access. This is an open access article distributed under the terms of the CC BY 4.0 License. https://creativecommons.org/licenses/by/4.0/