Research Article |
Corresponding author: Alexander V. Martynov ( martynov@zmmu.msu.ru ) Academic editor: Nathalie Yonow
© 2016 Tatiana A. Korshunova, Nadezhda P. Sanamyan, Alexander V. Martynov.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Korshunova TA, Sanamyan NP, Martynov AV (2016) Morphological and molecular evidence indicate Dendronotus primorjensis is a valid species that has priority over D. dudkai (Nudibranchia). ZooKeys 634: 15-28. https://doi.org/10.3897/zookeys.634.10231
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Morphological and molecular data of type material of the nudibranch mollusc Dendronotus primorjensis Martynov, Sanamyan, Korshunova, 2015 from the Sea of Japan are summarised and compared with those of D. dudkai Ekimova, Schepetov, Chichvarkhina, Chichvarkhin, 2016. The clear conclusion is that the latter is a junior synonym of Dendronotus primorjensis.
Dendronotus , Gastropoda , Mollusca , Nudibranchia , new synonym
In this publication analysis of combined molecular and morphological data of the holotype and paratype of Dendronotus primorjensis demonstrate that it is a valid species and has taxonomic priority over D. dudkai, published one year later.
Type specimens of Dendronotus primorjensis (ZooBank: http://zoobank.org/2001DB85-2005-4E6F-8A21-F15F9068EC7D) have been described previously (
All specimens of D. primorjensis were examined with a stereomicroscope (MBS-9), a digital camera (Nikon D-90) with a set of extension rings (Kenko), and scanning electron microscope (CamScan Series II) for the original description. The pharynx of the preserved holotype D. primorjensis (
Small pieces of foot tissue of both specimens of D. primorjensis (
Species | Voucher | Locality | GenBank accession nos. | ||
---|---|---|---|---|---|
CO1 | 16S | 28S | |||
Dendronotus primorjensis Martynov et al., 2015 holotype |
|
Russia: Japan Sea | KX672010 | KX672008 | KX672006 |
Dendronotus primorjensis Martynov et al., 2015 paratype |
|
Russia: Japan Sea | KX672011 | KX672009 | KX672007 |
Dendronotus
dudkai
|
W195 | Russia: Japan Sea | KT031811 | KT031824 | KT031841 |
Dendronotus
dudkai
|
W196 | Russia: Japan Sea | KT031812 | KT031825 | KT031842 |
Dendronotus
dudkai
|
W197 | Russia: Japan Sea | KT031813 | KT031826 | KT031843 |
Dendronotus
dudkai
|
W198 | Russia: Japan Sea | KT031814 | KT031827 | KT031844 |
Dendronotus
dudkai
|
W199 | Russia: Japan Sea | KT031815 | KT031828 | KT031845 |
Dendronotus
dudkai
|
W201 | Russia: Japan Sea | KT031816 | KT031829 | KT031837 |
Dendronotus
dudkai
|
W202_1 | Russia: Japan Sea | KT031817 | KT031830 | KT031838 |
Dendronotus
dudkai
|
W202_2 | Russia: Japan Sea | KT031818 | KT031831 | KT031840 |
Dendronotus
dudkai
|
W203 | Russia: Japan Sea | KT031819 | KT031832 | KT031839 |
Dendronotus dalli Bergh, 1879 |
|
Russia: Kamchatka | KM397001 | KM397083 | KM397042 |
Dendronotus dalli Bergh, 1879 |
|
Russia: Kamchatka | KM396999 | KM397081 | KM397040 |
Dendronotus frondosus (Ascanius, 1774) |
|
Norway | KM396976 | KM397056 | KM397017 |
Dendronotus frondosus (Ascanius, 1774) |
|
Russia: Barents Sea | KM396980 | KM397062 | KM397021 |
Dendronotus
kalikal
|
|
Russia: Kamchatka | KM396988 | KM397070 | KM397029 |
Dendronotus
kalikal
|
|
Russia: Kamchatka | KM396986 | KM397068 | KM397027 |
Dendronotus
kamchaticus
|
|
Russia: Kamchatka | KM396989 | KM397072 | KM397030 |
Dendronotus
kamchaticus
|
|
Russia: Kamchatka | KM396991 | KM397073 | KM397032 |
Dendronotus lacteus (W. Thompson, 1840) |
|
Russia: Barents Sea | KM396975 | KM397059 | KM397016 |
Dendronotus lacteus (W. Thompson, 1840) |
|
Russia: Barents Sea | KM396973 | KM397057 | KM397014 |
Dendronotus
niveus
|
|
Russia: White Sea | KM396996 | KM397078 | KM397037 |
Dendronotus
niveus
|
|
Russia: Barents Sea | KM396995 | KM397077 | KM397036 |
Dendronotus
patricki
|
|
USA: California | HQ225828 | HQ225829 | – |
Dendronotus regius Pola & Stout, 2008 | CASIZ179492 | Philippines | HM162708 | HM162629 | – |
Dendronotus robustus Verrill, 1870 |
|
Russia: Barents Sea | KM397002 | KM397084 | KM397043 |
Dendronotus robustus Verrill, 1870 |
|
Russia: Barents Sea | KM397003 | KM397085 | KM397044 |
Doto coronata (Gmelin, 1791) | CASIZ176278 | South Africa | HM162734 | HM162657 | – |
Doto koenneckeri Lemche, 1976 | CASIZ178247 | Portugal | HM162735 | HM162658 | – |
Marionia arborescens Bergh, 1890 |
|
Philippines | KP226855 | KP226859 | – |
Tritonia challengeriana Bergh, 1884 | CASIZ171177 | Atlantic Ocean: Bouvet Island | HM162718 | HM162643 | – |
Two different phylogenetic methods, Bayesian Inference (BI) and Maximum Likelihood (ML) were used to infer evolutionary relationships. Separate analyses were conducted for the following data sets: resulting alignments are 641 bp for COI, 451 bp for 16S, 350 bp for 28S, and 1442 for the concatenated datasets. Evolutionary models for each data set were selected using MrModelTest 2.3 (
The holotype of D. primorjensis (
Dendronotus primorjensis, type material from Zoological Museum MSU: A holotype
These characters are taken directly from
“Body elongate, laterally compressed [the range of the lengths of specimens was not recorded in the description of D. dudkai by
Brief molecular results, including the genetic distances between Dendronotus primorjensis and closely related species were provided in two previous studies (
Phylogenetic analyses were separately performed for COI, 16S, and 28S genes, and three concatenated nucleotide datasets from the holotype and paratype of D. primorjensis, available Dendronotus specimens from GenBank, and an outgroup consisting of four species of Doto, Tritonia, and Marionia (Table
The ABGD analysis of the COI data set run with two different models revealed eleven potential species each:
D. regius (CASIZ179492, CASIZ179493);
D. lacteus (
D. kamchaticus (
D. niveus (
D. dalli (
D. kalikal (
D. venustus (LACM174850);
D. primorjensis (
D. frondosus (
D. patricki (
D. robustus (
The prior maximal distance ranged between 0.001 and 0.059.
The ABGD analysis of the 16S data set run with two different models revealed ten potential species each:
D. regius (CASIZ179493, CASIZ179492);
D. robustus (
D. patricki (
D. kalikal (
D. venustus (
D. frondosus (
D. niveus (
D. lacteus (
D. kamchaticus (
D. dalli (
The prior maximal distance ranged between 0.001 and 0.021.
Results for genetic distances between Dendronotus primorjensis, D. frondosus, D. venustus, D. kalikal, and D. kamchaticus have been described previously (
Uncorrected COI p-distances (%) between holotype and paratype of Dendronotus primorjensis and other species of the genus Dendronotus.
Species |
Dendronotus primorjensis |
Dendronotus primorjensis |
---|---|---|
Dendronotus primorjensis paratype | 0.16 | - |
Dendronotus dudkai KT031811 | 0.16 | 0.31 |
Dendronotus dudkai KT031814 | 0.16 | 0.31 |
Dendronotus dudkai KT031816 | 0.16 | 0.31 |
Dendronotus dudkai KT031819 | 0 | 0.16 |
Dendronotus dudkai KT031812 | 0 | 0.16 |
Dendronotus dudkai KT031813 | 0 | 0.16 |
Dendronotus dudkai KT031815 | 0 | 0.16 |
Dendronotus dudkai KT031817 | 0 | 0.16 |
Dendronotus dudkai KT031818 | 0 | 0.16 |
Dendronotus frondosus KM396976 | 6.71 | 6.55 |
Dendronotus venustus HM162709 | 8.11 | 7.96 |
Dendronotus kalikal KM396986 | 11.2 | 11.4 |
Dendronotus kamchaticus KM396989 | 11.86 | 11.7 |
Dendronotus albopunctatus GQ292064 | 12.01 | 11.86 |
Dendronotus niveus KM396996 | 12.32 | 12.17 |
Dendronotus dalli KM397001 | 13.88 | 13.73 |
Dendronotus lacteus KM396975 | 14.51 | 14.35 |
Dendronotus patricki HQ225828 | 14.7 | 14.5 |
Dendronotus robustus KM397002 | 14.8 | 14.7 |
Dendronotus regius HM162708 | 16.8 | 16.7 |
According to the morphological and molecular data presented above there are no species-level differences between D. primorjensis (Figs
Since D. frondosus is a closely related species to D. primorjensis (= D. dudkai syn. n.)(Fig.
Instead, it is suggested here that the number of denticles on the central teeth is a better diagnostic, and is higher in D. primorjensis (commonly more than 12, in holotype 14, reported range 12–18) than in D. frondosus (commonly up to 12, rarely up to 14 denticles in the topotype specimens from North Atlantic, pers. obs., reported range 8–12). The original description of the D. primorjensis is accompanied by two detailed SEM images of the radula (see
The number of lobules present in the prostate of D. dudkai are described by
Unfortunately, the description of D. dudkai contains a number of problems that prevent the repetition of their results obtained by molecular phylogenetic analysis. Despite the presence of a molecular analysis that was based on “additional material” (i.e. non-type specimens) no molecular data is available for the type material. According to their Table
The morphological and molecular data provided in this publication and two previous studies (Martynov et al. 2015 a, b) conclusively demonstrate that D. primorjensis is a valid species as per current ICZN regulations (
We are grateful to Vitaly Litvinenko and Andrey Maksimovsky (Dive Center Aquamax, Nakhodka city) for organizing the dives in Spokoinaya Bay, the Sea of Japan on 25 Sept 2014, and also to A.G. Bogdanov and G.N. Davidovich (Electron Microscopy Laboratory, Moscow State University) for support with electron microscopy. D.M. Schepetov is thanked for work with Genetic Analyser. Dendronotus dudkai was named in honour of Konstantin Dudka, a staff diver of the Institute of Marine Biology FEB RAS. We unreservedly apologize to Mr. Konstantin Dudka for any potential inconvenience or embarrassment. The study is supported by the Russian Science Foundation (grant 14-50-00029, SEM and molecular studies, depository of specimens), by Research project of MSU Zoological Museum (AAAA-A16-116021660077-3), and in 2013–2015 was supported by the Russian Foundation for Basic Research (grant 13-04-01641a), including an expedition grant during the course of which Dendronotus primorjensis type material had been collected.