Research Article |
Corresponding author: Xiongjun Liu ( 609449126@qq.com ) Corresponding author: Xiaoping Wu ( xpwu@ncu.edu.cn ) Academic editor: Graham Oliver
© 2021 Ruiwen Wu, Xiongjun Liu, Takaki Kondo, Shan Ouyang, Xiaoping Wu.
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:
Wu R, Liu X, Kondo T, Ouyang S, Wu X (2021) New species of the genus Inversidens Haas, 1911 (Unionoida, Unionidae, Gonideinae) from Jiangxi Province, China. ZooKeys 1054: 85-93. https://doi.org/10.3897/zookeys.1054.69075
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We diagnose and describe a new freshwater mussel species of the genus Inversidens, I. rentianensis sp. nov. from Jiangxi Province, China based on morphological characters and molecular data. This paper includes a morphological description and photograph of the holotype, and partial sequences of mitochondrial COI as DNA barcode data.
COI, freshwater mussel, genetic distances, morphology, taxonomy
The genus Inversidens Haas, 1911 belongs to the subfamily Gonideinae in the family Unionidae. The genus was first depicted by
Currently, only two species are recognized within Inversidens, the Japanese endemic I. brandtii and I. pantoensis in China (Fig.
In this study, we diagnose and describe a new Inversidens species from Jiangxi Province, China. In addition, we provide estimations of the intraspecific and interspecific genetic distances within Inversidens based on the mitochondrial COI barcode to examine species validity.
In March 2018, four samples were collected from the Mianshui River, Rentian Town, Ganzhou City, Jiangxi Province, China (25.989557°N, 116.131333°E). All type and voucher specimens are deposited at the Biological Museum of Nanchang University, China (NCFM180325-NCFM180328).
Of the four individuals, only two samples had tissues. Total genomic DNA was extracted from dissected somatic tissue using TIANamp Marine Animals DNA Kit (Tiangen Biotech, Beijing, China) according to the manufacturer’s instructions.
Mitochondrial cytochrome oxidase subunit I (COI) gene sequences have been widely used for species delimitation of freshwater mussels based on genetic distance and the criteria of monophyly (
We constructed a mitochondrial COI dataset with the newly obtained sequences from this study and the available Inversidens brandtii sequences from GenBank.
Previously published sequences were downloaded from GenBank and added to the dataset, i.e., 17 species of the subfamily Gonideinae and four species of the subfamily Unioninae for the ingroup, and one species of the subfamily Parreysiinae as the outgroup.
As a result, a total of 29 COI sequences were used for this study. Sequence details and GenBank accession numbers are shown in Table
Taxa | GenBank accession number |
---|---|
UNIONIDAE Rafinesque, 1820 | |
Parreysiinae Henderson, 1935 | |
Indonaia andersoniana (Nevill, 1877) | KX865835 |
Unioninae Rafinesque, 1820 | |
Acuticosta chinensis (Lea, 1868) | MG462919 |
Inversiunio jokohamensis (Ihering, 1893) | LC518985 |
Inversiunio reinianus (Kobelt, 1879) | LC518976 |
Nodularia douglasiae (Griffith & Pidgeon, 1833) | NC_026111 |
Gonideinae Ortmann, 1916 | |
Pseudodon bogani Bolotov, Kondakov & Konopleva in Bolotov et al. 2017 | MF352216 |
Pseudodon manueli Konopleva, Kondakov & Vikrev in Bolotov et al. 2017 | MF352228 |
Monodontina cambodjensis (Petit de la Saussaye, 1865) | KP795028 |
Pilsbryoconcha exilis (Lea, 1838) | KP795024 |
Chamberlainia hainesiana (Lea, 1856) | KX822635 |
Sinohyriopsis cumingii (Lea, 1852) | NC_011763 |
Sinohyriopsis schlegelii (Martens, 1861) | NC_015110 |
Lamprotula caveata (Heude, 1877) | KX822646 |
Lamprotula leaii (Griffith & Pidgeon, 1833) | NC_023346 |
Potomida littoralis (Cuvier, 1798) | JN243905 |
Pronodularia japanensis (Lea, 1859) | KX822659 |
Gonidea angulata (Lea, 1838) | DQ272371 |
Leguminaia wheatleyi (Lea, 1862) | KX822651 |
Microcondylaea bonellii (Férussac, 1827) | KX822652 |
Sinosolenaia carinata (Heude, 1877) | KX822669 |
Ptychorhynchus pfisteri (Heude, 1874) | KY067440 |
Parvasolenaia rivularis (Heude, 1877) | KX966393 |
Inversidens brandtii (Kobelt, 1879) | AB040827 |
Inversidens brandtii (Kobelt, 1879) | MT020598 |
Inversidens brandtii (Kobelt, 1879) | MT020597 |
Inversidens brandtii (Kobelt, 1879) | LC519005 |
Inversidens brandtii (Kobelt, 1879) | LC519004 |
Inversidens rentianensis sp. nov. 1* | MZ073336 |
Inversidens rentianensis sp. nov. 2* | MZ073337 |
All COI nucleotide sequences were translated to amino acid sequences using MEGA 5.0 (
Bayesian inference (BI) analyses were inferred in MrBayes Version 2.01 (
Holotype. China • Jiangxi Province, Ganzhou City, Rentian Town (壬田镇), Mianshui River (25.989557°N, 116.131333°E), 13 March 2018, coll. Xiongjun Liu (NCFM180325). Paratypes. Same data as holotype (NCFM180326-NCFM180328).
Inversidens rentianensis sp. nov. is morphologically distinct from the other two recognized species within the genus by shell shape, beak position and nacre colour (Table
Conchological characters of Inversidens rentianensis sp. nov., Inversidens brandtii, Inversidens pantoensis. Characteristic descriptions of I. brandtii and I. pantoensis are referenced from
I. rentianensis sp. nov. | I. brandtii | I. pantoensis | |
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Shell shape | Irregularly subtriangular | Ovate | Inequilateral, quadrate |
Umbo position | 1/2 of shell length | 1/4 of shell length | 1/3 of shell length |
Umbo sculpture | Feebly wavy wrinkles | Rippled | Angularly wrinkled |
Surface sculpture | Concentric ridges | Concentric ridges | Irregular growth lines |
Nacre colour | Reddish | Milk-white | Bluish |
Posterior slope | Sharp | Blunt | Blunt |
Ventral margin | Nearly straight | Arc-shaped | Long and straight |
Shell irregularly subtriangular, medium thickness, and quite inflated. Anterior margin regularly rounded; ventral margin nearly straight; posterior margin obliquely arc-shaped. Umbo prominent and slightly eroded. Umbo sculptured with feebly wavy wrinkles. Posterior slope formed by the ventral margin and posterior margin low, triangular. Epidermis shining black or with brownish-yellow hue. Only one cardinal tooth in each valve, shape triangular. Laterals thick, a little curved, 2 in each valve. Nacre reddish-bronze in colour.
Length 43–52 mm, height 29–36 mm.
The specific epithet is derived from the type locality, Rentian Town.
Pairwise COI sequence divergences from Inversidens brandtii and Inversidens rentianensis sp. nov. were conducted using MEGA 5.0. Based on the uncorrected p-distance model, the intraspecific divergences of I. brandtii and I. rentianensis sp. nov. were both 0.00%. The interspecific divergence of I. brandtii and I. rentianensis sp. nov. was 10.1%. Both BI and ML trees obtained a completely consistent topology. Consistent topology relationships are shown in Figure
Species delineation can be problematic in the presence of morphological ambiguities due to phenotypic plasticity and convergence (e.g., cryptic species), especially in mollusks (
We thank the reviewer Dr Manuel Lopes-Lima, the other anonymous reviewer and the Subject Editor Dr Graham Oliver for valuable comments that have greatly improved this manuscript. This work was supported by the National Natural Science Foundation of China under Grant No.31772412.