Sinanodonta cf. gibba (Benson in Cantor, 1842 )

Kondakov, Alexander V., Palatov, Dmitry M., Rajabov, Zakir P., Gofarov, Mikhail Yu., Konopleva, Ekaterina S., Tomilova, Alena A., Vikhrev, Ilya V. & Bolotov, Ivan N., 2018, DNA analysis of a non-native lineage of Sinanodonta woodiana species complex (Bivalvia: Unionidae) from Middle Asia supports the Chinese origin of the European invaders, Zootaxa 4462 (4), pp. 511-522 : 513-516

Sinanodonta cf. gibba (Benson in Cantor, 1842)

Figs. 1–4 , Table 1

Anodon gibbum Cantor (1842) : 489.

Sinanodonta gibba Kraszewski and Zdanowski (2001) : 254; Izzatullaev and Boymurodov (2016): 17; Vinarski and Kantor (2016): 56.

Anodonta woodiana Sarkany-Kiss (1986) : 15; Watters (1997): 152 [partim]; Kraszewski and Zdanowski (2001): 253; Graf (2007): 86 [partim].

Sinanodonta woodiana Bogan et al. (2011) : 41 [partim]; Vinarski and Kantor (2016): 54 [partim]; Vikhrev et al. (2017): 1.

Sinanodonta orbicularis Izzatullaev and Boymurodov (2016) : 17; Vinarski and Kantor (2016): 56.

Sinanodonta puerorum Izzatullaev and Boymurodov (2016) : 17; Vinarski and Kantor (2016): 57.

Type locality: Chusan [Zhoushan] Island, China.

Material examined: Uzbekistan: Xorazm Region , near the town of Xonqa, a lake in the floodplain of the Amu Darya River, 41.53583° N, 60.88639° E, 23.vi.2017, 2 specimens [ RMBH: voucher nos. biv279_1 and biv279_2], Palatov leg.

Molecular data: Two identical COI sequences ( NCBI GenBank acc. nos. MG581711 and MG581712 , voucher nos. biv279_1 and biv279_2, respectively) were obtained.

Morphology: Shell elliptical, large and thick, rather inflated, slightly winged. Anterior margin rounded, posterior ridge truncated; ventral margin curved. Umbo elevated, in the first half of the shell. Periostracum brownyellowish with numbers of concentric striae. Nacre whitish, shining. Hinge edentulous. Muscle scars shallow. In our sample, shell length is 145–167 mm, height is 92–111 mm, and width is 58–64 mm (N = 2).

Habitats and ecology: A broad habitat and host generalist ( Watters 1997). In Middle Asia, the species inhabits plain rivers, canals, and ponds with clay-silty bottom; very common ( Izzatullaev and Boymurodov 2016).

Distribution: The species appears to be native for the Yangtze River system and adjacent islands of the East China Sea (e.g. Zhoushan Island) but is widely distributed in Europe, Middle Asia, East Siberia, Myanmar, and probably Turkey ( Table 1). In Uzbekistan, it was recorded in the Zarafshon River basin, a former tributary of the Amu Darya River, which is currently not reach the river because of agricultural water use, and in the Amu Darya and Syr Darya rivers ( Fig. 1 ).

Comments. Watters (1997) suggested that the maximum shell length of Sinanodonta woodiana sensu lato is 26 cm. Izzatullaev and Boymurodov (2016) noted that the shell length of Sinanodonta mussels in fish ponds of the Syr Darya River basin may reach a much larger size of up to 40–60 cm, and that a shell of 60 cm in length (Verigin leg.) is deposited in the collection of the Department of Ichthyology at Lomonosov Moscow State University. However, the largest shell in this collection is only 25 cm long (Dmitry M. Palatov, pers. comm., 2018) which fits with the known size range for this species.

Sinanodonta gibba appears to be the oldest available name for this species ( Table 1). This nominal taxon was described from the Zhoushan Island ( Cantor 1842), a part of the Zhoushan Archipelago, which is located in the Hangzhou Bay of the East China Sea, relatively close to the delta of the Yangtze River. This taxonomic hypothesis corresponds with an initial identification of the invasive Sinanodonta populations in Europe and Middle Asia by Ya. I. Starobogatov ( Kraszewski and Zdanowski 2001). Unfortunately, Starobogatov used the “comparatory approach” for identification of mussels (see Graf et al. 2007; Bolotov et al. 2013; Vinarski and Kantor 2016) and suggested two additional species in samples from Europe and Uzbekistan, i.e., Sinanodonta orbicularis and S. puerorum , likely due to the high variability of shell convexity ( Starobogatov and Izzatullaev 1984). Later, his identification was rejected because an isoenzyme analysis failed to confirm the hypothesis of three alien sympatric Sinanodonta taxa in Europe ( Kraszewski and Zdanowski 2001). The synonymy of numerous nominal taxa described from the Yangtze River basin, e.g., Sinanodonta harlandi (Baird & Adams, 1867) , S. orbicularis , S. puerorum , and S. qingyuani He & Zhuang, 2013 , is unclear and is in need of further detailed revision on the basis of an integrative taxonomic approach.

Figures

FIGURE 1. Distribution range of Sinanodonta cf. gibba (Benson in Cantor, 1842) in Uzbekistan. The red circle indicates our sequenced record from the Amu Darya River and the blue circles indicate published records (Appendix 2). The color hatching indicates the corresponding river drainage basins.

FIGURE 2. Habitat of Sinanodonta cf. gibba (Benson in Cantor, 1842) from Uzbekistan: a floodplain lake of the Amu Darya River near the town of Xonqa. (Photo: Alexey Chernyak).

FIGURE 3. Shell of a specimen of Sinanodonta cf. gibba (Benson in Cantor, 1842) from the Amu Darya River. Scale bar = 3 cm. (Photo: Ekaterina Konopleva).

FIGURE 4. Median-joining network of the COI sequences of Sinanodonta cf. gibba (Benson in Cantor, 1842) (N = 53; list of additional sequences in Appendix 1). The red numbers near branches indicate the numbers of nucleotide substitutions between haplotypes. Size of circles corresponds to the number of available sequences for each haplotype (smallest circle = 1 sequence).