Sphaerium Scopoli 1777
Creators: name: Bespalaya, Yulia V.
name: Vinarski, Maxim V.
name: Aksenova, Olga V.
name: Babushkin, Evgeniy S.
name: Gofarov, Mikhail Yu.
name: Kondakov, Alexander V.
name: Konopleva, Ekaterina S.
name: Kropotin, Alexander V.
name: Mabrouki, Youness
name: Ovchankova, Nadezda B.
name: Palatov, Dmitry M.
name: Sokolova, Svetlana E.
name: Shevchenko, Alexander R.
name: Travina, Oksana V.
name: Taybi, Abdelkhaleq F.
name: Soboleva, Alena A.
name: Zubrii, Natalia A.
name: Bolotov, Ivan N.
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Bivalvia
Sphaeriida
Sphaeriidae
Sphaerium

description: Genus Sphaerium Scopoli, 1777
Type species: Tellina cornea Linnaeus, 1758.
Diagnosis: Shell large-sized (shell length in adults varies between 6 and 25 mm), rounded to ovate in shape, typically thick walled (Fig. 5E). The beaks rounded and slightly prominent or narrow, pore density varies among species (Fig. 5E, 6E). Cardinal and lateral
318 • Bespalaya et al.
teeth well developed (Fig. 6E). Nephridia moderately elongated. Two siphons (exhalant and inhalant) are present (Fig. 7E). The outer and inner demibranch relatively well developed.
Reproductive biology: The species of the genus are asynchronous brooders (they incubate their progeny in several separate brood sacs).
Distribution: Subglobal. This genus is known from Eurasia, Africa (Sphaerium stuhlmanni), North and South America (Sphaerium argentinum), East Africa, New Zealand (Sphaerium novaezealandiae), and Australia (Sphaerium tasmanicum) (Fig. 3A).
Sphaerium nitidum Clessin in Westerlund, 1876
(Fig. 8)
Sphaerium nitidum Westerlund, 1876: 97–104.
Type series: The lectotype [pair of valves, designated by Starobogatov in 1968] and eight paralectotypes are deposited in National Museum of Natural History, Stockholm, Sweden
(SMNH) nos 4725–4728 (see Fig. 8A). The lectotype was collected in Dudinka.
Type locality: Russia, Krasnoyarsk Territory, the Yenisei River near Dudinka (‘Jenissei, Dudino … (lat. 69°15 ʹ) … norr om Lusino … (lat. 68°40 ʹ); Westerlund, 1877: 67’).
Material examined: Russia: Vaygach Island, Talatinskoe Lake, VIII.2010, Aksenova, Bespalaya leg., five specimens (lot nos INEP-615, INEP-619); Yamal Peninsula, Seyaha River Basin, VIII.2014, Zubrii leg., 151 specimens (lot nos RMBH MSph-0011, MSph-0014, MSph-0015); Gydan Peninsula VII.2017, Sokolova & Shevchenko leg., 23 specimens (lot nos RMBH MSph 372), Yugorsky Peninsula VIII.2015, Spitsyn leg., two specimens (lot nos RMBH MSph-0087, MSph-0037), Krasnoyarsk Region, Taymyr Peninsula, Dudinka River, VII.2018, Aksenova, Sokolova, Shevchenko, Travina leg., three specimens (lot no. RMBH MSph-0415), Chukotka Peninsula, Amguema River Basin, VII.2019, Aksenova leg., four specimens (lot nos RMBH MSph-0494/2, MSph-0497/1).
Description: Shell medium sized (mean length ± SD 3.9 ± 1.1 mm, min–max 1.9–6.5 mm, N = 151), rectangular, with a characteristic concentric sculpture around the beaks (Fig. 8A–C). The beaks are rounded and slightly prominent. The cardinal tooth of the right valve is slightly curved, and the weaker split on the posterior end has divergent branches. The inner cardinal tooth of the left valve is thin, curved, and slightly S shaped (Fig. 8C). The outer cardinal tooth of the left valve is thin, slightly curved, and shorter than the inner cardinal tooth (Fig. 8C). The inner side of the valves is characterized by a high pore density. The nephridia are elongated (Fig. 8C, D).
Distribution: Kolguev Island, Vaygach Island, Yamal Peninsula, Gydan Peninsula, Yugorsky Peninsula, the Lower Yenisei Basin, Taymyr Peninsula, Chukotka Peninsula. According to some authors, S. nitidum was recorded in North America (Mackie et al.
1980, Mackie 2007). However, their records are not confirmed by genetic data.
Comments: The systematic position of S. nitidum has remained controversial to date (Korniushin 2001, Bespalaya et al. 2015a). The specimens studied by us correspond to the morphological and anatomical diagnosis given in the original description of S. nitidum (Fig. 8A; Westerlund 1876) and the re-description of this species published by Odhner (1921) (Fig. 8D). In addition, we obtained molecular-genetic data on S. nitidum from the Arctic region (Bespalaya et al. 2015a, 2022). The sequenced individuals from Vaygach, Yugorsky Peninsula, Yamal Peninsula, and Gydan Peninsula share the same 16S rRNA haplotype, which is identical to S. nitidum sequences from its type locality (Yenisei River, Dudinka Town, Krasnoyarsk Region) (Fig. 2), and is separated by three nucleotide substitutions from haplotypes of this species from Chukchi Peninsula and Kolguev Island (Bespalaya et al. 2022).
description: Published as part of Bespalaya, Yulia V., Vinarski, Maxim V., Aksenova, Olga V., Babushkin, Evgeniy S., Gofarov, Mikhail Yu., Kondakov, Alexander V., Konopleva, Ekaterina S., Kropotin, Alexander V., Mabrouki, Youness, Ovchankova, Nadezda B., Palatov, Dmitry M., Sokolova, Svetlana E., Shevchenko, Alexander R., Travina, Oksana V., Taybi, Abdelkhaleq F., Soboleva, Alena A., Zubrii, Natalia A. & Bolotov, Ivan N., 2024, Phylogeny, taxonomy, and biogeography of the Sphaeriinae (Bivalvia: Sphaeriidae), pp. 305-338 in Zoological Journal of the Linnean Society 201 (2) on pages 316-320, DOI: 10.1093/zoolinnean/zlad139, http://zenodo.org/record/13220074