Sinotaia quadrata histrica (Gould, 1859)

Saito, Takumi & Kagawa, Osamu, 2020, New insights from museum specimens: a case of Viviparidae (Caenogastropoda: Mollusca) in Iwakawa's collection preserved in the National Museum of Nature and Science, Tokyo, Biodiversity Data Journal 8, pp. 52233-52233 : 52233

Sinotaia quadrata histrica (Gould, 1859)

Paludina histrica Gould 1859: 41. Type locality: Ousima and Loo Choo [Amami-Oshima and the Ryukyu Islands]. (original description).

Paludina nitens [?] Paludina nitens Reeve 1863: pl. 10, fig. 59. Type locality: Japan. (original description).

Paludina ingallsiana - Iwakawa 1897a: 86, pl. 5, figs. 5-6 [part]; Iwakawa 1897b: 5, pl. 2, fig. 6 [part].

Viviparus histricus - Pilsbry 1902: pl. 9, fig. 5.

Vivipara histrica - Kobelt 1909: 107, pl. 16, fig. 6.

Vivipara nitens [?] Vivipara nitens - Kobelt 1909: 107.

Vivipara lacustris [?] Vivipara lacustris - Kawamura 1918: 358.

Viviparus quadratus var.? histricus - Hirase 1927: 1382, fig. 2656.

Cipangopaludina histrica - Kuroda 1928: 32.

Viviparus (Viviparus) histricus - Prashad 1928: 172.

Viviparus histricus - Iwakawa 1919: 72.

Viviparus (Sinotaia) histricus - Hirase and Kuroda 1947b: 1160, fig. 3301.

Taia (Sinotaia) histrica - Kuroda 1947b: 4.

Sinotaia histrica - Kuroda 1948: 26.

Viviparus (Idiopoma) histricus - Okada and Kurasawa 1950: 149, figs. 3-4, 12-14 (in text), pl. 1, figs. 1-2, pl. 3, figs. a'-g'.

Sinotaia quadratus histrica - Kuroda and Habe 1965b: 48, fig. 152.

Sinotaia quadrata histrica - Habe and Kosuge 1967: 27, pl. 11, fig. 8.

Materials

Type status: Other material. Occurrence: occurrenceDetails: https://www.gbif.org/occurrence/2864965306; catalogNumber: 2960H ex.NSMT-Mo 2960 ; recordNumber: 2960 in Iwakawa 1919; individualCount: 1; lifeStage: adult; preparations: shell (dried); previousIdentifications: Viviparussclateri (Frauenfeld, 1865) in Tomotaro Iwakakawa. 1919. Catalogue of Japanese Mollusca in the Natural history department, Tokyo Imperial Museum, the tokyo Imperial Museum, Tokyo, Japan, p. 72.; occurrenceID: paper:SK2020:2960H; Taxon: scientificName: Sinotaiaquadratahistrica (Gould, 1859); kingdom: Animalia; phylum: Mollusca; family: Viviparidae; vernacularName: Hime-tanishi (in Japanese name); Location: country: Japan; stateProvince: Nagano; locality: Lake Suwa ; verbatimLocality: Suwako (in Japanese) [Lake Suwa]; Identification: identifiedBy: Takumi Saito; dateIdentified: 2020-02-03/04; Event: year: before 1919; Record Level: language: Japanese; bibliographicCitation: Tomotaro Iwakakawa. 1919. Catalogue of Japanese Mollusca in the Natural history department, Tokyo Imperial Museum, the tokyo Imperial Museum, Tokyo, Japan, p. 72.; institutionCode: NSMT; collectionCode: Mo; basisOfRecord: PreservedSpecimen Type status: Other material. Occurrence: occurrenceDetails: https://www.gbif.org/occurrence/2864965308; catalogNumber: 2961H ex.NSMT-Mo 2961 ; recordNumber: 2961 in Iwakawa 1919; individualCount: 5; lifeStage: adults; preparations: shell (dried); previousIdentifications: Viviparussclateri (Frauenfeld, 1865) in Tomotaro Iwakakawa. 1919. Catalogue of Japanese Mollusca in the Natural history department, Tokyo Imperial Museum, the tokyo Imperial Museum, Tokyo, Japan, p. 72.; occurrenceID: paper:SK2020:2961H; Taxon: scientificName: Sinotaiaquadratahistrica (Gould, 1859); kingdom: Animalia; phylum: Mollusca; family: Viviparidae; vernacularName: Hime-tanishi (in Japanese name); Location: country: Japan; stateProvince: Nagano; locality: Lake Suwa ; verbatimLocality: Suwako (in Japanese) [Lake Suwa]; Identification: identifiedBy: Takumi Saito; dateIdentified: 2020-02-03/04; Event: year: before 1919; Record Level: language: Japanese; bibliographicCitation: Tomotaro Iwakakawa. 1919. Catalogue of Japanese Mollusca in the Natural history department, Tokyo Imperial Museum, the tokyo Imperial Museum, Tokyo, Japan, p. 72.; institutionCode: NSMT; collectionCode: Mo; basisOfRecord: PreservedSpecimen

Diagnosis

Adult shell small and thin, but not fragile; shell shape subconical to pyramidal. Adult shell bright brown or yellowish- or reddish-brown often covered with many attachments such as alga; shell surface slightly glossy, weak growth lines and spiral lines are usually present. Suture shallow; spire rounded. Young shell small, very thin and fragile; shell shape pyramidal with rounded angle. Young shell bright olive; shell surface quite glossy with no spiral ridges on upper part of the spire.

Taxon discussion

Sinotaia quadara histrica can be distinguished from other Japanese Viviparidae by the following features, based on the illustrations and information from literature (Suppl. material 1). In particular, the adult shell width tends to be relatively smaller than that of other Japanese Viviparidae ( Masuda and Uchiyama 2004; for example, under 24 mm except for one exception in Kagawa et al. (2019)).

Firstly, S. q. histrica is easily distinguished from Cipangopaludina species/subspecies in Japan, based on the small shell width, pyramidal shell shape and the higher spire (Fig. 5 ).

The size of Heterogen sp. is larger and the apical whorls are also larger than those of S. q. histrica . In addition, Heterogen sp. has the weak spiral ridges on even the early whorls, whereas S. q. histrica does not have them. Diagnostic differences between S. q. histrica vs. H. japonica and H. longispira have been provided above, so we refer to the taxon discussions of these latter two species.

Notes

Sinotaia quadara histrica was identified in two of the 11 lots examined, which were from Lake Suwa (Fig. 5 ). Some specimens of H. japonica from Lake Suwa have a similar shell shape to S. q. histrica , but S. q. histrica has a more rounded shell apex, a broader spire angle, shallower sutures and a brighter colour than those of H. japonica .

We treated only the Japanese Sinotaia species for synonymy, as the taxonomic relationship between the continental Sinotaia and the Japanese Sinotaia species is not clear and not the point of this study. The species-group name, nitens was synonymised with a question mark by Pilsbry (1902) and we followed this treatment. Vivipara lacustris in Kawamura (1918) was documented as a small species that is distributed in the Kyushu Region. In the past, S. q. histrica was considered to be distributed in Kyushu Region ( Pilsbry 1902) and so V. lacustris in Kawamura 1918 may be a junior synonym of S. q. histrica .

Figures

Figure 5. Representative shells of Sinotaia quadrata histrica (Gould, 1859) from Japan, deposited in the collection of the National Museum of Nature and Science, Tokyo, which were treated as Viviparus sclateri (Frauenfeld, 1865) in Iwakawa (1919). a-c: Lake Suwa, Nagano Pref. (a: 2960 H, b-c: 2961 H).