Anularya Zhang & Chen, 2015

Zhang, Le-Jia & von Rintelen, Thomas, 2021, The neglected operculum: a revision of the opercular characters in river snails (Caenogastropoda: Viviparidae), Journal of Molluscan Studies 87 (2), pp. 1-14 : 8

Anularya Zhang & Chen, 2015

Examined species: Anularya mansuyi (Dautzenberg & Fischer, 1905)

( Figs 4D , 5D , 7D );

A. bicostata (Tchang & Tsi, 1949) ( Figs 4E , 5E , 7E ).

Remarks: Except for the larger overall size and inner opercular region, the operculum of Anularya is most similar to that of Sinotaia . Apart from Sinotaia , Anularya can be distinguished from other genera with a concentric inverted-comma-shaped operculum by the following combination of characters: a thick, smooth, shiny, nontransparent and small nuclear region and a thick enamel region.

The operculum of A. mansuyi differs from that of A. bicostata by having a more acute opercular apex. The thickness of the adult operculum of A. mansuyi can vary from relatively thin to thick. Therefore, its colour can be transparent orange red to relatively nontransparent dark red.

Figures

Figure 4. Interior surface of opercula of the viviparid species studied. A. Celetaia persculpta. B. Ussuripaludina ussuriensis. C. Sinotaia angularis. D. Anularya mansuyi. E. Anularya bicostata. F. Torotaia mainitensis. G. Neothauma tanganyicense. H. Bellamya phthinotropis. I. Bellamya trochlearis. J. Idiopoma umbilicata. K. Idiopoma dissimilis. L. Filopaludina luzonica. M. Filopaludina martensi. N. Filopaludina bengalensis. O. Filopaludina gigantea. P. Trochotaia trochoides. ƍ. Taia naticoides. R. Taia shanensis. S. Notopala ampullaroides. T. Angulyagra cf. polyzonata. Scale bar: 5 mm.

Figure 5. Exterior surface of opercula of the viviparid species studied. A. Celetaia persculpta. B. Ussuripaludina ussuriensis. C. Sinotaia angularis. D. Anularya mansuyi. E. Anularya bicostata. F. Torotaia mainitensis. G. Neothauma tanganyicense. H. Bellamya phthinotropis. I. Bellamya trochlearis. J. Idiopoma umbilicata. K. Idiopoma dissimilis. L. Filopaludina luzonica. M. Filopaludina martensi. N. Filopaludina bengalensis. O. Filopaludina gigantea. P. Trochotaia trochoides. ƍ. Taia naticoides. R. Taia shanensis. S. Notopala ampullaroides. T. Angulyagra cf. polyzonata. Scale bar: 5 mm.

Figure 7. Shells of the viviparid species studied. A. Celetaia persculpta. B. Ussuripaludina ussuriensis. C. Sinotaia angularis. D. Anularya mansuyi. E. Anularya bicostata. F. Torotaia mainitensis. G. Neothauma tanganyicense. H. Bellamya phthinotropis. I. Bellamya trochlearis. J. Idiopoma umbilicata. K. Idiopoma dissimilis. L. Filopaludina luzonica. M. Filopaludina martensi. N. Filopaludina bengalensis. O. Filopaludina gigantea. P. Trochotaia trochoides. ƍ. Taia naticoides. R. Taia shanensis. S. Notopala ampullaroides. T. Angulyagra cf. polyzonata. Scale bar: 10 mm.