Trochotaia Brandt, 1974

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 : 13

Trochotaia Brandt, 1974

Examined species: Trochotaia trochoides (Martens, 1860) ( Figs 4P , 5P , 7P ).

Remarks: Trochotaia can be distinguished from the other genera by a concentric inverted-comma-shaped operculum that exhibits the following combination of characters: a thick, rough layer with many grains or veins over the whole of the inner opercular region; a clearly convex outer margin; and a smooth enamel region with a dense ray-like pattern.

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.