Thyca is a genus of small sea snails, marine gastropod mollusks in the family Eulimidae.Bouchet, P. (2012). Thyca H. Adams & A. Adams, 1854. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=196298 on 2012-07-25 These snails are ectoparasites of starfish; they are relatively unmodified, the underside having become a suction disc with a central mouth that draws nourishment from the host's tissues.
Description The conical shell is longitudinally grooved, transparent and slightly curved.G.W. Tryon (1886) Manual of Conchology v; VIII
Species Species within the genus Thyca include: Thyca astericola (A. Adams & Reeve, 1850) Thyca callista Berry, 1959 Thyca crystallina (Gould, 1846) Thyca ectoconcha P. Sarasin & F. Sarasin, 1887 Thyca hawaiiensis Warén, 1980 Thyca lactea (Kuroda, 1949) Thyca nardoafrianti (Habe, 1976) Thyca sagamiensis (Kuroda & Habe, 1971) Thyca stellasteris Koehler & Vaney, 1912 Species brought into synonymy Thyca pellucida Kükenthal, 1897: synonym of Thyca crystallina (Gould, 1846)
References
Habe T. (1976) Parasitic gastropods from echinoderms of Japan. Bulletin of the National Science Museum [Tokyo], ser. A, 2(3): 157-171. [22 September 1976] page(s): 165 Warén A. (1980). Revision of the genera Thyca, Stilifer, Scalenostoma, Mucronalia and Echineulima (Mollusca, Prosobranchia, Eulimidae). Zoologica Scripta 9: 187-210 Warén A. (1984) A generic revision of the family Eulimidae (Gastropoda, Prosobranchia). Journal of Molluscan Studies suppl. 13: 1-96. page(s): 46