Stilifer linckiae Sarasin and Sarasin, 1887. Length, 6 mm; diameter, 3 mm. Shell: ovate; whorls convex; thin, fragile, chalky white. Spire: five whorls plus the mucronate apex; whorls convex, abutting. Sculpture: microscopic growth striae only. Aperture: subcircular. Color: white. Animal: pseudopallium large, covering most of the shell.
S. linckiae is an endoparasite in the starfish Linckia multifora. The snails are found in enlarged areas or "galls," usually on the outer part or the lateral ventral side of the rays. The galls occupy a position within the body wall but are separated from the coelomic cavity by a layer of connective tissue, and open to the exterior by way of a small pore through which the egg masses are extruded (Davis, 1967; Tullis, 1968). One to five snails are found in a single gall (Davis, 1967), one usually much larger than the others. Each snail within a gall is independent and has its own aperture to the exterior (Lutzen, 1972). These gastropods appear to be consecutive hermaphrodites. Tullis (1968) reports testes and different developmental stages of sperm are present in small snails but only mature eggs occur in large snails. Lutzen (1972) suggests the young function as males, older individuals as females. The eggs are deposited on the substratum and veligers are released within four to eight days after deposition (Tullis, 1968). The tendency for spontaneous autotomy, the separation of one or more arms from the central disk, normally fairly high in starfish, is considerably reduced in parasitized rays, and this reduction may be associated with the parasite (Davis, 1967).
S. linckiae and its host were described from Ceylon.