Shell pupoid, slender, conical, relatively solid, with a pointed apex, formed by six slightly convex whorls. Sculpture formed by both spiral grooves and axial ribs. The spiral sculpture is well marked between the axial ribs and attenuated over them. There is a more distinct groove near the suture, giving a beaded appearance to the adapical end of the ribs. A clear tooth on the columella. According to van Aartsen (1977), two teeth on the inside of the outer lip are sometimes present.
common size :
2- photo: J. J. van Aartsen
This species is distinguished from most native pyramidellids by its relatively large size, pupoid shape and type of sculpture. The most resembling among the native species is Chrysallida decussata (Montagu, 1803) which is much smaller and translucent, and has a very inconspicuous tooth. Other native species of Chrysallida usually lack the spiral on the adapical half of the whorls. Other immigrant species resembling this species are Chrysallida fischeri (Hornung and Mermod, 1925) and Turbonilla edgari (Melvil, 1869). With respect to the original description of C. decorata (Philippi, 1849), another name proposed for this immigrant form, van Aartsen (pers. comm.) considers that the immigrant has a clearly broader shell, a relatively bigger mouth, 20 axial ribs (instead of 14) - see photo 2 of van Aartsen; the columellar tooth is not mentioned in the description of Philippi who had assigned the species to the genus "Odontostomia" (= mouth with tooth, in latin).
BIOLOGY / ECOLOGY
Pyramidellidae are ectoparasites, mainly of sedentary polychaetes and molluscs.
live specimens from the intertidal zone; shells on beaches; dredged in 9-46 m depth. Southern Turkey: shells from detritus (9 m) at edge of Posidonia oceanica beds. Lebanon: 3m depth, on sandy bottom.