Shell fusiform, nearly three times as long as broad. Protoconch of four smooth whorls, often broken off. Teleoconch of six whorls with three spiral cords intersecting with axial folds to form a dense series of pearl-like knobs. Body whorl with two additional spirals. Aperture ovate, with a well-defined, very short but deeply incised siphonal canal.
uniformly dark brown, the protoconch paler.
common size :
2 x 0.7 mm.
This species is distinguished from most of the native Cerithiopsis species by its pupoid profile, and by having three rows of pearls from the very beginning of teleoconch whorls; whereas most species first have two rows and add a third one later on. It is distinguished from an undescribed native species by the protoconch whorls, which are smooth and form a tapering apex, whereas they are ribbed and cylindrical in the native species.
BIOLOGY / ECOLOGY
All Cerithiopsis species live and graze on sponges, but the particular host of C. tenthrenois is not yet known. The multispiral protoconch indicates planktotrophic larvae.