Shell slender, nearly four times as long as broad, with 10-12 whorls. Protoconch of four smooth whorls, often broken off. Teleoconch of 7-8 whorls with a sculpture of three spiral cords intersecting with axial folds to form a dense series of pearl-like knobs. Body whorl with one more spiral cord extending from the suture and a thickening adjacent to the columella. Aperture ovate, with a broadly open, very short but deeply incised siphonal canal.
whitish to yellowish, with the subsutural cord and the additional cord of the body whorl dark brown.
common size :
up to 4 x 1.1 mm.
This is, thanks to its color pattern, one of the most easily recognized species in this very difficult genus; there are about 25 native species of Cerithiopsis but all have uniformly brownish to nearly black shells.
BIOLOGY / ECOLOGY
All Cerithiopsis species live and graze on sponges, but the particular host of C. pulvis is not yet known.