Home > Invertebrates > Shells > Rissoidae > Zebina bidentata

Created 4/5/2026

Family Zebinidae

INDO-WEST PACIFIC / HAWAII

Zebina bidentata

 Waianae, Oahu, 70 feet, 4mm

 

TWO-TOOTHED RISSO

Occurs in sand under stones or rubble at any depth.  Glassy and tapering, suture slightly impressed, whorls slightly convex with microscopic axial striae, often two or three denticles on the lower outer lip.  Denticle development is dependent on maturity of the outer lip.  Attains 0.2 inch, 4mm.  Mauritius, Philippines, and Hawaii, to French Polynesia.  Formerly known as Zebina semiplicata.