Home > Invertebrates > Bivalves > Lamarcka ventricosa

Updated 8/20/2025

Family Arcidae

INDO-PACIFIC / HAWAII

Lamarcka ventricosa

Kewalo Pipe, Oahu, 50 feet

 

Waimea Bay, Oahu, 30 feet

 

Byssus & scar, Lahilahi Cavern, Oahu, 60 feet

VENTRICOSE ARK

Common within cavities along ledges exposed to current deeper than 30 feet.  Attached by a tough byssus with the hinge facing out, they retract rapidly when disturbed.  The shell is usually heavily encrusted and eroded by coralline algae.  Attains 3.8 inches, 97 mm.  Red Sea to Hawaii and French Polynesia.  Formerly known as Arca ventricosa.