Frilled Venus Clam Shell, Chione undatella

Frilled Venus Clam Shell, Chione undatella. Shell collected from within the estuary of the Magdalena Bay complex, Baja California Sur, October 2018. Size: 4.0 cm (1.6 inches) x 3.6 cm (1.4 inches).  Identification courtesy of Bob Hillis, Ivins, Utah.

The Frilled Venus Clam, Chione undulata (G.B. Sowerby I, 1835), is a bivalve mollusk of the Veneridae Family of Venus Clams. They are also known as the Wavy Chione and in Mexico as almeja de costillas ondeadas, almeja ronosa del Mar de Cortez, and venus reñosa. The shell is thick with an oval shape. The exterior is marked with closely spaced concentric ridges. They have a short siphon and a well-developed foot. The exterior of the shell is white with brown blotches or broken, radiating, bands; the interior is white with purple near the posterior end. The Frilled Venus Shells reach 6.6 cm (2.6 inches) in length and 5.9 cm (2.3 inches) in height.

Frilled Venus Clams reside in shallow burrows within firm sand and sandy mud bottoms at depths up to 90 m (300 feet). They are found in bays and other places where they are protected from wave action and strong currents. They range from Southern California to Peru, including the Galapagos and Revillagigedo Islands and throughout the Sea of Cortez.

Synonyms include Venus entobapta, Venus excavate, Venus neglecta, Venus perdix, Venus simillima, and Venus undatella.