Other Basket Clam Shell, Caryocorbula otra

Other Basket Clam Shell, Caryocorbula otra. Shell collected off the beach at Punta Chivato, Baja California Sur, April 2025. Size: 2.5 cm (1.0 inches) x 1.6 cm (0.6 inches) x 0.6 cm (0.2 inches). Collection, photographs and Identification courtesy of Colin Campbell, DVM, Punta Chivato, Baja California Sur.

Phylogeny: The Other Basket Clam, Caryocorbula otra (Coan, 2002), is a bivalve mollusk in the Corbulidae Family of Basket Clam Shells. The Caryocorbula Genus is one of twelve genera in the Corbulidae Family and there are fourteen species in the Caryocorbula Genus. The genus name Caryocorbula is a combination of Greek and Latin words meaning something like “nut-like little basket”. This refers to the solid, nut-like, basket shape of these shells. The species name otra is Spanish for “other”. This name refers to this recently described species being “other than” previously described species. They are known in Mexico as Otra Almeja de Cesta or Corbula.

Description: Other Basket Clam Shells are ovate in outline and moderately inflated in profile. These shells are thick and solid. They are inequivalve, with the right valve slightly larger than the left. The posterior is longer than the anterior. The posterior end is set off by a rounded radial ridge. The posterior end is rostrate (beak-like) or tapered, often with a spout-like section. The anterior end is rounded. These shells are sculpted with rounded commarginal ribs. The exterior of these shells is generally whitish, with a pink or purple section in the center. The interior is also white, with varying amounts of pink or purple. Other Basket Clam Shells reach around 2.6 cm (1 inch) in length.

Habitat and Distribution: Other Basket Clams are found buried in sand or muddy  sand substrates, usually in protected waters. They live in the intertidal zone, and to depths of 55 m (180 feet). Other Basket Clam Shells are a subtropical to tropical Eastern Pacific species. The Other Basket Clam is found from Punta Chivato, Baja California Sur, to Guatemala. They are absent from the west coast of the Baja Peninsula.

Ecology and Behavior: Other Basket Clams are suspension feeders, which feed on plankton and suspended organic matter. They are preyed upon by shorebirds, crabs, fish, gastropods, and sea stars. Other Basket Clam Shells are gonochoric and reproduce sexually, through broadcast spawning with external fertilization. Their engagement in any type of commensal, parasitic, or symbiotic relationship has not been formally documented. From a conservation perspective Other Basket Clam Shells have not been formally evaluated. However, they are fairly common with a relatively wide distribution and should be considered to be of Least Concern.

Synonyms: Corbula otra.