Cognata Tellin Shell, Leporimetis cognata

Cognata Tellin Shell, Leporimetis cognata. Shell collected off the beach at Punta Chivato, Baja California Sur, February 2022. Size:  6.7 cm (2.6 inches) x 5.5 cm (2.2 inches) x 2.0 cm (0.8 inches). Collection, photograph and Identification courtesy of Colin Campbell, DVM, Punta Chivato, Baja California Sur.

Cognata Tellin Shell, Leporimetis cognata. Shell collected off the beach at Punta Chivato, Baja California Sur, February 2022. Size:  7.2 cm (2.8 inches) x 6.3 cm (2.5 inches) x 2.0 cm (0.8 inches). Collection, photograph and Identification courtesy of Colin Campbell, DVM, Punta Chivato, Baja California Sur.

Phylogeny: The Cognata Tellin, Leporimetis cognata (Pilsbry and Vanatta, 1902), is a bivalve mollusk that is a member of the Tellinidae Family of Tellin Clam Shells. The genus Leporimetis is one of one hundred four genera in this family, and there are ten species in this genus.

Description: Cognata Tellin shells are relatively large, but thin. They are subquadrate in shape and well inflated. The anterior is broadly rounded. The posterior slope has a flattened fold, giving the shell a twisted appearance. The exterior is marked with fine, concentric, lines, and is chalky white. The interior is white, and marked with fine pits. Cognata Tellin shells reach a maximum of 8.0 cm (3.1 inches) in length and 7.0 cm (2.8 inches) in height.

Habitat and Distribution: Cognata Tellins are found on sand and mud substrates, often in the area of rocks or boulders. They are found in the intertidal zone, and to depths up to 24 m (79 feet). They are a tropical Eastern Pacific species. In Mexican waters they range from Magdalena Bay, Baja California Sur to Guatemala. They are found throughout the Gulf of California.

Ecology and Behavior: Cognata Tellins are suspension feeders that feed primarily on plankton and suspended organic matter. They are gonochoric and reproduce sexually, through broadcast spawning, with external fertilization. There is no mention in the available literature of them engaging in any types of parasitic, commensal, or symbiotic relationships. From a conservation perspective they have not been formally evaluated however they are fairly common with a relatively wide distribution and should be consider to be of Least Concern.

Synonyms: Apolymetis clarki, Florimetis cognata, Lutricola cognata, Psammotreta (leporimetis) cognata, and Psammotreta cognata.