Common Littleneck Clam Shell, Leukoma staminea
Common Littleneck Clam Shell, Leukoma staminea. Shell collected in the greater San Diego area, San Diego, California, July 2016. Size: 6.9 cm (2.7 inches) x 5.9 cm (2.3 inches). Collection, photograph and identification courtesy of Bob Hillis, Ivins, Utah.
Phylogeny: The Common Littleneck Clam, Leukoma staminea (Conrad, 1837), is a bivalve mollusk that is a member of the Veneridae Family of Venus Clam Shells. The genus Leukoma is one of one hundred seven genera in this family, and there are twenty-three species in this genus. They are known in Mexico as Almejuela Común.
Description: The Common Littleneck Clam is somewhat inflated, has an oval profile, and a moderate beak. The exterior of the shell is sculpted with numerous, fine, radiating ribs, and numerous, fine, concentric lines. They also have a few, heavy, concentric ridges. The margin is finely crenulated. The exterior of the shell is cream, tan or white in color, with brown specks or chevrons; the interior is cream colored. The Common Littleneck Clam shell reaches 8.0 cm (3.1 inches) in length and 6.8 cm (2.7 inches) in height.
Habitat and Distribution: Common Littlenecks are usually found over and within sand and mud substrate, in bays and other protected waters. They are also found in gravel, under loose rocks, along the open coastline. They live intertidally, and to depths up to 45 m (148 feet). They are a temperate Eastern Pacific species. They have a limited range in Mexican waters, ranging along the west coast of the Baja Peninsula from the northern border to at least Magdalena Bay, Baja California Sur. They are not found in the Gulf of California.
Ecology and Behavior: Common Littlenecks are suspension feeders that feed primarily on planktonic algae such as dinoflagellates, diatoms, and cyanobacteria. They are prey for crabs, starfishes, predatory snails, and octopuses. They are gonochoric and reproduce sexually, through broadcast spawning, with external fertilization. Common Littlenecks are known to host the bacterium Vibrio tapeti, which causes Brown Ring Disease. This species is edible and has been utilized as a food source for thousands of years, however, they can bioaccumulate toxins and cause Paralytic Shellfish Poisoning. 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: Chione ruderata, Paphia (Protothaca) staminea, Paphia (Protothaca) staminea var sulcosa, Paphia staminea, Paphia staminea orbella, Paphia staminea var sulcosa, Paphia grewingkii, Protothaca staminea, Tapes diversa, Tapes staminea, Tapes tumida, Venerupis petiti, Venus ampliata, Venus conradi, Venus mundulus, Venus pectunculoides, Venus rigida, and Venus stamina.