Tellin-like Sanguin Shell, Sanguinolaria tellinoides
Tellin-like Sanguin Shell, Sanguinolaria tellinoides. Size: 6.2 cm (2.4 inches) x 3.9 cm (1.5 inches). Shell collected from the beach in Los Barriles, Baja California Sur, February 2014. Collection, photograph, and identification courtesy of Bob Hillis, Ivins, Utah.
Phylogeny: The Tellin-like Sanguin Shell, Sanguinolaria tellinoides (A. Adams 1850), is a bivalve mollusk that is a member of the Psammobiidae Family of Sunset Clams. The genus Sanguinolaria is one of ten genera in this family, and there are six species in this genus. The genus name Sanguinolaria comes from the Latin word for blood and refers to the color of shells in this genus.
Description: Tellin-like Sanguin Shells are thin, to the point of being translucent, with an ovate outline. Both valves are equal in size and shape and are slightly inflated. The beak is low, the anterior of the shell is broadly rounded, and the posterior is narrower and elongated. The exterior is sculpted with very fine concentric ridges. The exterior of the shell is pink, rose, or purple in color, with some having white blotches. The interior is often a darker, reddish purple. The shell has a shiny finish, inside and out. Tellin-like Sanguin Shells reach a maximum 7.5 cm (3.0 inches) in length and 4.7 cm (1.9 inches) in height.
Habitat and Distribution: Tellin-like Sanguins live in sand in the intertidal zone, and to depths up to 12 m (40 feet). They are a subtropical to tropical Eastern Pacific species that are found in all Mexican waters of the Pacific Ocean with the exception that they are absent from north of Todos Santos, Baja California Sur, along the central and northwest coasts of the Baja Peninsula.
Ecology and Behavior: Tellin-like Sanguins are a poorly studied and understood species. There is very limited documentation of their diet, predation, reproduction or ecosystem interactions. Other species in the Psammobiidae Family are suspension feeders or deposit feeders, using their siphons to suck up plankton and detritus that drifts by or that is laying on the surface of the substrate. They are a facultatively mobile infaunal species and therefore able to move to food sources. They are gonochoric and reproduce sexually, through broadcast spawning, with external fertilization. Their engagement in any type of commensal, parasitic, or symbiotic relationships has not been formally documented. From a conservation perspective they 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: Sanguinolaria purpurea, Sanguinolaria tellinoides elongata, and Tellina miniate.