Byron Venus Clam Shell, Tivela byronensis

Byron Venus Clam, Tivela byronensis. Shell collected from within the estuary of the Magdalena Bay complex, Baja California Sur, October 2018.  Size: 4.4 cm (1.7 inches) x 4.1 cm (1.6 inches). Collection, photograph and identification courtesy of Bob Hillis, Ivins, Utah.

Byron Venus Clam, Tivela byronensis. Shell collected from within the estuary of the Magdalena Bay complex, Baja California Sur, October 2018. Size: 4.4 cm (1.7 inches) x 3.9 cm (1.5 inches). Identification courtesy of Bob Hillis, Ivins, Utah.

Phylogeny: The Byron Venus Clam, Tivela byronensis (J.E. Gray, 1838), is bivalve mollusk of the Veneridae Family of Venus Clams. The genus Tivela is one of one hundred and seven genera in this family, and there are twenty-eight species in this genus. They are known in Mexico  as Tivela de Byron.

Description: The Byron Venus Clam shell is a strong, inflated, sturdily-built shell that has a rounded triangle profile with a prominent beak. The exterior of the shell is sculpted with very fine concentric lines. The exterior is white to cream in color and may be marked by light, dark, or reddish- brown bands, chevrons, or spots; the interior is off-white, often with a purple wash. Some specimens have a blue or purple spot on the beak. They are covered with a light-brown thin, velvety periostracum. Byron Venus shells reach a maximum of 6.3 cm (2.5 inches) in length and 5.9 cm (2.3 inches) in height.

Habitat and Distribution: Byron Venus Clams reside in sand substrate. They are found intertidally, and at depths up to 73 m (240 feet). The majority of shells are collected as beach wash-ups. They are a subtropical to tropical Eastern Pacific species. In Mexican waters they range from Scammon’s Lagoon, Baja California to Guatemala, and they are found throughout the Sea of Cortez. Some sources state that this species is also found in the Western Atlantic but none site specific locations or collection data. Recent published observation data are limited to the Eastern Pacific.

Ecology and Behavior: Byron Venus Clams are suspension feeders, which feed on plankton and suspended organic matter. They are prey for fish, crabs, shore birds and gastropods. Byron Venus Clams are gonochoric and reproduce sexually, through broadcast spawning. 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: Cytheraea gracilior, Cytheraea hanleyana, Cytherea (Tivela) arguta, Cytherea hindsii, Cytherea pulla, Cytherea radiata, Cytherea semifulva, Tivela (Tivela) byronensis, Tivela elegans, Trigona byronensis, and Venus solangensis.