California Spiny Jewel Box Shell, Arcinella californica

California Spiny Jewel Box Shell, Arcinella californica. Size: 5.0 cm (2.0 inches) x 4.8 cm (1.9 inches). Shell collected from within the estuary of the Magdalena Bay complex, Baja California Sur, October 2018.

Phylogeny: The California Spiny Jewel Box, Arcinella californica (Dall, 1903), is a bivalve mollusk that is a member of the Chamidae Family of Jewel Boxes. The genus Arcinella is one of six genera in this family, and there are four species in this genus.

Description: The California Spiny Jewel Box shell is somewhat cubical in shape, with an irregular outline. The exterior of the shell is adorned with elegant spines, some of which reach 6.0 cm (2.6 inches) in length. The shell is white in color. The California Spiny Jewel Box Shells reach a maximum of 7.4 cm (2.9 inches) in length and 7.1 cm (2.8 inches) in height.

Habitat and Distribution: California Spiny Jewel Boxes attach to solid substrate as juveniles and then become free living as adults. They are found over and within sand and fine rubble at depths between 11 m (35 feet) and 76 m (250 feet). They are a sub tropical to tropical Eastern Pacific species. In Mexican waters they range from Cedros Island, Baja California,  south to Guatemala. They are found throughout the Gulf of California.

Ecology and Behavior: California Spiny Jewel Boxes are suspension feeders that feed primarily on plankton and suspended organic matter.  They 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:  Echinochama arcinella and Echinochama californica.