Imbricate Cup-and-Saucer Shell, Crucibulum scutellatum

Imbricate Cup-and-Saucer Shell, Crucibulum scutellatum. Shell collected off the beach in the greater Cabo San Lucas area, Baja California Sur, January 2018. Size: 5.7 cm (2.2 inches) x 5.1 cm (2.0 inches).

Imbricate Cup-and-Saucer, Crucibulum scutellatum. Shell collected off the beach in the greater Cabo San Lucas area, Baja California Sur, March 2018. Size: 5.8 cm (2.3 inches) x 5.2 cm (2.0 inches).

 Phylogeny: The Imbricate Cup-and-Saucer Shell, Crucibulum scutellatum (Wood, 1828), is a gastropod mollusk that is a member of the Calyptraeidae Family of Cup-and-Saucer and Slipper Limpet Shell Family. The genus Crucibulum is one of eleven genera in this family, and there are nineteen species in this genus. They are also known as the Shield Cup and Saucer Shell and in Mexico as Picacho Corrugado.

Description: Imbricate Cup-and-Saucer Shells vary in outline of their base. They have coarse, scaly, radial ridges that extend to the shell margins as irregular scalloping. The interior cup is attached to the apex and usually attached on one side. The exterior of the shell is generally brown in color; the interior may be mottled gray and/or brown. Imbricate Cup-and-Saucer Shells reach a maximum of 7.7 cm (3.0 inches) in diameter.

Habitat and Distribution: Imbricate Cup-and-Saucer Shells are found on rocks and shells, on muddy substrates in the intertidal zone, and to depths up to 27 m (90 feet). They are a temperate to tropical Eastern Pacific species that are found in Mexican waters of the Pacific Ocean from Cedros Island, Baja California south to Guatemala. They are found throughout the Sea of Cortez.

Ecology and Behavior: Imbricate Cup-and-Saucer Shells are suspension feeders that feed primarily on plankton, which they capture with mucus nets created by their gills. 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: Calyptraea (Calypeopsis) rugosa, Calyptraea maculata, Calyptraea rugosa, Calyptraea trigonalis, Crucibulum corrugatum, Crucibulum imbricatum var. broderipii, and Patella scutellata.