Concameratum Cup-and-Saucer Shell, Crucibulum concameratum
Concameratum Cup-and-Saucer Shell, Crucibulum concameratum. Shell collected off the beach in the greater Cabo San Lucas area, Baja California Sur, March 2025. Size: 2.9 cm (1.2 inches) x 2.4 cm (1.0 inch) x 1.0 cm (0.4 inches). Identification courtesy of courtesy of Colin Campbell, DVM, Punta Chivato, Baja California Sur.
Concameratum Cup-and-Saucer Shell, Crucibulum concameratum. Shell collected off the beach of Punta Chivato, Baja California Sur, March 2025. Size: 3.3 cm (1.3 inches) x 3.2 cm (1.3 inches) x 0.9 cm (0.4 inches). Collection, photographs and identification courtesy of Colin Campbell, DVM, Punta Chivato.
Phylogeny: The Concameratum Cup-and-Saucer Shell, Crucibulum concameratum (Reeve, 1859), is a gastropod mollusk in the Calyptraeidae Family of Cup-and-Saucer Shells and Slipper Limpet Shells. The genus Crucibulum is one of eleven genera in this family, and there are nineteen species in this genus. In Mexico this species is called Picacho. The name concameratum comes from the Latin word for vaulted or arched.
Description: Concameratum Cup-and-Saucer Shells have an ovate outline and a fairly high volcano-like profile. The shell shape can be impacted by the shape of the substrate on which they grow. This shell is crisscrossed with both radial and concentric sculpting, which often forms pits in the shell’s exterior surface. The apex is off center, and slightly recurved. The exterior is white, with varying amounts of brown mottling. The interior cup is white and flattened on one side. Concameratum Cup-and-Saucer Shells reach a maximum length of around 3.0 cm (1.2 inches).
Habitat and Distribution: Concameratum Cup-and-Saucer Shells are found attached to rocks and other hard substrates within the intertidal zone at depths between 7 m (23 feet) and 90 m (295 feet). Concameratum Cup-and-Saucer Shells are a subtropical to tropical Eastern Pacific species that are found in Mexican waters of the Pacific Oceana from Bahía de los Ángeles, Baja California to Acapulco, Guerrero. They have not been documented from the west coast of the Baja Peninsula.
Ecology and Behavior: Concameratum Cup-and Saucer Shells are a poorly studied and understood species. There is very limited documentation of their diet, predation, reproduction or ecosystem interactions. Other species in Family Calyptraeidae are either suspension feeders that feed primarily on plankton, which they capture with mucus nets created by their gills, or depositional feeders that eat detritus. They are gonochoric and reproduce sexually. 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 considered to be of Least Concern.
Synonym: Crucibulum castellum