Chemnitz’ Moon Shell, Notocochlis chemnitzii

Chemnitz’ Moon Shell, Notocochlis chemnitzii. Size: 2.5 cm (1.0 inch) x 2.4 cm (0.9 cm) x 2.0 cm (0.8 inches). Shell collected off the beach at Bahía Concepción, Baja California Sur, July 2008.  Collection, photograph and identification courtesy of Bob Hillis, Ivins, Utah.

Chemnitz’ Moon, Notocochlis chemnitzii. Shell collected off the beach at Punta Chivato, Baja California Sur, February 2022. Size: 2.5 cm (1.0 inch) x 2.1 cm (0.8 inches) x 2.0 cm (0.8 inches). Photograph and Identifications courtesy of Colin Campbell, DVM, Punta Chivato, Baja California Sur.

Phylogeny: The Chemnitz’ Moon Shell, Notocochlis chemnitzii (Pfeiffer, 1840), is a gastropod mollusk that is a member of the Naticidae Family of Moon Shells. The genus Notocochlis is one of thirty-eight genera in this species, and there are twelve species in this genus. They are known in Mexico as Nática Fanguera.

Description: Chemnitz’ Moon Shells are globular in shape and consist of about four to five whorls. They have a short spire, a pointed apex and an aperture that is large and semi-circular. The exterior of the shell is smooth and slightly polished. These shells have exteriors that are highly variable in color pattern with most being a bluish-gray or yellowish-gray, with darker bands or chevrons crossing the whorls.  Some have a cloudy appearance. The interior is brown with white bands and the operculum is white and calcareous. The Chemnitz’ Moon Shell reaches a maximum of 2.8 cm (1.1 inches) in length and 2.3 cm (0.9 inches) in height.

Habitat and Distribution: Chemnitz’ Moon Shells are the most abundant moon shell in the region. They are found on sand and mud substrates. They live in the intertidal zone, and to depths of up to only 3 m (10 feet). They are a tropical Eastern Pacific species. In Mexican waters they range from Magdalena Bay, Baja California Sur to Guatemala. They are also found throughout the Gulf of California.

Ecology and Behavior:  Chemnitz’ Moon Shells are predators that feed primarily on bivalves and gastropods, including other moon shells. They are gonochoric and reproduce sexually. They use their mantle to construct an “egg collar”- a wide ribbon of sand and mucous that forms a broken loop. The egg capsules are deposited on the inside surface of the loop. Then another layer of sand and mucous is placed over the eggs, sealing them inside. Once the eggs develop into larvae, they break out of the collar. The collar stays flexible, like thin plastic throughout the process. 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:  Natica chemnitzii, Natica pritchardi, and Natica undata.