Elenae Moon Shell, Stigmaulax elenae

Elenae Moon Shell, Stigmaulax elenae. Shell courtesy of the commercial fishermen of the greater Los Cabos area, Baja California Sur, March 2010. Size: 5.8 cm (2.3 inches) x 4.5 cm (1.8 inches).

Elenae Moon Shell, Stigmaulax elenae. Shell collected off the beach of Punta Chivato, Baja California Sur, May 2023. Size:  3.0 cm (1.2 inches) x 3.1 cm (1.2 inches). Collection, identification and photographs courtesy of Colin Campbell, DVM, Punta Chivato.

Phylogeny: The Elenae Moon Shell, Stigmaulax elenae (Récluz, 1844), is a gastropod mollusk that is a member of the Naticidae Familly of Moon Shells. The genus Stigmaulax is one of thirty-eight genera in this family, and there are four species in this genus.  They are known in Mexico as Caracol Lunar Estriado and Caracol Luna de Elena.

Description: Elenae Moon Shells are stout, with four to five whorls, a blunt apex, and a deep umbilicus. The body whorl is very large. The aperture is large and semi-circular. The operculum is calcareous. The exterior of the shell is shiny and white to cream in color. They are marked with fine, often wavy, tan to reddish-brown lines running from the shoulder to the base. The interior has a purple blush. Elenae Moon Shells reach a maximum of 5.8 cm (2.3 inches) in length and 4.5 cm (1.8 inches) in width established by the shell photographed above.

Habitat and Distribution: Elenae Moon Shells are found on and within sand substrate, at depths between 3 m (10 feet) and 40 m (130 feet). They are a subtropical to tropical Eastern Pacific species that are found in all Mexican waters of the Pacific Ocean with the exception that they are absent from north of Magdalena Bay, Baja California Sur, along the central and northwest coasts of the Baja Peninsula and north of Puerta Chivata, Baja California Sur, in the Sea of Cortez.

Ecology and Behavior: Elenae Moon 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 Naticidae are predators that feed primarily on bivalves and other gastropods. They are gonochoric and reproduce sexually, with internal fertilization.  The eggs are laid in a “sand collar”. 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 elenae, Natica excavata, and Natica haneti.