Funiculate Nerite Shell, Nerita funiculata

Funiculate Nerite Shell, Nerita funiculata. Shell collected off the beach of Bahía Concepción, Baja California Sur, October 2019. Size: 1.5 cm (0.6 inches) x 1.1 cm (0.4 inches). Identification courtesy of Bob Hillis, Ivins, Utah.

Phylogeny: The Funiculate Nerite Shell, Nerita funiculata (Menke, 1851), is a gastropod mollusk that is a member of the Neritidae Family of Nerite Shells. The genus Nerita is one of thirteen genera in this family, and there are seventy-four species in this genus.

Description: The Funiculate Nerite Shell is composed of three whorls, with a very low, flat-topped spire. The body whorl makes up the great majority of the shell. The exterior of the shell is sculpted with rounded, narrow, ridges, which follow along the whorls, and close ribs running the length of the shell. They have a large D-shaped aperture that is sculpted with folds and pustules. The exterior of the shell is a pattern of black and white lines and speckles. The interior is white. The Funiculate Nerite Shells reach a maximum of 2.5 cm (1.0 inch) in length and 1.8 cm (0.7 inches) in height.

Habitat and Distribution: Funiculate Nerites are found attached to, and under, rocks. They live in the intertidal zone, and to depths up to 5 m (15 feet). They are a subtropical to tropical Eastern Pacific species. In Mexican waters they are found throughout the Gulf of California, and range south to Guatemala. They are not documented from the west coast of the Baja Peninsula.

Ecology and Behavior: Funiculate Nerite Shells are herbivorous grazers that  feed on algae, including filamentous algae, cyanobacteria, diatoms, and film algae.  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. Funiculate Nerite Shells are sometimes harvested by the aquarium trade. 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: Nerita (Theliostyla) funiculata, Nerita bernhardi, Nerita cerostoma, Nerita excavata, Nerita genuana, Nerita granulata, and Nerita regalis.