Four-tooth Nerite Shell, Nerita versicolor

Four-tooth Nerite Shell, Nerita versicolor. Underwater photograph taken in coastal waters off Cozumel Island, Quintana Roo, March 2021. Photograph and identification courtesy of Marina Sutormina, Stockholm, Sweden.

The Four-tooth Nerite, Nerita versicolor (Gmelin, 1791), is a gastropod mollusk that is a  member of the Neritidae Family of Nerites. They are also known as the Four-toothed Nerite and the Variegated Nerite.

The Four-tooth Nerite Shell is thick, heavy and rounded globose with a large body whorl with groves that follow the shell’s spiral. Most are slightly wider than tall with a short spire and four thick rounded spiraling ribs. They are off white in color with black and a wide variety of different colors and patterns. Most shells have black and red dots and bars in straight or zigzag patterns. Their outer lip normally has black, red, and white pigmentation. Their columella is lunate with a straight edge and the aperture is wide and thick with yellow tinges and the inner lip has four large teeth for which they are named. Their operculum is rounded, stiff, brittle, curves inward, and is covered with small fine bumps the thickness of a fingernail and gray-brown in color. The Four-tooth Nerite reaches a maximum of 22.1 cm (8.7 inches) in length. The majority are approximately 2.54 cm (1.0 inch) in height and 2.54 cm (1.0 inch) in width. The snail has a snout body with a short blunt head and is dark gray to black in color with pale gray-white undersides.

The Four-tooth Nerite are benthic, found on the ocean’s bottom in the intertidal zone being mobile and follow the high tide water level. They have the ability to withstand periods of heat and desiccation. They are grazers and detritivores, utilizing long major tentacles that extend outwards on either side of the head. Reproduction involves two sexes.

The Four-tooth Nerite is a resident of all Mexican waters of the Atlantic Ocean, including the Gulf of Mexico and the east coast of the Yucatán Peninsula in the Caribbean.

The Four-tooth Nerite is similar to the Bloody Tooth Nerite, Nerita peloronta (lacks the four distinct teeth and is rust-red in color).

The Four-tooth Nerite is common with stable and widely-distributed populations. They have been documented to 2.6 million years ago. They are popular with the aquarium trade being easy to maintain.