Nerita


Nerita is a genus of medium-sized to small sea snails with a gill and an operculum, marine gastropod molluscs in the family Neritidae, the nerites.
This is the type genus of the family Neritidae.

Distribution and habitat

Species of Nerita can be found worldwide in tropical waters in the middle and upper intertidal zones. They are gregarious herbivores.

Description

The thick shell is broadly ovate or globular and low-spired. It has a smooth surface. The shells are spirally ribbed or show some axial sculpturing. The ventral side has a large columellar callus or parietal wall. The callus shows small pustules. The aperture and the edge of the columella are usually dentate with fine or robust teeth. The calcareus operculum is thick and can be smooth or with a granular structure. The whorls are covered with strong spiral cords.

Taxonomy

Several subgenera have been proposed over the course of time, but various authors in the past could not agree on the placement of many species. The subgeneric placement of the species of Nerita was revised by Vermeij in 1984. However, inconsistencies still remain over the use and validity of many taxonomic names, because species show a wide variety of colors, patterns and even details of shell morphology, which has given rise to many synonyms.

Species

Species within the genus Nerita include:
; Subgenus Adenerita Dekker, 2000
; Subgenus Amphinerita von Martens, 1887
; Subgenus Argonerita Frey & Vermeij, 2008
; Subgenus Cymostyla von Martens, 1887
;Subgenus Heminerita von Martens, 1887
; Subgenus Ilynerita von Martens, 1887
; Subgenus Linnerita Vermeij, 1984
; Subgenus Lisanerita Krijnen, 2002
; Subgenus Nerita Linné, 1758
; Subgenus Ritena Gray, 1858: alternate representation of Nerita
; Subgenus Theliostyla Mörch, 1852

The Indo-Pacific Molluscan Database also includes the following species with names in current use
; Subgenus Amphinerita
;Subgenus Cymostyla von Martens in Kobelt, 1887
; Subgenus Heminerita Martens, 1887
; Subgenus Linnerita Vermeij, 1984
; Subgenus Melanerita Martens, 1889
;Subgenus Nerita Linnaeus, 1758
; Subgenus Ritena Gray, 1858
; Subgenus Theliostyla Mörch, 1852
;Species brought into synonymy: