Littorina


Littorina is a genus of small sea snails, marine gastropod molluscs in the family Littorinidae, the winkles or periwinkles.
These small snails live in the tidal zone of rocky shores.

Overview

In Europe there are about nine species in this genus, one of which is the rough periwinkle, Littorina saxatilis. Another closely related species Littorina tenebrosa was thought to be distinct because of its different ecological requirements, but current studies have shown that it is not at all clear whether the two are indeed separate species or whether L. tenebrosa is perhaps merely an ecotype of L. saxatilis.
Littorina has given its name to the Littorina Sea, the geologic precursor of the Baltic Sea.

Distribution

The periwinkles are found on the seashore in the littoral zone and sublittoral zone in all parts of the world. In the Baltic they live within the influence of freshwater, and frequently become distorted in consequence.

Description

The thick, pointed shell is turbinated and has few whorls. The aperture is rounded. The outer lip is acute. The columella is rather flattened and imperforate. The operculum is paucispiral. The lingual teeth are hooked and trilobed. The uncini are hooked and dentated.

Species

The type species:Turbo littoreus Linnaeus, 1758 restricts the species in this genus to the northern hemisphere, moderate and cold zones. The tropical species belong in other genera of the same family
Species in the genus Littorina include Littorina aleutica Dall, 1872Littorina arcana Hannaford-Ellis, 1978Littorina brevicula Littorina compressa Jeffreys, 1865Littorina fabalis Littorina horikawai Matsubayashi & Habe in Habe, 1979Littorina islandica Reid, 1996 †Littorina kasatka Reid, Zaslavskaya & Sergievsky, 1991Littorina keenae Rosewater, 1978Littorina littorea, Common periwinkleLittorina mandshurica Littorina natica Reid, 1996Littorina obtusata, flat periwinkleLittorina petricola Arnold, 1908 †Littorina plena Gould, 1849Littorina remondii Gabb, 1866 †Littorina saxatilis, rough periwinkleLittorina scutulata Gould, 1849, checkered periwinkleLittorina sitkana Philippi, 1846Littorina sookensis Clark & Arnold, 1923 †
;Species brought into synonymy:Littorina aestuarii Jeffreys, 1865: synonym of Littorina obtusata Littorina affinis d'Orbigny, 1839: synonym of Tectarius striatus Littorina angulifera is a synonym for Littoraria angulifera Littorina arenica Jay, 1839: synonym of Tectarius striatus Litorina arenica Dunker, 1845: synonym of Tectarius striatus Littorina canariensis d'Orbigny, 1839: synonym of Tectarius striatus Littorina cingulifera R. W. Dunker, 1845: synonym of Littoraria cingulifera R. W. Dunker, 1845Litorina globosa Dunker, 1845: synonym of Tectarius striatus