The Littorinidae Family includes 224 species comprising 3 subfamilies (Littorininae (11 genus), Lacuninae (5), Laevilitorininae (2))
and 18 genus (Echinolittorina (62 species), Littoraria (38), Laevilitorina (24), Lacuna (24), Littorina (18), Tectarius (12), ...)

Phylum      : Mollusca
 Class       : ⤷Gastropoda 
  Subclass    : ⤷Caenogastropoda 
   Order       : ⤷Littorinimorpha 
    Superfamily : ⤷Littorinoidea 
     Family      : ⤷Littorinidae

Common name : periwinkles

Aspect : small, robust, spiral shells, conical or globular, with a pointed apex, often thick; size from a few millimeters to about 3 cm; white, brown, black, yellow or gray and may have spiral ridges, grooves, or color bands; tight-fitting operculum allowing them to wait dry for several days for the return of high tides; fine and sharp external lip

Feeding : herbivorous, grazing on microalgae, diatoms, and biofilm covering rocks or seaweed

Environment : common in temperate to tropical coastal regions worldwide; inhabit rocky shores, salt marshes, mangroves, and occasionally sandy or muddy substrates in intertidal and supratidal zones