Littorina obtusata

Littorina obtusata, common name the flat periwinkle, is a species of sea snail, a marine gastropod mollusk in the family Littorinidae, the winkles or periwinkles.

Distribution
This marine species occurs wherever brown seaweeds grow. It is widely distributed: the Baltic Sea, in European waters from Norway down to Southern Spain, in the Mediterranean Sea, in the Northeast Atlantic Ocean along the Gulf of Maine.

Description
The maximum recorded shell length is 13.5 mm.



Habitat
This species can be found in the littoral and sublittoral zone on rocky shores and piers, usually on brown algae of the genus Fucus. Minimum recorded depth is 0 m. Maximum recorded depth is 110 m. The habitat may define its color. On sheltered shores it has a lighter and uniform color (yellow, brown, orange or olive green). On exposed shores its color is darker and chequered.