Littorina obtusata. Image width ca. 3 cm.
Image: Sue Scott (published on the MarLIN Web site)
Littorina obtusata and Color Morphology
Ellen Machala
Biology Department, Clark University, Worcester, MA
Bio 201: Ecology of Atlantic Shores
Introduction
Natural History
Evaluation
Bio 201 Home
Abstract
The flat periwinkle, Littorina obtusata, appears to
camouflage itself in the fronds of the brown alga, Ascophyllum nodosum,
with various shell color morphologies. Data collected at Nahant, MA
shows a greater proportionate number of dark color morphologies upon dark
rock substrate with a greater proportion of yellow color morphologies upon
A. nodosum. Snail dimension measurements of the various
color morphs shows no significant variation in the height or length of the
different color morphs. Cryptic coloration may enable L. obtusata
to avoid visual predators, but further study is need to determine any role
of shell size in conjunction with shell color.
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