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Littorina
spp. (Periwinkles)
Copyright ©
2005 Mary Jo Adams
Two
species of periwinkles are commonly found in this area, Littorina
scutulata and Littorina sitkana. The best single word
to describe these periwinkles is "small". Littorina scutulata
grows to only about half an inch tall; its tapered shell is longer
than it is wide. This little periwinkle may be brown, blue-black
or even checkered.
Littorina
sitkana is the larger and chubbier of the two periwinkle species.
It still doesn't get very big, only about ¾ of an inch high
and the shell is almost as wide as it is high. The spire (the pointed
end of the shell) can also be described as "squat". Less
streamlined than L. scutulata, Littorina sitkana
prefers quieter waters. If you have sharp eyes, you may sometimes
find spiral sculpturing on the shell of Littorina sitkana.
Its color varies from brown or black to yellow or orange and it
sometimes has stripes. Both species live on rocks in the upper and
middle intertidal zones where they scoot along eating thin layers
of algae and try to avoid the 6-rayed sea star, Leptasterias
hexactis that preys on them.
This page was created by Mary Jo Adams on 10/29/05.
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