Marine Animals

[WBANTA at auvm.american.edu]

Blue mussles on shores in California are limited at the upper part of the inter
tidal range largely by physical factors associated with tidal exposure: time to
 feed, dessication, etc.  On the lower end of the range they are limited more b
y predation, Pisaster (a starfish) being one main predator.  Littorina is a lar
ge genus of many species and vertical limits to its distribution are therefore
too complicated to discuss here.  Do you have a species in mind?  There is a
very large literature on this topic for all these species.