However, some crabs will forage at shallower depths and in the intertidal zone, where food is more abundant. Due to the increased growth rate of crabs who forage at shallow depths and the higher survivorship of crabs who forage in deep water, both behaviors have a roughly equivalent effect on fitness.
While some crabs prefer shallow waters with plentiful food sources, others thrive in deeper areas.  Both foraging strategies result in comparable fitness benefits, as the faster growth of shallow-water crabs and the greater survival rate of deep-water crabs contribute to similar overall fitness levels.