The animal on the cover of Programming .NET Components, Second Edition, is a
land hermit crab (Coenobita clypeatus). Land hermit crabs are found in tropical areas
of the Indo-region, the western Atlantic, and the western Caribbean. They live close
to the shoreline and must have access to land and water.
The front half of a hermit crab is covered with a hard exoskeleton. The long
abdomen has a softer exoskeleton that can adjust to fit into a spiraled shell. The large
left claw is used for defense, for holding onto tree limbs, and for balance. The smaller
right claw and the next pair of appendages are used for collecting and passing food
and water to the mouth. Hermit crabs have stalked eyes with acute vision and two
pairs of antennae. The longer pair of antennae is used for feeling, the shorter for
smelling and tasting.
The land hermit crab doesn’t have a hard shell of its own; it uses old empty shells to
protect its soft body. As it grows in size, the hermit crab must find a larger shell.
When danger threatens, it hides in the shell and closes the entrance with its hard
claw. Hermit crabs are omnivores and scavengers. They eat worms, plankton, and
Although land-based, these crabs must return to the sea to breed. Both males and
females partially emerge from their shells to mate. The female lays her hundreds of
eggs inside the borrowed shell. These eggs are safe and damp in the shell but, when
they hatch, they must be released in the sea. The young are in danger until they find
a shell of their own. When they reach adulthood, the crabs migrate to begin their
terrestrial life. Land hermit crabs live about 10 years.