Land hermit crabs, also known as soldier crabs, or common land hermit
crabs, are fully terrestrial crabs that live in marine waters only during
the planktonic larval phase. Late-stage larval crabs emerge onto shorelines,
and burrow into
sands where they molt into juveniles. Choosing a
suitable snail shell to live in, they begin the process of establishing
themselves further and further inland. Adult female land hermits only return to
marine waters to release larvae during reproduction. Land hermit claws are
unequal, with the major claw rounded and bright purple in color. Eyes
are stalked. Body color is variable, ranging from reddish brown to
paler tones. Legs are tan-brown to red in color and are marked with
many purple dots and fine hairs. Carapace length may reach
approximately 1.5 inches (3.5 cm).
Land hermits occupy empty snail shells, with younger crabs preferring
nerite shells, and older crabs preferring those of whelks. These crabs
may be found in many terrestrial habitats, well inland of estuaries.
Land hermits scour the floors of scrub and inland forested habitats
consuming fruit, insects, carrion, feces and plant matter. There is
some evidence that selective grazing by land hermits influences the
development of terrestrial plant communities. Land hermit crabs can be
found wedged into fissures in trees, under exposed tree roots, in holes
under tree roots, or gathered in groups inside hollow stumps.
Land hermit crabs range from central Florida south throughout the
Caribbean. They are found in many habitats in the Indian River Lagoon.
Close-up view of the land hermit crab. Photo courtesy of K. Hill, SmithsonianMarine Station.
Evaporation is the most critical problem that land hermit crabs face.
In order to deal with this problem, land hermits store water in their shells
to prevent them from drying out, and for use in drinking.
They also "try on" many different shells, seeking ones that fit their
abdomens tightly to prevent water evaporation.