HERMIT CRABS
Among the most popular and favorite invertebrate animals that we find on Tybee’s beach are
Hermit Crabs. They are fun to find and watch. They are small, harmless, and easy to catch, so
they are good for all ages of beach explorers. In a touch tank or tide pool, they are active and
interact with each other, so they are fun to watch. And our Tybee Hermit Crabs occupy all kinds
and colors of shells, so with even just a few individuals, it’s like having a variety of animals.
Our native Hermit Crabs live under water and are not adapted to living on land like the land
hermit crabs that you see in stores. The best place to find them on Tybee is in tide pools on the
beach or around the jetties. Sometimes you might find one lying on the wet sand while the tide
is out. I’ll think I’m finding a nice Whelk or Moon Snail shell, only to find out that a Hermit Crab
has already found it!
Usually all we get to see is the front half of a Hermit Crab – its head, legs and claws. The rest of
its body, its rear end, is soft and mushy. So the Hermit Crab finds something, usually a snail shell,
to stick its rear end into for protection of that soft part of its body. That works well for awhile, but
as the Hermit Crab grows and its rear end gets bigger, it needs a larger shell. So it is common to
see Hermit Crabs messing with each other, checking out each others’ shells, and often fighting
with each other, trying to pull somebody out of its shell so it can move into it.
On Tybee we have three different species of Hermit Crabs. The most abundant is the Longwristed
Hermit Crab. These are the small ones with long, skinny white legs and claws. It is not
uncommon to find dozens of them in a tide pool. They are active, fast-moving little guys that use
all kinds and colors of snail shells for protection. Occasionally we find Striped Hermit Crabs. They
tend to be larger and have orange and brown striped legs and claws. Because they are larger,
they are usually in nice medium-to-large Moon Snail shells and small Whelk shells. Our third
species is the Flat-clawed Hermit Crab. They have large mitten-like claws that are shaped just
right so that when the Hermit Crab withdraws into its shell, this pair of flat claws make a nice
“trap door” inside the opening of the shell. They are usually in Moon Snail shells, and their flat
claws perfectly fit the shell’s opening. When we have them in a beach touch tank, they seem to
be a bit shy and not as active as the little Long-wristed guys.
When you find some Hermit Crabs on Tybee, take a few minutes to let them entertain you. They
can handle being out of the water for a little while, so it’s fine to let them tickle your hand as they
walk around on it, but they need to be returned to the water frequently.
Dr. Joe Richardson (Ph.D. Marine Sciences) is a retired marine science professor with 40 years
of research and teaching experience along GA, the southeastern coast and Bahamas. Besides
research, he conducts Tybee Beach Ecology Trips (www.TybeeBeachEcology.com) and frequently
posts pictures of their findings on his Tybee Beach Ecology Trips Facebooks page.
Beach Walks
with Dr. Joe
By Dr. Joe Richardson
20 TYBEE BEACHCOMBER | AUG 2018
/(www.TybeeBeachEcology.com)