Hermit Crabs

Mashes Sand Beach proved to be a good house hunting spot for this stripped hermit crab.

Mashes Sand Beach proved to be a good house hunting spot for this striped hermit crab.

Les Harrison is the UF/IFAS Wakulla County Extension Director

There are many species of the animal kingdom known to use tools. To humans, this is a sign of intelligence, at least to some degree.

While hermit crabs may not be considered a contender for the smartest animal on Earth, they are certainly capable of using tools to survive. Exactly when the first crustacean adapted to live in a shell is unknown, but the moment when that first arthro-pioneer laid eyes on an empty shell defined generations of a species.

Hermit crabs occupy thousands, if not millions, of once used marine gastropod shells in the shallow waters off the coast. The local species are members of the super family, Paguroidea.

This group is composed of approximately 1100 species worldwide; the striped hermit crab (Clibanarious Vittatus) being the most common species locally.

With no protective shell to shield them from predatory sea creatures, the hermit crabs commonly use the uninhabited shells of marine snails. If the shells of deceased gastropods are not available at the moment of need then other materials will be appropriated for immediate use.

In a pinch, any detritus with the necessary cavity and correct opening size will work.  This has even included wood scraps which have been artificially perforated or abandoned by marine worms.

These native crabs have a long and soft tail like abdomen which needs the protection of the adapted home.  This muscular appendage firmly grips its new surrounding as the basis of lifesaving armor.

If the hermit crab is lucky, it avoids becoming a snack for fish, stingrays, birds and terrestrial creatures which will quickly consume it. Its small size and relatively weak claws leave it with only the shell as a defense in a hostile world.

With time and good fortune, the hermit crab will grow and develop as it scavenges the beaches and shallow tidal pools. There comes a time when a new residence is necessary, and so the shell search starts.

Depending on the availability of empty shells, hermit crabs can be brutally competitive when in the relocation mode.

Hermit crabs are most commonly viewed on the beach as they maneuver awkwardly in their search for tidbits of nourishment. Even gentle surf will undermine their footing and spin them violently in the retreating wave.

Persistently and patiently, they will continue to emerge from the waves while lugging their latest abode above them. In Wakulla County waters, the hermit crabs may occupy shark’s eye snail shells, a variety of conchs, whelks or murex shells, periwinkles and many others.

Young beach goers have been amused for generations by the clumsy antics of these tiny crustaceans. Occasionally, they are smuggled home with the hopes of a novel pet, only to be discovered deceased a few days later. As cruel as it may seem, the hermit crabs endless search for a new home is done best in the shallow coastal waters.

To learn more about hermit crabs in Wakulla County, contact your UF/IFAS Wakulla Extension Office at 850-926-3931 or at http://blogs.ifas.ufl.edu/wakullaco/

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