The Grenadines are known for having nearly countless small underwater creatures to see under the sea. Arrow crabs, banded shrimp and other small creatures are plentiful to see if you are scuba diving.
We had seen a number of small hermit crabs during our trip to the Grenadines. There were quite a few to be seen, but for the most part they were in shells that were not much bigger than a silver dollar. Most species of hermit crab have long, spirally curved abdomens, which are soft, unlike the hard, calcified abdomens seen in related crustaceans. The vulnerable abdomen is protected from predators by a salvaged empty seashell carried by the hermit crab. The shell is ususally large enough so the crabs entire body can retract inside the shell. Hermit crabs often use the shells of sea snails (although the shells of bivalves and scaphopods and even hollow pieces of wood and stone are used by some species). The tip of the hermit crab’s abdomen is adapted to clasp strongly onto the columella of the snail shell. Most hermit crabs are nocturnal.
So I was not expecting to swim around a part of the reef only to come face to face with a hermit crab whose home shell was as big as my head.
Even assuming the crab did not fill the shell entirely, he was enormous, and obviously quite strong because he did not seem to have any problem trying to carry about such a large shell.