Most people, not only aficionados of the ocean, have had some experience with hermit crabs. Whether it was a family pet that eventually fertilized mother’s petunias or the ones sold at the shore in the summer, stricken with fluorescently spray-painted shells. However, if you are a little rusty on your "jointed-legged" friends, let me refresh your memory. Hermit crabs are crabs that carry shells on their backs wherever they go.
The term hermit conjures up all sorts of images from a holed up hobbit to a feisty old man. Well, these two images are not very far off from what one would describe a hermit crab to be. In fact hermit crabs never actually leave their homes, very similar to what one would describe a hermit to do. However, most people who are described as hermits, don’t carry their apartments on their backs.
["Hermit Crab" right]
Hermit crabs differ from true crabs in that the back section, known as the abdominal section, is not protected by a hard exoskeleton. To deal with this vulnerability hermit crabs have solved the problem by inhabiting the discarded shells of snails. With each molt hermit crabs outgrow the shells they inhabit. They search for an alternative shell that will accommodate their bodies and quickly move in. Hermit Crabs are notoriously obsessive about finding new shells. Even if the shell they currently inhabit is perfectly suited for them, they will often switch to a more pleasing shell they come across. This is understandable, as the shells become their permanent eveningwear everywhere they go.
The eyes of Hermit Crabs are at the tips of eye stalks. This unique feature enables hermit crabs to retreat to the interior of their shells when danger is near and to then slowly check out the status and safety of the situation by poking their eyes out first. Hmmmm, wouldn’t that be nice.
Another physical feature of hermit crabs is their uneven claw sizes. Often times one claw is much more enlarged than the other. Obviously the larger claw is more dominant than the other and therefore is used more often. We call this claw envy’, just kidding.
Hermit crabs are found in all different habitats worldwide. These habitats vary from tide pools to reef communities, to protected lagoons and sandy bottoms. Though they are occasionally difficult to spot during the day, they become extremely active at night. Scouring the bottom for scraps of food left over from the day. Maybe they should be called night-owl crabs.