Sunday, May 1, 2011

Hermit Crabs(:

by Sienna Purse
Latreille, 1802

Most species 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, into which its whole body can retract. Most frequently hermit crabs 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. As the hermit crab grows in size, it has to find a larger shell and abandon the previous one. This habit of living in a second hand shell gives rise to the popular name "hermit crab", by analogy to a hermit who lives alone. A few species do not use a "mobile home" and inhabit immobile structures left bypolychaete worms, vermetid gastropods, corals and sponges.

Form and Function:

Hermit crab species range in size, shape, from species with a carapace only a few millimetres long to Coenobita brevimanus which can approach the size of a coconut. The shell-less hermit crab Birgus Latro (coconut crab) is the world's largest terrestrial invertebrate.

The young develop in stages, with the first two (the nauplius and protozoea) occurring inside the egg. Most hermit crab larvae hatch at the third stage, the zoea. This is a larval stage wherein the crab has several long spines, a long narrow abdomen, and large fringed antennae. After several zoeal moults, this is followed by the final larval stage, the megalops stage.

Impact on Humanity:

Several marine species of hermit crabs are common in the marine aquarium trade. Of the approximately 15 terrestrial species in the world, the following are commonly kept as pets. These omnivorous or herbivorous species can be useful in the household aquarium as scavengers, because they eat algae and debris.
Journal Article Review:
"The unwanted guests of hermits: A global review of the diversity and natural history of hermit crab parasites"

This article is about the many parasites that a hermit crap can harbor in it's shell. There are about 130-140 species out of the 850 species of hermit crabs that are parasitized. This article goes on to talk about ways of parasitization and how we underestimate hermit crabs importance.

Works Cited:

McDermott, JJ, Williams, JD, & Boyko, CB. (2010). The unwanted guests of hermits: a global review of the diversity and natural history of hermit crab parasites.Journal of Experimental Marine Biology and Ecology,394. Retrieved from

Hermit crab anatomy. (n.d.). Retrieved from

Hermit crab lovers. (n.d.). Retrieved from

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