walking

In hermit crabs, the fourth and particularly the fifth pereopods are reduced, usually remaining within the confines of the gastropod shell and hence are not used for walking. These appendages do however becoming important when the hermit crab attempts to right itself, providing anchorage within the shell. Further, the fifth pereopod has become specialised as a gill cleaning appendage, often resting within the gill chamber (Bauer 1981). On the abdomen only the left pleopods are retained (Poore 2004).[1] Hermit crabs used specialized setae on the their maixillipedes and fifth pereiopods for most grooming but used the unmodified first, second, and third periopods as well. MostRead More →