In: Biology

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 third maixillipedes and fifth pereiopods for most grooming but used the unmodified first, second, and third pereiopods as well. MostRead More →

In: Biology

The mandible (from Latin: mandibula or mandĭbŭ-lum, a jaw) [1] of an arthropod is a pair of mouthparts used for either for biting, cutting and holding food. The last three cephalic segments, together with the three most anterior thoracic segments (all of the cephalothorax), house the external mouthparts. From anterior to posterior these are the mandibles, maxillules, maxillae and then the three pairs of thoracic maxillipeds. These are all biramous except for the mandibles and maxillules. [2] Mandibles are often simply referred to as jaws. Maxillipeds are appendages modified to function as mouthparts.  Hermit crabs are often seen grooming their eyes with their maxillipeds muchRead More →