ABSTRACT
The terrestrial environment, with a unique set of fouling parameters, has been invaded by certain amphipod, isopod, and decapod species. In an effort to characterize grooming in these crustaceans, behavior of representative organisms was recorded, and grooming appendages were examined with light and scanning electron microscopy. The mouthparts and gnathopods, particularly the scale-bearing second pair, were the primary amphipod grooming appendages. Isopods most frequently used the mouthparts and first pereiopods for grooming, but all pereiopods performed some acts. The mouthparts were armed with both scales and setae, whereas the first pereiopods made use of a seta-lined carpal groove and the setose proximal propodus. Hermit crabs used specialized setae on the third maxillipedes and fifth pereiopods for most grooming but used the unmodified first, second, and third pereiopods as well. Most brachyuran grooming was performed with modified setae on the third maxillipedal palps and epipods, with a row of simple setae on each chelipede merus, and with the chelipede fingers. The unspecialized walking legs rubbed each other. Terrestrial, ‘semiterrestriar, and aquatic amphipods of the superfamily Talitroidea have basically similar grooming behavior but differ in morphology. Although there is a paucity of literature on aquatic isopod, hermit crab, and brachyuran grooming, particularly with regard to species taxonomically close to the terrestrial crustaceans, minor differences in grooming behavior and morphology between the two groups appear to be the rule.
