Gills of pinnotherid crabs are groomed by setose epipodite extensions of maxilliped mouthparts. Unlike other Brachyura, some pinnotherid genera lack epipodites on maxilliped 2. Plumodenticulate setae similar to those found in other Crustacea represent the majority of grooming setae found on maxillipeds, maxillae, and maxillules in pinnotherids. Structurally more complex setae with anchor-shaped outgrowths were found in 7 of 19 investigated genera. Plumodenticulate setae with anchors are located on maxillules, maxillae, and maxilliped 1 epipodites of Opisthopus and Dissodactylus, whereas Pinnaxodes and Pinnotherelia carry them also on maxilliped 2 and 3 epipodites. In Anomalifrons and Xenophthalmus, some plumodenticulate setae on maxilliped 3 epipodites are armed with facing unequal recurved hooks, resembling ship chocks, in addition to anchors. Only one pair of chocks occurs per seta. Plumodenticulate grooming setae with long double prongs were found exclusively on four different mouthparts in Mortensenella. Larvae and early postlarval instars of Dissodactylus have a particular type of plumodenticulate grooming seta. These setae cover most of maxilliped 1 epipodite and the distal part of maxilliped 3 epipodite and are clustered on the anteroventral surface of maxillules and medially on maxillae. Some of these plumodenticulate setae develop anchorlike outgrowths between setules and denticules in larger crabs. Anchors appear about 2 months after hatching as a single pair per seta, with more pairs being added proximally to the first pair during consecutive stages. On maxillules, anchor setae become twice as numerous as plumodenticulate setae. On maxilliped 1 epipodites, proportions remain about constant. All anchor setae grow at about the same rate as the appendage on which they originate. Anchor setae on maxilliped 1 epipodites of the largest adult crabs may be over 2 mm long and with up to nine pairs of anchors, whereas those on maxillules are less than 1 mm long, bearing no more than six pairs of anchors. On maxillules, setae with two pairs of anchors remain the most common. On maxilliped 1 epipodites, the most common anchor seta for almost every third instar carries an additional pair of anchors, starting with one pair in instar 6 to seven pairs in instar 27. Anchor setae are also found proximally on the protopodite of maxillae in the smallest juvenile crabs but do not develop anchors until close to maturity. On average, each maxilla carries one anchor seta equipped with a single pair of anchors. Anchor setae were not found on any other appendages or cuticular surfaces. Grooming setae seem to lack chemosensory characteristics. Plumose and denticular outgrowths are interpreted as brushing and combing devices. Anchors, chocks, and double prongs seem particularly suited for dislodging of larger objects or organisms, introduced as larvae by the respiratory current, and also might aid in stripping other plumodenticulate setae of accumulated debris.