Introduction
The Plagusiidae are a small family of grapsoid crabs comprising 6 genera and 20 species (extant taxa) with a wide distribution in tropical and temperate regions. Although they are typically found in rocky shore intertidal and shallow subtidal habitats, two genera are restricted to deep water on continental slopes. Some rocky shore species are able to “raft” in the pelagic zone on floating timber and sea turtles. A number of species are used as bait by rock fishermen. — John W. Short, 2026
Diagnosis
Carapace subcircular to quadrate; anterolateral margins with one to several teeth or spines; pterygostomial and subhepatic regions not covered in reticulated network of short, hooked setae; third maxillipeds partially covering buccal cavern, merus and ischium without oblique setose crest; legs not paddle-like; press-button abdominal locking mechanism; male abdomen with segments 3–6 or 3–5 fused; male and female genital openings sternal. — John W. Short, 2026
