Introduction
The family Sesarmidae is a pantropical-subtropical group comprising 50 genera and over 350 species (extant taxa) typically found in mangrove estuaries. Most species are semiterrestrial in the upper littoral and supra-littoral zones where they burrow, hide in crevices and logs or climb on mangrove trees. A number of genera are also restricted to fresh water, most notably Geosesarma with over 75 species. — John W. Short, 2026
Diagnosis
Carapace quadrangular; anterolateral margins often unarmed or with 1–2 teeth (rarely more); pterygostomial and subhepatic regions covered in reticulated network of short, hooked setae; third maxillipeds leaving wide rhomboidal gap when closed, merus and ischium with oblique setose crest; legs not paddle-like; male abdomen typically with 7 free segments; male and female genital openings sternal. — John W. Short, 2026
