Gecarcinucidae

Gecarcinucidae is a family of freshwater crabs in the order Decapoda. Members are primarily found in tropical and subtropical Asia and the surrounding Australasian region, where they inhabit rivers, streams, forest creeks, floodplains, and in some cases brackish lagoons. They are adapted to life in freshwater and many species spend most of their lives away from the sea, with some showing burrowing behavior to endure dry periods.

Taxonomy and characteristics are variable across the family. Gecarcinucidae comprises multiple genera and a large number of species, with classifications having shifted as new morphological and molecular data have become available. Diagnostic features used to distinguish gecarcinucid crabs include aspects of the carapace shape and the structure of reproductive appendages in males, though species delimitation remains challenging due to high diversity and regional endemism.

Ecology and life history vary among genera but share a reliance on freshwater habitats. These crabs are generally omnivorous, feeding on detritus, plant material, algae, and small invertebrates. They are often nocturnal and may be active along stream banks or within forested habitats. Reproductive strategies range across genera and typically involve some form of parental care, with females carrying eggs until hatching and a diversity of developmental patterns observed among species.

Conservation concerns for Gecarcinucidae include habitat degradation, pollution, and hydrological changes that affect freshwater systems. Many species have restricted ranges and are sensitive to environmental disturbance, making ongoing survey and habitat protection important for conservation planning.