Semi-terrestrial
Guides
Aratus
mangrove tree crabs
Aratus is a genus of semi-terrestrial sesarmid crabs comprising at least two recognized species, with Aratus pisonii (mangrove tree crab) being the best studied. These crabs are specialized arboreal inhabitants of mangrove ecosystems throughout the Neotropics, occupying the canopy and prop root zones. The genus has gained scientific attention due to documented climate-induced range expansion along the Atlantic coast of North America, with populations establishing in salt marsh habitats beyond the historical mangrove range limit. Research on Aratus pisonii has revealed significant phenotypic plasticity in life history traits, behavior, and physiology across native and novel habitats.
Armases
square-back American marsh crabs
Armases is a genus of sesarmid crabs comprising approximately 13 described species distributed across tropical and subtropical coastal regions of the Americas. These semi-terrestrial crabs inhabit salt marshes, mangroves, and estuarine environments, with some species exhibiting notable movement between marine and terrestrial habitats. Several species have been extensively studied for their larval development, metabolic ecology, and role in ecosystem energy transfer. The genus includes both species with larval export strategies to continental shelves and those breeding in supratidal rock pools.
Uhlorchestia uhleri
beach hopper, salt marsh amphipod
Uhlorchestia uhleri is a talitrid amphipod endemic to salt marshes along the Atlantic coast of North America. This semi-terrestrial crustacean is tightly associated with salt marsh vegetation, particularly Spartina grasses, and exhibits morphological adaptations for life in intertidal environments including reduced gills and modified pleopods. The species plays a role as a detritivore in salt marsh ecosystems and serves as prey for marsh predators.