Burrowing-crab
Guides
Cardisoma guanhumi
blue land crab, great land crab
Cardisoma guanhumi is a large terrestrial crab native to tropical and subtropical Atlantic coastlines of the Americas. Adults exhibit striking sexual dimorphism in coloration and claw morphology, with males developing enlarged claws and typically displaying deep blue coloration while females remain lighter. The species constructs deep burrows in coastal soils that extend to the water table, enabling survival in terrestrial environments despite reproductive dependence on marine habitats for larval development. Populations have declined across much of their range due to overharvesting and habitat degradation, leading to protected status in several countries including Puerto Rico and Colombia.
Minuca longisignalis
longwave gulf fiddler, Gulf Marsh Fiddler Crab
Minuca longisignalis, formerly Uca longisignalis, is a fiddler crab endemic to Gulf of Mexico salt marshes. It exhibits striking reproductive seasonality characteristic of warm-temperate lineages, with ovigerous females appearing no earlier than April and peak ovigery in June. The species constructs burrows in vegetated marsh areas, with burrow density and depth varying by elevation and distance from shoreline. It co-occurs with congeners such as Uca spinicarpa, though shows substrate preferences for different clay compositions.
Ocypode quadrata
Atlantic Ghost Crab
Ocypode quadrata, the Atlantic Ghost Crab, is the only ghost crab species occurring along the Atlantic coast of the United States. It inhabits sandy beaches from Massachusetts to tropical regions of the Western Atlantic. The species has been demonstrated to possess notable cognitive abilities including operant conditioning, landmark-based wayfinding, and mirror self-recognition. It functions as a predator, scavenger, and deposit-feeder in coastal ecosystems, and is widely used as a bioindicator for sandy beach health.
Uca minax
red-jointed fiddler crab, brackish-water fiddler crab
Minuca minax is a fiddler crab species distinguished by its tolerance for low-salinity and freshwater habitats, extending farther inland than most congeners. Males possess one greatly enlarged claw with red joints, the source of its common name. Formerly classified in genus Uca, it was transferred to Minuca in 2016. The species is abundant in salt marshes and tidal streams along the U.S. Atlantic and Gulf coasts, with documented populations occurring more than 50 km from the sea.