MOREHEAD CITY, N.C. (WNCN) — The N.C. Division of Marine Fisheries is asking people to be on the lookout for blue land crabs and to report sightings.

These crabs are a non-native species to the Carolinas that look like an enormous fiddler crab, the agency said.

Adult blue land crab spotted in Emerald Isle, N.C. (Photo: D. O’Leary)

There have been recent reports of blue land crabs spotted in both North and South Carolina. Biologists want to learn more about where the this crab species is spreading, according to the agency.

The crabs are native to the Atlantic coast from Brazil to South Florida, but occasional sightings of the large crabs have been reported in South Carolina since 2008.

Whether the species arrived through natural expansion of its range or human-mediated sources is not clear.

Researchers do not yet know the extent of the crab’s distribution throughout the Carolinas nor its impact on the environment and other wildlife, the agency said.

Despite their name, the crabs vary widely in color. Adult males tend to have the characteristic blue-gray coloring, but females can also be white or ash-gray, and juveniles can range from orangish to dark brown to purple. They’re unusually long-lived and slow-growing among crabs, reaching maturity at four years of age and surviving up to 11 years.

Young blue land crabs, like this male, can range in color from orange to dark brown to purple. (Photo: E. Weeks/SCDNR)

“Blue land crabs are difficult to catch. In addition to their speed at retreating into burrows deep below ground, the crabs possess a large claw that they can use to dexterously defend themselves,” a news release stated.

Biologists encourage people to snap a photo and report the date and the location of sighting here. Biologists believe the crabs may be more visible following heavy rains which can drive them out of their burrows.