Uca pugilator, the sand fiddler crab is a small fiddler crab

Fiddler crab

A fiddler crab, sometimes known as a calling crab, may be any of approximately 100 species of semi-terrestrial marine crabs which make up the genus Uca. As members of the family Ocypodidae, fiddler crabs are most closely related to the ghost crabs of the genus Ocypode. This entire group is composed...

 found in sandy or muddy intertidal areas, or mangrove

Mangrove

Mangroves are various kinds of trees up to medium height and shrubs that grow in saline coastal sediment habitats in the tropics and subtropics – mainly between latitudes N and S...

-covered ground, where it digs its holes in the root-filled ground. It uses these holes for shelter from the elements and predators. The carapace

Carapace

A carapace is a dorsal section of the exoskeleton or shell in a number of animal groups, including arthropods such as crustaceans and arachnids, as well as vertebrates such as turtles and tortoises. In turtles and tortoises, the underside is called the plastron.-Crustaceans:In crustaceans, the...

 is a square shape, tapering slightly to the rear. The space between the eyes is much shorter than the eyestalk

Eyestalk

In anatomy, an eyestalk is a protrusion that extends the eye away from the body, giving the eye a better field of view than if it were unextended. It is common in nature and in fiction....

. The males have one extremely enlarged claw

Claw

A claw is a curved, pointed appendage, found at the end of a toe or finger in most mammals, birds, and some reptiles. However, the word "claw" is also often used in reference to an invertebrate. Somewhat similar fine hooked structures are found in arthropods such as beetles and spiders, at the end...

, which they use to claim their territory and fight with other males. It is common for males to lose claws in the battles. When this happens, the claw regenerates and the opposite side begins to enlarge. Fiddler crabs are right or left clawed. The inside of these claws are also very smooth, unlike its other close relatives Uca pugnax

Uca pugnax

The Atlantic marsh fiddler crab, Uca pugnax, is a common fiddler crab of the Mid-Atlantic and northeastern United States. Marsh fiddlers dig burrows in the muddy or sandy banks of salt marshes, which they use to protect themselves from predators, high tide, and extreme temperatures, They feed by...

and Uca minax.

Geographic distribution

Uca pugilator is one of only 5 species of fiddler crab

Fiddler crab

A fiddler crab, sometimes known as a calling crab, may be any of approximately 100 species of semi-terrestrial marine crabs which make up the genus Uca. As members of the family Ocypodidae, fiddler crabs are most closely related to the ghost crabs of the genus Ocypode. This entire group is composed...

s found primarily in temperate areas. The species occurs on the east coast of North America

North America

North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

 and in the Gulf of Mexico

Gulf of Mexico

The Gulf of Mexico is a partially landlocked ocean basin largely surrounded by the North American continent and the island of Cuba. It is bounded on the northeast, north and northwest by the Gulf Coast of the United States, on the southwest and south by Mexico, and on the southeast by Cuba. In...

, having been found as far north as Massachusetts

Massachusetts

The Commonwealth of Massachusetts is a state in the New England region of the northeastern United States of America. It is bordered by Rhode Island and Connecticut to the south, New York to the west, and Vermont and New Hampshire to the north; at its east lies the Atlantic Ocean. As of the 2010...

 and as far south as Texas

Texas

Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...

 and Florida

Florida

Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...

. This species has also been reportedly been found in the Bahamas.
They may also be found in the warmer waters of the Atlantic along the West coast of Africa.

Habitat

Sand fiddler crabs can be found in estuarine and coastal areas or sheltered shores with sandy or muddy substrates. They are frequently found in areas bordering marshes

Marsh

In geography, a marsh, or morass, is a type of wetland that is subject to frequent or continuous flood. Typically the water is shallow and features grasses, rushes, reeds, typhas, sedges, other herbaceous plants, and moss....

and along the banks of tidal streams. They can be found in these areas in large numbers – thousands to millions.