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Atlantic sand fiddler crab

Leptuca pugilator

Also known as Pink Atlantic sand fiddler crab, Sand fiddler crab, Calico fiddler crab, Uca pugilator

BrackishCrab

Atlantic sand fiddler crab (Leptuca pugilator)
xpda · CC BY-SA 4.0

Care at a glance

Temperature
68–82°F
20–28°C
pH
7.8–8.4
Adult size
1 in
2.5 cm
Minimum tank
11 gal
40 L
Temperament
Mostly peaceful
Social behavior
Social
Tankmates
With caution
Swim level
Bottom
Diet
Omnivore
Difficulty
Medium
Breeding
Hard
Rarity
Common
Family
Ocypodidae
Origin
US Atlantic and Gulf coasts, Massachusetts to Texas

Overview

The Atlantic sand fiddler crab is a mostly peaceful colony crab for the beach of a brackish paludarium. It suits a keeper with a little experience.

Did you know

If a male Atlantic sand fiddler crab loses his big claw in a fight, he regrows one on the same side. Over the next molts the new claw grows back smaller and weaker than the original, and the small feeding claw stays small. The old story that the crab switches hands is a myth.

Caring for the Atlantic sand fiddler crab

The Atlantic sand fiddler crab is a shore animal that spends its time on the sand and at the water's edge. It drowns in a tank with no way out of the water, and it will not use a deep tank at all. Give it a brackish paludarium with a shallow pool, a tight lid and a sloped sand beach several centimeters deep to burrow in. A group needs a footprint of at least 11 gal (40 L).

Shops sell it as a freshwater crab, but in fresh water it fades over a few months. Mix marine salt to a specific gravity of 1.005 to 1.015. Keep the water at 68 to 82°F (20 to 28°C), with a pH of 7.8 to 8.4.

Feed sinking pellets, algae wafers, blanched vegetables and frozen bloodworm. Leave cuttlebone in the water for the molt.

Fiddler crabs are colony animals, peaceful apart from males sparring over burrows. Keep a group with more females than males. Brackish snails are the only easy company, and most fish do not fit a beach setup.

Males carry one huge claw, on either the left or the right side, and one small feeding claw. The large claw can be 4 cm long. The larvae drift in the sea as plankton for weeks, which makes breeding it in captivity hard.

Good to know

The Atlantic sand fiddler crab is Leptuca pugilator, in the family Ocypodidae. It was sold for decades as Uca pugilator, until the 2016 revision moved it to Leptuca. It feeds by scooping up sand and sorting out algae and detritus with its mouthparts, then dropping the cleaned sand as little pellets. A fiddler crab lives only about one to three years.

In the wild

The Atlantic sand fiddler crab lives on sandy and muddy shores from Cape Cod to Texas. It digs burrows above the waterline along tidal creeks and salt marsh edges, often in colonies of thousands.

Common questions

What size tank does an Atlantic sand fiddler crab need?

An Atlantic sand fiddler crab needs at least 11 gal (40 L). It spends most of its time in the bottom.

What temperature and pH does an Atlantic sand fiddler crab need?

An Atlantic sand fiddler crab is comfortable at 68–82°F (20–28°C) with a pH of 7.8–8.4.

What does an Atlantic sand fiddler crab eat?

An Atlantic sand fiddler crab eats sinking pellets, algae wafers, blanched vegetables and frozen bloodworm. Leave cuttlebone in the water for its molt.

How big does an Atlantic sand fiddler crab get?

An adult Atlantic sand fiddler crab reaches about 1 in (2.5 cm).

How can you tell a male Atlantic sand fiddler crab from a female?

Males have one huge claw and one small feeding claw, with the huge one on either side. That big claw can reach 4 cm long.

How does an Atlantic sand fiddler crab breed?

Atlantic sand fiddler crab larvae drift in the sea as plankton for weeks. That makes breeding the crab in captivity hard.

Related species