Meet the Flame-backed Fiddler Crab

Article | Updated 6 years ago

Image of Flame-backed Fiddler Crab
Flame-backed Fiddler Crab
Clay Bryce

The Flame-backed Fiddler Crab, or Uca flammula, is also called the Darwin red-legs.

Image of Flame-backed Fiddler Crab

Flame-backed Fiddler Crab
Image copyright WA Museum 


This harmless crab can grow up to 3.5 cm (carapace width). It has a black carapace, and brilliant orange-red claws, one of which is larger in males. They live no more than two years. 


This Fiddler Crab is a detritivore, probing sediment in search of organic matter. 


The Flame-backed Fiddler Crab can be found in an area stretching from Mangrove Bay in Western Australia and north into the Northern Territory.  They inhabit sand or sandy mud, and are often found at the edge of mangroves

Breeding and Behaviour

Adult males have one small claw and one very large claw, which they use during courtship and combat. This is where the Fiddler Crab gets its name – when this big claw is being waved around, it looks as if the male crab is playing a fiddle.