Overview
The Fiddler Crab (Uca spp.) is a intermediate brackish species known for its variable (brown, blue, red by species) coloration. Males have one giant claw. Land and Water.
Origin & Appearance
Origin: Worldwide tropical coasts.
Colors: Variable (Brown, Blue, Red by species).
Body Shape: Crab (wide carapace). Typical adult dimensions: 3.5 x 5.0 x 2.0.
Sexual Dimorphism: Moderate; males have narrower abdomen.
Tank & Water Requirements
| Min Tank Size | 11 gallons |
| Temperature | 72–82°F |
| pH Range | 7.5–8.5 |
| Water Hardness (GH) | 10-25 |
| Bioload | low |
| Oxygen Demand | medium |
| Plant Safe | mostly |
| Aquarium Position | Land and Water |
Behavior & Activity
Semi-terrestrial; males wave oversized claw in courtship display; sideways scuttling on land and water; burrows in mud
Speed: 20/100Aggression: 4/10diurnal
Breeding
Difficult; larvae need saltwater
Common Diseases
💊 Molt failure💊 bacterial
Expert Notes
Males have one giant claw; semi-terrestrial