Florida Fiddler Crab

 Quick Care Facts

• Care Level: Easy   • Temperament: Peaceful   • Maximum Size: 2"
• Minimum Tank Size: 10 gallons   • Water Conditions: 74-84° F, KH 12-30, pH 7.8-8.4
• Color Forms: Brown, Grey, Black, Red, Yellow   • Diet: Omnivore   • Origin: Florida
• Family: Ocypodidae   • Species: Crabs   • Aquarium Type: Crabs

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The Florida Fiddler Crab (Uca sp.) is a variety of Fiddler Crab that is most commonly found within the aquarium hobby. Florida Fiddler Crabs are from the genus Uca, which consists of over 100 species of crabs commonly found in brackish coastal areas like mangrove swamps, salt marshes and sandy or muddy beach areas. The Florida Fiddler Crab is commonly seen within the aquarium hobby due to its small size, ease of care and ready availability. The species is often sold under a variety of common names including: Florida Fiddler Crab, Fiddler Crab, Signal Crab, Mini Crab, Calling Crab and Uca Crab.

All crabs from the genus Uca are semi-aquatic in that they spend part of their time underwater and part of their time on land. To thrive in the aquarium environment the Florida Fiddler Crab will need either brackish water or freshwater with some aquarium salt added in order for the crab to be able to molt correctly. Also important in the molting process is adequate calcium and trace minerals, which can be provided by salt mixes or aragonite based substrates.

Florida Fiddler Crabs will also need access to some area within the aquarium that is above the waterline. Ideally an area made up of sand, mud or a mix of the two combined with rocks, driftwood, shells of similar items under which to hide. The land portion of the aquarium should contain substrate that is deep enough to allow the crab to burrow under the sand, while providing a gradual transition into the water portion of the aquarium to allow easy access to both sections of the tank.

Despite only spending part of their time in the water, the Florida Fiddler Crab requires proper water conditions in order to thrive. Since the crab spends a good portion of its life in the water, proper water quality and aquarium conditions should be maintained via a proper aquarium filter, heater and partial water changes. Florida Fiddler Crabs are more than capable escape artists who use power cables, filter tubes or other items that go in and out of the aquarium to climb out and escape. Hobbyists will need to have a secure and tight fitting lid on the aquarium to prevent the crab from climbing out.

As with all crabs, the Florida Fiddler Crab is a true omnivorous scavenger that will consume a wide variety of organic material. Florida Fiddler Crabs will happily scavenge decaying plant matter, meaty foods and even detritus. Hobbyists should feed them flake foods, mini pellets, algae wafers or pellets, small worms or brine shrimp.

Fiddler Crabs have a fairly short lifespan of approximately 1 to 2 years; however, during this time they live very active and interesting lives. They are avid explorers and feeders who will actively scavenge the entire aquarium looking for morsels of food and new places to explore.

They are also avid breeders with males on the look out for suitable females which to court. During courtship, the males will wave their over sized claws above their head and tap them on the ground in an effort to attract nearby females. As one can imagine, multiple males within the same aquarium will often fight over the available females.

Occasionally during these scraps a male crab will lose their big claw, in which case the smaller one will begin to grow larger and the lost claw will regenerate into a new (small) claw. Only the male of the species has this large brightly colored claw, with which it "calls" or signals the female crabs. The females simply have two small claws that are grey or tan in color.