Freshwater aquarium crabs can be kept by themselves or within a community tank with other fish. You have many great choices for a freshwater aquarium, attractive for their interesting looks and behaviors or their scavenging tendencies. Most crabs serve as a cleanup crew for an aquarium, removing the leftover fish food, decaying plant matter and other fishy buildup from the bottom of the aquarium.
The red-clawed crab is a popular one. It thrives best in brackish water with fish that will not try to eat the crab. Red-clawed crabs grow to up to 2.5 inches and live about four years. They are not picky when it comes to food and make great scavengers, but you may need to offer a dry food or vegetable to supplement their diet. Be careful about keeping the lid on tight, because the red-clawed crab may try to escape.
The fiddler crab is also referred to as a mini crab. The species thrives best in water that is slightly brackish and in an aquarium with an internal filter. Mini crabs will grow to up to 2 inches. They are usually peaceful crabs that are fairly easy to care for; they can be quite interesting to watch while they are scavenging for food. Fiddler crabs spend most of their time climbing and hiding in driftwood, rocks and other decorations on the aquarium floor.
Gold Claw Crabs
Gold claw crabs have one claw larger than the other and will wave it at other crabs to communicate and as part of its mating ritual. These crabs live up to 2 years, as long as the water is kept clean and plenty of decaying material is available for them to scavenge. This is a small crab species, topping out at 1.5 inches, but it can be somewhat aggressive with tank mates. Gold claw crabs need some land in their environment, but be careful of the aquarium lid, because they will escape.
Soap Dish Crabs
The soap dish crab gets its name because it is often shipped in a soap dish, each crab by itself to prevent one from killing another. It has many aliases, being called rainbow crab, moon crab, patriot crab and other names. These crabs can be quite aggressive, and will eat other crabs and fish. Many fish keepers still enjoy them because of their brightly colored bodies, feeding them live fish, black worms, shrimp and other creatures. These crabs thrive best in brackish water.
- Shrimps, Crayfishes, and Crabs in the Freshwater Aquarium; Uwe Werner
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