Aquariums have the option of housing so much more than fish. Freshwater aquarium crabs can be a fun and beneficial addition to any fish tank!
The crabs you get from pet stores are tiny, averaging between one and four inches. Each crab should get one square foot of aquarium floor. If you put too many in your aquarium, they will get territorial and fight. You will find two kinds of freshwater crabs sold in pet stores: true and untrue. True crabs are characterized by a flat shell and five pairs of legs, the first two being pinchers. Their abdomens are folded under their cephalothroax (their major body part). Examples of true crabs are Fiddler (the most popular among aquarists) and Horseshoe. Untrue crabs keep their bodies in a seashell. They are categorized with true crabs in pet stores because they are short crustaceans with hard exoskeletons and ten legs.
Crabs are great for aquariums. They are scavengers and will eat organic matter such as decaying plants, dead fish, or decaying food. Because they walk and climb but do not swim, they also stir up substrate. Like land dwelling plants, underwater plants also need their soil or gavel cultivated. Having crabs in your tank will cultivate your aquarium’s greenery and help it grow. The most significant benefit crabs have to offer is probably their appetite for algae. If you have an algae problem, get a crab or two to keep it in check. These critters, as well as snails, make meals out of the stuff. Keep in mind nothing is a substitution for maintaining the aquarium yourself.
Another benefit of freshwater crabs is the fun behavior they display! These guys will climb, scuttle and hide. If you stick any kind of decoration in your tank, they will not hesitate to explore every inch of it. They will even climb up the side of tanks and try to escape if they find a hole in the hood! Intriguing behavior is perhaps why Fiddle crabs are one of the most popular. They are nocturnal and scuttle around quite a bit. The males are interesting in appearance because they have one small claw and the other one is supersized! Adding crabs to your aquarium will make it much more unique.
Bear in mind that crabs are slightly higher maintenance than some fish. Their water has to be kept at 70-82 degrees Fahrenheit. Crabs assist in keeping water clean, probably because they cannot live in it themselves if it gets too dirty. Make sure your crabs are living in clean water and test it often. Not all crabs can live in water forever. Most need to visit dry land. You can give them the land by putting a mound of gravel in your tank. Have it sit above the water and slope underwater.
Crabs crave a varied diet. Switch up their feed between flakes, frozen, and live food. They will still eat snacks of dead fish and feces in between meals! Lastly, think of the fish already in your tank. Some fish like to eat crabs, and crabs will eat tiny, bottom-dwelling fish. It does not do an aquarium any good if its inhabitants eat each other! Do some careful research before accidentally turning your aquarium into an underwater version of ‘Lord of the Flies’.