Try to have at least a square foot of area per crab to prevent overcrowding and avoid territorial aggression. Leave a small portion of aquarium gravel above the water level, but not high enough where the crab can escape. Crabs prefer conditions where they can often come out of the water and dry themselves even though there are still several wrong notions that a crab can survive a fully submerge lifestyle.
Fiddler Crabs
Diet Food may be flaked, dried, pelleted, frozen, or live,and algae-based pellets. Thaw frozen foods before feeding. Feed a variety of food to ensure complete nutrition
The fiddler crab is one the more popular crustaceans added by freshwater aquarium enthusiasts. They are great scavengers of leftover food particles and algae, thus can help prolong clear water conditions. Brackish waters (where the sea and the river meet) are their true natural habitat, thus incline to slightly salted waters – one teaspoon per gallon ratio, although they can also strive on freshwaters. They are great to keep with Monos, puffer fish and various other brackish water species.
Freshwater Red-Clawed Crab
Another popular choice is the Freshwater Red-Clawed Crab where their colorful appearances have given it a better stock demand among pet shops than the fiddler crabs. Just like the fiddler crabs, it prefers brackish waters, but can also live in freshwater. Also a scavenger and natural water filter, but with a slightly bigger appetite. This crab will eat most varieties of smaller fish including danios, white clods, swordtails and anything of a similiar 1 inch size.
Soap Dish Crabs and Rusty Crabs
Soap dish crabs and rusty crabs are some of the examples that should be avoided in integrating into your aquariums with small fishes. They are highly predatory and will not hesitate to pinch anything that passes by them. The soap dish crabs do not mix well with others and will even kill its own kind when encountered. They are given the name soap dish crabs for their reputation of being separated individually in a soap dish box to avoid killing each other during transport and this definitely will not be a good idea for them to be your freshwater aquarium crabs.
The Bottom Line
In truth, all freshwater crabs have a potential to be a great addition to your freshwater aquariums as long as the conditions can maintain natural harmony between species. Although for being practical and simplistic, the Fiddler Crab and the Fresh-Red Clawed Crab are the obvious choice for being one of the least troublesome crabs to maintain.
