Crabs will eat almost anything such as particles of flake food that sink to the bottom of the aquarium and other bits of food. For this reason they are excellent scavengers and help improve the water quality by reducing the amount of uneaten food in the aquarium.
They can live in most any basic aqaurium conditions.
This site was created to get straight to the point. Below are some tips on keeping Aquarium Crabs. Send any additional information or questions to Ask An Expert
Compatibility: Crabs seem to be too slow to catch most fish. The Crabs wave their claws at fish but don't ever seem to catch a fish, unless the fish is sick and crashed on the bottom. These Crabs will quarrel among themselves, so be sure each one has plenty of room and don't crowd too many in the same aquarium. One Crab per square foot of bottom area is enough. So, for example, a standard 10 gallon aquarium would have about 2 Crabs. A larger 40 gallon aquarium has about four square feet of bottom area, which is room for about 4 Crabs.
Crabs are escape artists, if you have the smallest peice of air tubing coming out the back of your tank they will get out! Make sure your tank is 100% completely covered.
These Crabs will escape from your aquarium unless you make sure there is nothing near the vertical pieces of glass for at least 4" above the bottom of your aquarium.
They help aerate the substrate a little. I use sand and they are very good for it; they sift through the very top layer about 1/4 inch all day long looking for food which helps keep the sand loose etc.
Red Claw Crabs and the Gold Fiddler Crabs are truly aquatic and do not need to get out of the water.
It would be best to give Crabs a choice by placing a big rock or pile of rocks that extend up out of the water and allow the Crabs to climb up and out of the water.
Scavenge bottom of tank - helps keep it clean
Crabs can live for a few years and grow to be about 2.5" across the shell.
Don't allow the crabs to climb out, they are escape artists if you have the smallest peice of air tubing coming out the back of your tank they will get out!
There are several species of hermit crabs that are common in the marine aquarium trade. These omnivorous or herbivorous species are useful in the household aquarium as scavengers, eating algae and other debris.
While most species available in pet stores are small like those listed above, and are simply scavengers, others may grow quite large (some on the Pacific coast can grow to 30 cm / 12 inches) and may eat coral, clams and other crustaceans.
Most marine hermit crabs will appreciate a salinity of between 1.023 and 1.025 (measured in specific gravity), and temperatures between 4–14°C (temperate species) and 24–27°C (tropical species), with a good bed, algae to graze on and a variety of shells to change into. They will happily switch shells frequently if given the opportunity - an interesting display to watch.
Follow the above recommendations and you should have a joyful Aquarium Crab experience. Send any questions, comments or pictures to Ask An Expert If you are interested in helping out visit our contributions page.
Vierke, J. 1986 Vierke's Aquarium Book. T.F.H. Publications, Neptune City, NJ. 352 pp.