Basics of Crayfish Care
Crayfish care, crawfish care, crawdad care - it's all the same. What you call the little critters depends a lot on where you live.
Crayfish are fresh water crustaceans that look like tiny lobsters, and to some extent like a shrimp with claws. They make quite interesting pets when placed in a home aquarium, but crayfish care is sometimes a little more involved than caring for fish. It usually isn't a good idea to put fish and crayfish in the same tank, unless the fish are larger than the crayfish. If not, the fish will soon be gone, even the fast swimmers.
The crayfish is a patient and efficient fisherman. It's not all that one-sided, however. Some aquarium fish will eat crayfish. Best to keep the two species apart.
Housing - A key item in any discussion on crayfish care has to be housing, or the habitat the crayfish will be calling home. A single crayfish should have an aquarium tank that is at least 10 gallons in size. It's not so much the depth of the water that's important as it is the surface area the crayfish has to move around in.
Water Depth - Water depth is important too, but mainly so that there is enough of a volume of water so that it can keep relatively clean between changing.
One important aspect of crayfish care is that when a crayfish is initially placed in the water, it should not just be dropped into the tank. Air bubbles trapped in the gills may cause it to drown. The recommended procedure is to hold the crawfish upside down for a brief time just under the surface of the water, to let the air bubbles escape. When holding a crayfish, grasp it near the center of its shell from above to avoid getting pinched.
Companionship Not Needed - Speaking of pinching, the crayfish is not a terribly social creature and tends to be both aggressive and territorial.
Except for breeding purposes, more than a single crayfish in one tank is usually not recommended. In a larger tank, several crayfish can be placed if there are plenty of hiding places, but this could be a hassle when the water needs to be changed or when the tank is to be cleaned out.
Even if there are plenty of hiding places, don't put different species of crayfish (there are about 20 in North America alone) in the same tank. They'll kill one another.
Food - When not eating pet aquarium fish or each other, crayfish are primarily vegetarians and scavengers, and can be fed bits of:
One has to clean up after them, removing uneaten food, so as not to allow the water to become fouled. This can be a challenge at times, since if the crayfish has a cave or small hiding place, which it should have, it will sometime hoard food and store it there. Such a hoard should be removed before too much time passes.
In spite of its tendency towards vegetation, most crayfish love shrimp pellets, and pellets make an ideal food for a pet crayfish. A little variety from time to time won't hurt, but if a pet crayfish is in your plans, seek out a source of shrimp pellets.
Water - As far as water is concerned, untreated water or pond water is best.
If chlorinated tap water is to be used, it should be left to sit in the open air overnight before putting it into the tank, to let the chlorine dissipate.
Most crayfish species are cold water fish, so the tank does not need to be heated, in fact its best if the water temperature can be kept at room temperature or slightly below.
The water should be filtered and oxygenated, since if the oxygen content in the water gets too low, the crayfish will drown. The filter input should be protected to the extent that the crayfish cannot get trapped in it or clog it.
Finally, the crayfish needs a substrate of sand or very small gravel to burrow in. This, and a place to hide, are essential to the creature's well-being. A section of PVC pipe will serve nicely as a hiding place.