How to Add Crayfish to Your Tank

Crayfish Facts

• Crayfish are related to lobsters but they are typically much smaller in size - most species grow to a maximum length between 1.5 and 8 inches. These creatures can be found in a variety of natural habitats, but they are most widely distributed in the Northern hemisphere. More than 300 species of crayfish can be found in North America alone and many additional species are known to inhabit South America, Asia, Europe and Australia. The bodies of crayfish are covered a flexible exoskeleton that the animal sheds as it grows and matures. In the freshwater tank, these creatures feed on detritus, plant matter and small invertebrates and will accept a variety of live and frozen foods.

Choosing a Species

• While a large number of crayfish species have been identified, a limited number are available in the aquarium trade. When shopping for crayfish, you may notice that many pet stores use the term "lobster" interchangeably with "crayfish." Some of the more commonly sold crayfish species include Florida Lobsters, Orange Dwarf Crayfish, Blue Knight Lobsters, White Ghost Lobsters and Black Scorpion Lobsters. To make an informed decision about which species to purchase, consider the type of aquarium you want to add your crayfish too. Some species, like the Black Scorpion Lobster, can grow up to 12 inches and thus require a very large tank. Others come from brackish environments, and thus can tolerate low salinity levels in the home aquarium.

Tank Preparations

• Because freshwater crayfish are found in a wide range of habitats, they tend to adapt well to a variety of tank conditions. Crayfish are likely to do well as long as the tank temperature is kept between 68 and 85 degrees Fahrenheit and these creatures are able to tolerate a wide range of pH from 6.5 to 8.0. The main requirement these creatures have in the home aquarium is their need for cover. Prepare your crayfish tank with plenty of rocks, aquatic plants, overturned clay pots and even lengths of plastic pipe. Having places to hide will limit the amount of stress your crayfish experience. Many species of freshwater crayfish also prefer sand or fine gravel substrate in which they can burrow.

Compatible Tank Mates

• In their natural environment, fish are part of the diet of crayfish but due to their large claws, crayfish will not be able to catch species of small, quick-moving fish. Small species of crayfish can safely be kept in tanks with small tetras and livebearers such as mollies, swordtails and platies. Larger crayfish can also be kept with small fishes but are best kept with slightly larger species such as catfish, barbs, cichlids and labyrinth fish. In the home aquarium, crayfish are not likely to catch or eat fish unless the fish are sick or injured and are thus unable to escape.

Crayfish Care

• Although crayfish are scavengers and will likely find food among the substrate in your tank, it is wise to supplement their diet to ensure that they receive adequate nutrition. Freshwater aquarium crayfish will accept a variety of foods, including live or frozen snails, mussels, shrimp, worms and krill. They may also enjoy a supplemental diet of fresh vegetables such as corn, zucchini, carrots and cucumbers. The most important thing to remember when caring for crayfish is that they can be semi-aggressive and territorial. Limit your tank to one crayfish per 20 gallons for species up to 5 inches, and provide at least 40 gallons each for larger specimens.