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Blue Crayfish {Procambarus Alleni} Care Guide

Last Updated July 24, 2020
Blue Crayfish

If you’d like to keep a truly beautiful creature and you fancy the idea of owning something a little bit different from the run-of-the-mill tropical fish that your friends have, how about a Blue crayfish? Blue crayfish are pretty easy to care for, and they’re not too picky when it comes to food and water quality, so we reckon a beginner would do well with one of these freshwater lobsters as a pet.

However, unfortunately, these quirky-looking animals are not suitable for life in a community tank, so you’ll need a species-specific setup. That said, the Blue crayfish does make a fascinating pet.

In this article, we tell you everything that you need to know about keeping and breeding the immensely popular Blue crayfish.

Background

The Blue crayfish, Procambarus alleni, is also sometimes known as the:

  • Sapphire crayfish
  • Electric Blue crayfish
  • Florida crayfish
  • Blue lobster
  • Everglades crayfish

Procambarus alleni is a native species of Florida to the south of the panhandle. These crayfish inhabit freshwater streams, ditches, marshland, flood plains, and wetlands. The creatures are also sometimes seen in California and parts of Europe, and it’s thought that these originate from released aquarium pets.

Blue crayfish prefer still or very slow-moving water, and they can even survive during dry spells by burrowing down into the substrate, where they can utilize any moisture they find there to stay hydrated. Although these crayfish are primarily a freshwater species, they can be found living in brackish waters, where salinity levels can be up to 18ppt (parts per thousand).

Appearance

Procambarus alleni grows to around four to five inches in length, although some wild examples have been found that measure closer to seven inches long. These crayfish typically live for up to five years in captivity with the appropriate care and feeding.

Over the years, breeders and amateur enthusiasts have bred these crayfish to be a vibrant, bright shade of electric, cobalt blue, and the specimens that you find for sale in fish stores are always a bright blue color. However, in the wild, Procambarus alleni may also be found in a few other color morphs, including brown, white, orange, and red. All colorways are generally speckled with dots or paler patches.

Determining gender

It’s relatively easy to tell the boys from the girls when you’re choosing Blue crayfish to add to your setup.

Male Electric blue crayfish have very much bigger claws than female crayfish, and their tails are usually narrower too. Male crayfish also have two “claspers” behind their legs that are used to transfer sperm during mating. Females have a round-shaped sperm receptacle organ situated between the base of their last two pairs of legs.

If you’re in any doubt about the sex of a prospective purchase, ask an assistant in the fish store to help you.

Blue Crayfish

Mistaken identity

There is another species of crayfish that is almost identical to Procambarus alleni. The burrowing Cambarus monongalensis or Procambarus clarkii is also sometimes referred to as the Blue crayfish; however, these animals are endemic to Virginia, Pennsylvania, and West Virginia.

The only difference between the two species is the areola on the back of the Blue crayfish’s carapace. The areola is a small gap between the two pieces of the carapace and is not present on the Procambarus clarkii crayfish.

Behavior

Electric blue crayfish are nocturnal animals that venture out at night to feed and scavenge. Blue crayfish are borrowers, and they also like to hide away in caves and under rocky overhangs.

These creatures are highly territorial, and they can be very aggressive. For that reason, we don’t recommend that you keep multiple specimens in the same aquarium unless you have experience in keeping rays. However, if you do decide to take a chance and keep several Electric blue crayfish together, you must keep them in a very large tank and be prepared to provide plenty of hiding places so that the crayfish can keep well away from each other.

If you do plan on keeping a few Blue crayfish in the same aquarium, it’s a good idea to introduce all the crayfish at the same time. That strategy can be effective at reducing levels of aggression. If you start with one freshwater lobster and then add more, the original crayfish are more likely to view the new arrivals as territorial rivals and attack them.

Electric blue crayfish molting

Like all species of crustaceans, Procambarus alleni frequently molts as part of its growth process. Molting essentially entails the animal shedding its old exoskeleton.

After each molt, the animal’s size increases. Over the few days following the molt, the exoskeleton begins to harden, and a new shell is created. During the molting process, the crayfish will be vulnerable to predators, so it will hide for a few days while the new shell hardens.

How to tell if your Blue crayfish is starting to molt

You can tell when your Blue crayfish is beginning to molt by looking out for a few giveaway signs.

First of all, your lobster pet will go off his food. You will also notice that your usually busy, active crayfish slows down and becomes more lethargic. Don’t panic! Your pet isn’t sick. During the pre-molting period, the crayfish ingests calcium into his internal organs, rather than into his exoskeleton.

Electric Blue crayfish molt less frequently as they get older. So, when your pet is a baby, he will molt every few days. Juvenile Blue crayfish molt every one to three weeks, whereas an adult specimen molts between every four and eight weeks.

Once the crayfish has molted, it will eat the whole shed exoskeleton. That’s normal behavior that enables the crayfish to retain the calcium that the exoskeleton contained, which it utilizes to create its new shell. While your pet is busy eating the exoskeleton, you don’t need to feed him for a few days. Note that you will need to provide your crayfish with plenty of calcium so that the molts are complete, and the crayfish remains healthy.

Caring for Blue crayfish

Most crayfish species are pretty easy to look after in a captive environment. Here’s what you need to know.

Diet and nutrition

Procambarus alleni are omnivores, eating pretty much whatever plants and animals come within reach of their claws in the wild. In captivity, the opportunistic Electric Blue crayfish will feed on live plants, detritus that they find in the substrate, snails, and dead fish if you happen to miss any in your tank. You may also feed these creatures blanched vegetables such as peas, lettuce, potatoes, cucumber and carrots, sinking wafers, and pellets, dwarf shrimp tails, fish, crab pellets, bloodworms, and blackworms.

It’s also very important that you include some form of calcium supplement in the Blue crayfish’s diet to help keep the animal’s exoskeleton in good condition. Try offering your pet cuttlebones and eggshells, as well as proprietary calcium supplements.

Electric Blue crayfish should be fed every day so that they don’t predate on their tankmates. However, it’s important that you don’t overfeed your pets, and always remove any uneaten food from the tank after 24 hours.

Be warned. Blue crayfish will eat their tankmates, including other crayfish, given the opportunity!

Do Electric Blue crayfish eat plants?

Yes, they absolutely do!

Unfortunately, the Blue crayfish is extremely destructive around aquatic plants and will tear or uproot pretty much all species of rooted plants. However, you can use floating plants relatively safely if you want to give your pet’s aquarium a natural look and feel.

Alternatively, if you have the facility to grow your own plants, you can add some vegetation to your crayfish tank and replace the plants every few weeks. That’s actually quite important, as the crayfish inhabits waterways that are usually densely vegetated.

Tank size

If you decide to take on a Blue crayfish, you’ll need to house them in a tank of at least 20 gallons for one specimen. More than one crayfish should be kept in an aquarium of 30 gallons or more, and the animals should be of different genders and the same size. That’s crucial, as a larger crayfish will most likely attack and eat a smaller one.

Although the Electric Blue crayfish is mostly a bottom-dweller, they are extremely good climbers, so you must use a tank with a tightly fitting lid to prevent escape attempts. If a crayfish does get out of the tank, it won’t survive for more than a few hours out of water.

Water parameters

Blue crayfish are pretty tolerant of pH levels as long as they remain stable, ideally between 7.0 and 8.0, although the closer to the neutral 7.0 is most beneficial for them. Make sure that the pH level doesn’t drop below 7.0 for any length of time, as that can cause problems with molting. Water carbonate hardness should be between 4 and 6, and the general hardness between 6 and 8 GH.

Keeping the temperature stable is very important for Blue crayfish, ideally between 68° and 75° Fahrenheit. If you need to use a heater to achieve that temperature range, be sure to place it out of reach or inside a protective casing so that the crayfish cannot move or damage the unit with their claws.

Never add Blue crayfish to a tank that hasn’t been fully cycled. Ideally, levels of ammonia, nitrite, and nitrate should be as close to zero as possible. Also, be sure to add dechlorinator to tap water that you add to the tank or use distilled water.

Filtration

Blue crayfish need well-oxygenated, clean water to thrive. So, you’ll need to install an efficient filtration system with a sponge cover to protect the unit from the crayfish. That’s essential if you intend to keep a male and female crayfish in the same tank, because if the crayfish breed, baby crays can easily be sucked into the filter system and lost. Also, the crayfishes’ claws will rip a sponge filter to shreds. Overall, the easiest way to avoid that is by choosing an external HOB filter or a canister system.

Electric Blue crayfish may drown if the water in their aquarium doesn’t contain sufficient oxygen. So, we recommend that you use an air bubbler or place a rock in the habitat that is proud of the water, providing the crayfish with a safe means of getting out of the water if necessary.

Tank decorations

Blue crayfish are confirmed borrowers, so you’ll need to use a sandy or fine gravel substrate in their tank to facilitate that natural behavior.

Chameleon crayfish!

Interestingly, these remarkable creatures can change their coloration as a means of camouflaging themselves, depending on their environment. That’s an important survival technique, as crayfish live in habitats where they can be preyed upon by multiple different creatures. So, if you want to bring out the most vivid blue color in your pets, we recommend that you use a blue substrate.

Hiding places

Crayfish like plenty of places to hide during the daytime, so you should provide these in the form of resin caves, pieces of PVC pipe, driftwood, rocks, and artificial plants. If you intend to keep several Blue crayfish, be sure to provide hiding places in different areas of the tank so that each one can mark out its own territory.

Unfortunately, crayfish have their own ideas on how they like their environment to look, and you should expect your pets to rearrange things to suit themselves. Any items of decoration that are lightweight are almost certain to be moved by the crayfish, and any live plants will most likely be chopped up and eaten.

Blue Crayfish

Tankmates

As previously mentioned, it’s best to keep Electric Blue crayfish either alone or with others of their own kind in a very large tank with lots of hiding places. However, with some careful thought, it may be possible to keep some other fish too.

Avoid large, aggressive fish species such as cichlids that may attack the crayfish and view them as a food source. However, smaller, slow-moving fish may become lunch for the crayfish. If you have a very large tank, Red Tail sharks may make suitable tankmates. Other fish that can do well with crayfish include:

Basically, any fish that are fast-moving and spend their time swimming in open water in the upper and middle areas of the water column should be able to avoid the crayfish and may, therefore, make suitable tankmates.

Shrimp and snails don’t generally make a good choice of tankmates for crayfish. Crayfish tend to grab anything that crawls past them on the tank bottom, and both the aforementioned creatures will be living right in the danger zone.

Breeding Procambarus alleni

If you provide them with a large tank and the correct conditions, your Blue crayfish will readily breed in captivity.

Crayfish become sexually mature and able to breed when they reach around an inch in length. Mating behavior involves the male climbing onto the female’s back and grabbing onto her with his claws. Keep an eye on the crayfish during mating, as they can become very aggressive toward each other after the event, and you may need to intervene.

Eggs and babies

The female crayfish carries her eggs underneath her tail, and the correct term for that is “berrying.” The number of eggs produced depends on the size of the crayfish and the suitability of the environment in which she is kept, and numbers can range from 50 to several hundred eggs.

When you see the eggs, remove the female crayfish a place her in a separate 10-gallon tank or larger. The eggs generally hatch within 20 to 30 days. Once the baby crayfish emerge, for the first few days, they are carried on the female crayfish’s back or under her tail. Throughout that time, the mother crayfish secretes “maternal pheromones” that tell the youngsters to stay close to her so that she can protect them from predators. However, once those pheromones wear off, the baby crayfish leave their mother and get as far away from her as possible, as there is a very real risk that she will eat them.

So, when you see the babies leaving their mother, you should remove her from the tank. In turn, once the young crayfish are large enough, they should be separated and moved to larger tanks to avoid the risk of cannibalization. Make sure that these nursery tanks contain plenty of hiding places and heavy planting so that the juvenile crayfish have the best chance of survival.

In summary

Electric Blue crayfish can make a fascinating and novel choice of pet, and they’re arguably much more interesting to watch than most fish species. Crayfish are hardy and tolerant of a wide range of water parameters, making them pretty straightforward to care for.

However, you will need a sizeable tank if you want to keep crayfish, and they are aggressive and destructive, making them tricky to keep in a planted or community setup.

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