Although crayfish are considered low-maintenance pets, low-maintenance doesn’t mean no-maintenance. These freshwater crustaceans need ample space, suitable tankmates, and a varied diet to truly thrive. However, there are many aspects of their care that first-timers overlook. Here are some common mistakes that new crayfish owners make and how you can avoid them.
1. Choosing Unsuitable Tankmates Like Bottom Feeders
Don’t let the name “crayfish” fool you; crayfish can’t swim in the same way that their finned counterparts do. While they can propel themselves backward using something called the “caridoid escape reaction” (a defense mechanism found in lobsters, krill, and shrimp), they spend most of their time scuttling along the aquarium floor. They’ll spend most of their time digging holes in the substrate, eating decomposing matter, and hiding under cover. They’ll also attempt to capture any fish that dares swim too close, like bottom-dwelling fish.
There’s no denying that bottom-feeders make great additions to aquariums. Yet, because of crayfish’s natural aggression, they’re not suitable tankmates. Some bottom-feeders that wouldn’t fare well with crayfish include cory catfish, pleco, and loaches. If you want a multi-species aquarium that includes crayfish, consider top-dwelling fish, like tetra, betta fish, and goldfish. They won’t interact with the crayfish on the tank’s bottom and will remain free of those treacherous claws. Crayfish are also suitable for aquariums with fast-swimming fish, including danio and rasbora.
2. Keeping More Than One Crayfish
Crayfish, like many crustaceans, live solitary lives, only coming together seasonally to mate in the late summer and fall. They do not have complex social needs, and they won’t feel “lonely” if they’re by themselves. In fact, many prefer life that way because crayfish are extremely aggressive and territorial creatures. Ecotoxicology and Environmental Safety studied the behaviors of male and female crayfish. It noted that while neither were particularly social, male crayfish were overwhelmingly more aggressive.
Fighting is common in aquariums with multiple crayfish that don’t have enough space to claim as their own. If neither crayfish submits to the other, they will literally fight to the death, using their claws to dismember their rival piece by piece. Claw size is not an indicator of how aggressive or strong a crawfish is, according to a study published by Animal Behaviour. Instead, carapace size plays a much larger role in asserting dominance. In any case, avoid housing multiple crayfish if possible. While some may have individual temperament conducive to co-existing with other crayfish, there’s no way to predict this upon setting up a freshwater aquarium.
3. Overfeeding Their Crayfish, Affecting Water Quality
Many retailers sell pet crayfish as adults that must be fed about four times weekly. Crayfish enjoy a varied diet, which can range from frozen peas to shrimp flesh. There are also sinking nutrient pellets packed with the vitamins and minerals crayfish need to thrive. Some aquarists make the mistake of thinking they must feed their crayfish every day, but this is where good intentions can go wrong. Unlike some fish that are voracious eaters (like koi and goldfish), crayfish only eat a modest amount. Uneaten food can also decompose quickly and cause a spike in ammonia, throwing off the aquarium’s water parameters and risking the fish’s health. It may also cause algae blooms.
Crayfish are recommended for first-time aquarium keepers because they’re so hardy and can survive in different water conditions. However, nobody wants a smelly, green-watered aquarium in the living room. If you get or have a crayfish, stick to a schedule that allows your pet to anticipate when it will be fed. If you drop a sinking pellet once every other day at 4pm, it will learn to expect that. Crayfish are smarter than most people think!
4. Not Recognizing the Signs of Ill Crayfish Health
You really have to go above and beyond to kill a crayfish. In the wild, these hard-shelled critters can live in drainpipes, garbage-filled culverts, and shallow puddles that dry under the sun. They don’t need strict water parameters like some aquatic pets (like axolotls), and they can withstand fluctuations in water chemistry even if the tank crashes. Some aquarists note that in their years of keeping crayfish, most die due to complications while molting as opposed to disease.
Still, it’s important to note the signs of illness in your crayfish, so you can act accordingly and address the issue’s root cause. As noted, crayfish are hardy pets. If the crawfish in your aquarium gets sick, chances are, so are its tankmates. That said, signs of ill health in crayfish include:
- Open wounds
- Lethargy
- Being non-responsive to touch
- Loss of appetite
- Disinterest in normal activities (like digging holes)
- Erratic movement
- Cloudy eyes
If you suspect illness in your crayfish, remove it from the aquarium and put it in a small back-up tank. This keeps it safe from curious tankmates and may promote its chance of recovery.
5. Misjudging the Commitment Needed
If you’re looking to dip your toes into the waters of aquarium-keeping, you should consider starting with beginner fish that live relatively short lives. That way, if the hobby isn’t up your alley, you can cut your losses without having made a giant commitment. Live-bearing fish, such as mollies, guppies, and swordtails, generally live three to five years. Betta fish also only live about two to five years.
Crayfish enjoy about the same longevity, averaging about five to six years with the proper care. During the animal’s lifespan, you’ll be responsible for its habitat’s maintenance, water changes, and cleanings. You must also provide ample enrichment (such as live aquarium plants and hiding places) to give your crayfish a good quality of life.
If caring for a pet crayfish seems like a lot right now, reconsider whether freshwater aquarium-keeping is a wise decision. If you’re still up for the task, then you’re in luck! Crayfish make great pets. They are lively and entertaining, and offer a bit of spice to any home aquarium.
