Common Name: Blue Crayfish (often mislabeled as Blue Lobster)
Latin Name: Procambarus alleni
Origin: United States
Ease Of Keeping: Easy, but….
Adult Size: 6 to 7 inches (19cm)
Minimum Tank Size: 20gal
Feeding: just about anything they can get their claws on
Spawning Method: egglayer, female carries eggs under her carapace
Comments: The Blue Crayfish is a wonderful addition to any tank, so long as one keeps an eye on it. The only requirements for them in a tank is a cave to hide in during the day, and plenty of plants to climb and hide in. Proper aeration is necessary, as is filtration. They have a reputation for being vicious killers, but as far as I’ve found, the trick is to just watch what you put in there with them. They are very hardy creatures, and they can survive in almost any element. I will lay out some specifics here, to help you keep your crayfish happy and healthy.
When it comes to feeding, I’d say your best bet when your crayfish is young would be to start off with some shrimp pellets, but be sure to compliment them with some algae pellets or a slice of zucchini to get some roughage for them, and because it will distract them from devouring any live plants you have in your tank (I learned THAT the hard way). All crustaceans are essentially bottom feeders, so they will really eat just about anything. Crayfish do have a fairly voracious appetite, but make sure you don’t overfeed (see MOLTING, below).
Territory is VERY important to Crayfish. You really only want to put one in your tank. If your tank is over 50 Gal, you can probably get away with two, so long as they had very definite territories, each with their own cave to hide in, as spaced out as possible. But keep an eye on them, and don’t be surprised if one is clawless after a while; when they fight, they don’t always kill, they usually fight for dominance by ripping their opponent’s claws off. On the upside, single crayfish really don’t need much in the way of space, so long as they’re fed. Just enough so they can roam around a big, and a plant to climb on. I’d recommend putting like two or three feeder fish in with it, such as rosie reds, just in case the Crayfish needs some fresh meat.
Which brings me to my other topic. As far as getting along with other fish, well….I’ve been told Crayfish will eat everything in your tank that they can get their hands on. This isn’t exactly true, but it’s close. I keep mine fairly well fed (I stash a pellet in his cave every other day, and he’s happy), and he only kills other fish if they try to eat his food. As mentioned above, crayfish are bottom feeders, so make sure anything you put in is a middle- or top-feeder. But crayfish also love to climb plants, so middle feeders aren’t completely immune. Plecos are safe around crays because they have armored plating along their back, so tough-scaled fish work well. The other thing to look out for is speed. I have a baby bala shark in my tank (inch and a half…he’s so cute), and he darts around the cray WAY faster than he can catch him. Same with my black skirt tetras.
Mating And Sexing
If you choose to mate your crayfish, you need patience. To tell the difference between male and female, simply pick them up. To do this safely, catch them in your net, and then place your thumb and index finger on either side of the body right behind the claws, and pinch GENTLY. This will not hurt the crayfish (they’re very well armored), and will prevent you from getting nipped. And don’t worry, like most crustaceans, Crayfish can stay out of water for short periods of time as long as they remain damp.
Now, hold them upside down and look underneath their tail. Right behind their last pair of legs, males of the species will have two tiny appendages that look like miniature legs. If these are not present, then you have a female.
One thing to look out for is their molting cycle. Molting is natural and healthy for them; it means they’re growing. However, if you overfeed your crayfish, and the water is TOO warm (78 to 80 degrees or so), they will molt faster, and that will shorten their lifespan. In nature, crayfish come from lakes and rivers, which tend to be cold a lot of the time.
If raised right, your Crayfish will most likely wind up being your favorite tank denizen. I know mine is my favorite. Though, admittedly he’s a bit of a bastard to the other fish. He delights in chasing them away and claiming multiple areas of the territory as “his”. In fact, before typing this, I had tossed two algae tablets on either side of the tank…one into his cave just for him, and one on the far side of the tank for the other fish. While writing this, I watched him devour most of his tablet, then race to the other side, scare the fish away, and drag their tablet away to his cave for later dining. He’s funny like that.
No matter what you do, I hope you truly enjoy your Blue Crayfish. Good luck!
Comments: First of all I would like to say great job on this webpage, very well organized. I got my blue crayfish about a month ago and he is so cute. But I will addmit he can be a pain somtimes, when I brought home my angelfish and my 3 kissing gouramis within a week they had all dissapeared I finally figured it out when I cought him eating 1 of my kissing gouramis. Other than that hes one of my favorite aquarium residents that I have ever had. So I guess it just matters what you mix with them.
But he is so funny… this morning I found hanging from one of my floating plants to get the floating pellet. Image
I think these little guys make great pets.
Comments: Its a very nice webpage. I also agree that blue crayfish are very cute. However, ours has killed well over 10 fish. Mostly gouramis, so we switched him to a new tank with cichlids. However, he killed three in a matter of a day. I recommend getting a crayfish and putting him in his own tank because ours did not mix well with any other fish except sharks. They’re a great addition… but don’t be suprised if your population in your tank decreases.