Electric Blue Crayfish

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Rebby

Aquarium Advice Newbie
Joined
Oct 27, 2022
Messages
9
Location
Norfolk
Hey there,


I've been looking into care and ownership of the electric blue crayfish. I love them. But was interested in people's opinions who have kept them before. Have people kept them in community tanks e.g. with fish? I know it says it's best not to online but there's varying opinions. Any tips and advice would be great. Also how big do they really get? Online it says 4-6inches but people have said they get much bigger whose correct?

Big thanks in advance !
 
Hi! Crawfish are so much fun! I've had electric blue and other types, and they are endlessly entertaining.

To get straight to your questions: anything you put in the tank with them becomes fair game for a meal. Snails and shrimp~delicious. Fish~only the fastest top-swimmers stand a slight chance of surviving.

They grow to be 4-6 inches. Other varieties can be slightly smaller or larger, but that's the median size. Every time they go through a molt they come out a little bigger.

The blues are very aggressive. I bought 12 small goldfish for my first electric blue. They were meant as company and eventually food and they fulfilled those assignments perfectly. Every time he needed some extra protein beyond the basic feedings he'd hunt down and gobble a fish.

I made the mistake of putting a mystery snail in with him, a large fellow that I liked. Those beady little black eyes followed him around but nothing happened for a month. I figured the snail was too big or maybe crayfish don't eat snails. Wrong. I was actually standing there looking in the tank when he charged out, headlocked the snail, and proceeded to punch its lights out. He actually repeated punched the snail with his other claw, like they were in a movie bar fight or something. Then he ate the snail in one big slurp. Still sickens me to think about it. That's how I learned to not put anyone in with a crayfish.

Look up my name on this site for many posts I've made about having crays. Lots of info about type of tank, substrate, feeding, molting, plants and decor. If you have more questions, I and other crayfish lovers here will be glad to answer you.
 
Hiya there ADsnail,


Thankyou for your wonderful reply. I will certainly look up your posts and get some more info into crays before I go and buy one. Even though it's so hard to restrain myself. Lobsters and crays are one of my favourites. If only people could see my house ����

I currently have a 240l fluval Roma tank. I have various dragon-stone and driftwood features as well as live plants and some decorations so would probably need to rejig it all.
I have zebra danios, cherry barbs, honey gourami, black neon tetra and scissortails in there ATM so don't know how they'd fair.
If I got a young electric blue crayfish I was thinking they are quite small so would be a while before it would be catching fish ? Suppose it depends how long it takes for them to grow.


Big thanks
 
They really need their own tank. You'll see, they are the star and everything revolves around them. From the sand at the bottom for their constant digging (they live to dig!) to the plastic plants they can't eat (but tumble around in for fun) to the decor especially placed to be hideout caves for these little pirates.

Even if you get a very young electric blue, like 1 inch, your fish may get a stay of execution for awhile but the end is inevitable. Baby crays molt every 6-8 weeks (possibly a little more often depending on the individual) and each time they're a little bigger, a little more aggressive. This will continue until adulthood, when the molting slows to 1-2 x per year. Meanwhile, they are ravenous before they disappear for a molt, and ravenous afterward. They are very crafty hunters and will lay in wait for a fish until it's literally within his claws/jaws.

But there's always one way to find out...put him in with fish and see what happens. Personally, I'd name all my fish "Dinner":popcorn:
 
I agree with the others. Crayfish/ crawfish do best in tanks without fish to eat. They are nocturnal scavengers/ predators and will wander around the tank at night and eat anything organic. They do best when fed a varied diet including some plant matter (live aquarium plants).

Do big regular water changes, gravel clean the substrate and keep the filter clean.

Have the pH around 7.0, the GH should be around 100-300ppm so there are some minerals in the water for them to build their shells.

Have a cover on the tank because they climb out and wander around the house. I used to find mine in the bathroom or behind the fridge. Mum and my sisters were never too happy when they found them in the bathroom. :)

You could get shrimp to go in your tank with the fish. They aren't as colourful but most won't eat the fish or plants. If you want a crayfish, set up a species only tank and get a pr.
 
Thanks for all the advice.

I have been having a real good look into all the different crays that can be kept in aquariums, care and requirements today.
I do like shrimp and there are some beautiful varieties but I really love crays and lobsters.
Only snag I've hit now is that (and I'm not sure if this is an international forum) but I'm in the UK and apparently there are bans and restrictions on owning most crays, including the electric blue and CPO apparently only Cherax quadracinatus is legal !!!! I had no idea !!
Especially as I've been into independent stores where they have seen them being sold !! Is this correct ?
 
Im from UK. There are all sorts of bans on aquarium livestock, and some are more strictly enforced than others. Not that im suggesting you go out and break the law, but go to a good fish store and see what they have. Ive seen some pretty big crustaceans in Pets at Home too.

Whereabouts are you?

Glofish are banned here, and you wont see them for sale.

Mystery snails and apple snails are also banned. You won't find Mystery snails for sale in stores, but apple snails are very commonly found.
 
I'm from East Anglia Area.
I've not spent much time in pets at home but there are a few established aquatics shops and new ones opened (last few years) near me where I have seen electric blue crays.
And there advertised for sale on UK online Aquatic stores too so wasn't sure.
 
Only snag I've hit now is that (and I'm not sure if this is an international forum) but I'm in the UK and apparently there are bans and restrictions on owning most crays, including the electric blue and CPO apparently only Cherax quadricarinatus is legal !!!! I had no idea !!

we eat them here :)

If you want freshwater crayfish, move to Australia. We have a bunch of species including 3 of the biggest in the world.

The giant Tasmanian cray (Astacopsis gouldi) will bite your leg off if it grabs you. These things don't fit in a normal cooking pot and can grow to nearly 3ft long.

Murray River crayfish (Euastacus armatus), which hits a foot and a half long.

Hairy marron (Cherax tenuimanus), which was around when dinosaurs were. These guys were only found around the start of this century and have hairs over their shells.

Smooth marron (Cherax cainii), which has been spread all over the southern half of the state and is normally black or dark brown in colour. However, back in the late 1980s, a farmer found a blue one and developed the blue marron, which is the most brilliant blue colour. These marron can reach 18-24 inches long, but are normally found around 12 inches long.

See the following link for more info. We also have dozens of other species of freshwater crayfish, but the ones listed above are the biggest in the world. Also very tasty :)
https://rivers.dwer.wa.gov.au/species/cherax-cainii/
 
I'm from East Anglia Area.
I've not spent much time in pets at home but there are a few established aquatics shops and new ones opened (last few years) near me where I have seen electric blue crays.
And there advertised for sale on UK online Aquatic stores too so wasn't sure.

I've found that wherever they're sold, the stock comes and goes. Meaning, if I'm looking and find any for sale in a shop I jump on it because once they're gone it could be - weeks? Months? Never again depending on several factors? Seems I can't find a steady supply of them. You sound enthused, so it might be good to get your setup all set up so when you find your new cray, you'll be ready.
 
Hey ADsnail,

Yes I am fully enthused !!! That's my plan this weekend to just rejig my tanks and get it ready just in case. Few aquatics centres I'm going to check out this weekend also to put feelers out.
So exciting !!! Big thanks for your advice and help.
Been researching there food etc.
I know they eat almost anything. And you buy the wafers but seen videos of people putting peas in tank and egg shells too. Are these good ?
Can you use any eggshells if so?
 
I can't see any real nutritional value in egg shells. If you want to try that is fine but boil the shell first so there is nothing bad on it. And check with your egg supplier. Some companies spray the eggs with a chemical to stop them developing bacteria from the chook poop. Other companies just wash them.

You can try them on various vegetables (green leafy, peas, pumpkin, zucchini), but no onion or onion relatives, and no potatoe.
 
I'll bare that in mind. Just saw that some people had eggshells in the tank so assumed there were good. I guessed it was to do with the calcium that they need?

Thanks for reply
 
Egg shells might provide some calcium but if you have water with a GH (general hardness) of 150-300ppm, there should be plenty of calcium in that for them and they won't need calcium supplements.

Some people add cuttlebone skeleton to the tank for snails to chew on. Crayfish might eat that as well and it should be safer because it is from the beach rather than a battery farm.
 
Hey ADsnail,

Yes I am fully enthused !!! That's my plan this weekend to just rejig my tanks and get it ready just in case. Few aquatics centres I'm going to check out this weekend also to put feelers out.
So exciting !!! Big thanks for your advice and help.
Been researching there food etc.
I know they eat almost anything. And you buy the wafers but seen videos of people putting peas in tank and egg shells too. Are these good ?
Can you use any eggshells if so?

They do need calcium but not egg shells. Here's the food breakdown:

-A basic building block is crustacean food, like Hikari Crab Cuisine. That's the Cadillac of these foods but there are other brands if you can't find that. Look at Hikari's ingredients online and compare them with whatever brand you choose. This contains calcium as well as other shell building ingredients. One thing you don't want to see is copper. If that's on the list, don't buy the product. Copper kills crustaceans. Just a tiny bit 2-3 times per week depending on how much other stuff he's eating, whether he's just molted and needs extra calcium, or you're feeling lazy and just want to throw something quick in there on a busy day. It's a supplement, but an important one.

-Frozen peas and carrots. A pea every day or every other day depending on how quickly he snatches it and drags it into his lair, meaning he's hungry. A little carrot cube every once in awhile for variety; they don't love these as much. Defrost in your fingers under running water. The pea must be squeezed so it pops out of the outer skin so he can access it. It will sink to the bottom. It's good to drop this right in front of him because he comes running and drags it into his lair. Fun.

-Frozen shrimp. Just 1/3 or 1/2 depending upon how big it is. Defrost under running water in your fingers. Once or twice a week depending on how much he's eating. He'll want it all before and after a molt. Great calcium and protein.

-Algae tablets. Very important nutrients and they love them. It's another thing you can toss in when you don't have time. I feed 2 times a week. Watch when you drop it in front of him - they eat it like a cookie, turning it round and round and nibbling the edges. Ugh, they are just so adorable.

-Fresh veggies. There's a wide variety to experiment with but I usually do zucchini or cucumber. Both do contain some calcium. Other things like broccoli and onion become too stinky if they don't eat it all. So, how to do the veggie? Slice and blanch. Blanching is boiling for one minute to break down the outer fibers and make it accessible (snails adore blanched veggies too - they need a day to let it get good and old before they chow down). Blanching is quick and easy. Slice veg 1/8-1/4 inch and place into a small amount of water (like 1 inch) in a small pot. Boil one minute. Let it cool. That's it. *Note about sliced vegetables: they tend to float and you want to keep it on the bottom, so skewer it with a chopstick and press down so the stick is into substrate. I have many videos of crayfish working at prying zucchini slices off chopsticks. It's hilarious. My friends are totally over it. *Note: leave the chopstick. He'll play with it for days. I once actually found my Cherax Thunderbolt using a chopstick as a leverage device to lift something heavy in the tank for his digging. That is scary intelligent. I wonder if he could do my taxes.

-The exoskeleton. When your cray disappears for a day or two he's probably molting. For babies this would be approx every 6-8 weeks; it slows down as they get older and becomes 1-2 x per year as adults. Each time, they back out of the old shell and the claws are last to go. Leave the exoskeleton. They need to eat it for the best possible calcium and nutrients. They are very hungry before and after a molt and need extra calcium and protein. *One way to tell if they're hungry is if you see him standing on his hind legs reaching up trying to get your attention when you walk by. No, he's not saying hello. He's saying "feed me, you giant!"

There's a concern among some that they drag and bury their food, allowing rot and making a dirty tank. In my experience, yes, they do drag and bury food but they always find and eat it later. They do like a bit of rot. There's a fine line about how much is too much; the key is to watch his eating patterns and feed accordingly so he does dig up his stash and eat it. One way you'll know how you're doing is by the occasional vacuuming: if you don't find any chunks and it doesn't smell bad in there, you're feeding the right amount.
 
Make sure any shrimp you put in the tank is cooked to kill off anything they might have. Shimp and fish can carry microsporidian infections and it survives freezing so you need to cook it before putting it in a tank with other crustaceans.

Shrimp or fish with a microsporidian infection develop cream/ white muscle tissue under the skin. It is spread via eating the contaminated flesh.

-------------------

I have never had crustaceans bury food. They will grab big pieces and drag it back to their cave to eat but they should eat it all straight away (within 10-15 minutes. If they aren't eating it all straight away, you are feeding them too much.
 
Rebby, I've never cooked shrimp and neither have the several people I know who keep crays. One has an over a dozen tanks of them and has kept them for 40 years. The other is my neighbor/mentor, who's kept them since the 50s. Are we all just massively lucky for decades? You can cook it if you want and they will eat it, but if you're not into cooking meals for him...just saying, none of us are having a problem while we are giving our little fellows the shrimp they love.

Crayfish bury food. It's what they do. It's like digging. In fact, it's part of digging. Crustaceans, especially bottom feeder crayfish, like things to get a bit old so they can savor it more.

So there you go. It's good to make your own decision based upon which facts seem to resonate best with you.
 
I love cherax's. They're bigger than Clarkii's. If you really want a blue one then no problem, I've seen blue and purple Cherax's.
 
I think they ordered this from Thailand
 

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