Keeping crayfish happy?

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zeezz

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I have a small population of burrowing crayfish living in my yard in and around a small spring. They spend most of their time in tiny holes they dig down to the water table. When it rains hard, a small stream flows and they come out and swim around. Then it all dries up and you would never think there is anything living in there! They are small, big ones are about 4.5", lot of them closer to 1.5". Also hundreds of little babies around, they must have recently hatched.

I want to build a larger pond with year round water and a bigger crayfish population. I caught about 10 bigger ones and I would like to keep them in tanks this fall/winter instead of letting them go hibernate. Hoping to breed them somewhat selectively and grow them up big before putting them back into the pond because there are a LOT of predators.

My question is, do I need to keep them "happy"? That is, they are digger crayfish, they like to dig mud tunnels. They seem perfectly happy in a bucket of water, except they keep trying to dig a hole in it. One in a styrofoam cooler made a hole straight through! I put a bunch of native rocks and plants in with them, but they still want to dig their way out. Do I need to give them a deep sandy bottom to dig in? Does a crayfish need to be "happy"? (Hey, at least I'm not boiling 'em!) Would they be happy enough in a simple dark tank with clean/aerated water, food, and a place to hide?

Right now they have plenty of places to hide, several different pipes, rocks, etc and I only keep 1 per tank, so they are safe, but they keep trying to dig through plastic. Eventually I'll move them into larger tanks that can handle more than one.
 
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Fae

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zeezz said:
I have a small population of burrowing crayfish living in my yard in and around a small spring. They spend most of their time in tiny holes they dig down to the water table. When it rains hard, a small stream flows and they come out and swim around. Then it all dries up and you would never think there is anything living in there! They are small, big ones are about 4.5", lot of them closer to 1.5". Also hundreds of little babies around, they must have recently hatched.

I want to build a larger pond with year round water and a bigger crayfish population. I caught about 10 bigger ones and I would like to keep them in tanks this fall/winter instead of letting them go hibernate. Hoping to breed them somewhat selectively and grow them up big before putting them back into the pond because there are a LOT of predators.

My question is, do I need to keep them "happy"? That is, they are digger crayfish, they like to dig mud tunnels. They seem perfectly happy in a bucket of water, except they keep trying to dig a hole in it. One in a styrofoam cooler made a hole straight through! I put a bunch of native rocks and plants in with them, but they still want to dig their way out. Do I need to give them a deep sandy bottom to dig in? Does a crayfish need to be "happy"? (Hey, at least I'm not boiling 'em!) Would they be happy enough in a simple dark tank with clean/aerated water, food, and a place to hide?

Right now they have plenty of places to hide, several different pipes, rocks, etc and I only keep 1 per tank, so they are safe, but they keep trying to dig through plastic. Eventually I'll move them into larger tanks that can handle more than one.
Why not leave them outside over winter? They survived this long, they will likely survive one more winter ;)

I would make sure you have everything set up before you embark on your cray-mish, such as the larger pond, or even the bigger tanks.

But if you're determined to keep them now, I recommend taking the bigger ones back. They are hardy, set in their ways, and probably going to survive just fine over winter. They're also less attractive to predators (big pinchers!). What I would do is collect as many tiny babies as you'd like, and raise those over the winter. They are far less likely to survive, statistically, and by raising them by hand as you will be, they will be much bigger than their brothers and sisters by spring time. Also, you likely won't have significant losses, whereas in the wild it's possible NONE would survive.

I'm not sure on the specifics for your type of crayfish, but I have been raising signal crayfish babies, which are native to my area. They grow slowly. By the time they are 2 inches long, they will be 3 or 4+ years old. The big ones are more like 14 years old. And the bigger the crayfish is, the better the chance it has of surviving.

You said your crayfish burrow. Seems like an obvious solution to your problem is to add sand or mud. You can use sterilized aquarium sand or just scoop some out of the area where you catch them.

For my crayfish, I have them in a 10g tank filled about halfway. It's outside. There's a HOB filter. There's about 2 inches or less of sand, lots of rocks stacked to provide hides, moss, aquatic plants, algae, and lots of duckweed. Signal crayfish burrow in the sand under rocks, but the rocks are the key thing they're after.

They are very happy in this, and have molted serveral times. There's two of them, I got them as babies off their mom accidentally in I think it was June. I had them in this tank with a bunch of tadpoles, the tadpoles I had for about a month or two prior so a good population of bacteria and infusoria had already built up for them to eat. I also feed them bloodworms and brine shrimp, and id imagine they eat all the larvae and algae and whatnot as well.

I'd say I'd be able to fit comfortably another 3 or so crayfish before they started fighting, but I actually have no idea practically what the limit is. I've seen them team up together to try to escape once, so I'm not sure if they would even fight at all.

My point to all my rambling anecdotes here, is that baby crayfish would be the easiest and most productive choice to raise, and you could easily fit 5+ per 10g tank (adjust for your size tank accordingly). However, I strongly recommend you add some kind of substrate they can burrow in, especially if they're going back outside later.
 
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zeezz

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One of the reasons I'm catching them now is I'm not really sure what will happen as fall comes. I don't know much about them and there isn't a ton of information available about these "digger" crayfish. I've been watching them all summer and it is amazing how they spend weeks in nothing but a wet tunnel between rains. The only way to catch them is to put out traps when the water flows. I may not be able to catch them at all in winter, really not sure. (Summer is our rainy season) I'm thinking I may be able to get them to mate indoors during the winter to have a better supply of the babies in the spring. In the wild I think they only have babies at the end of summer. (could be totally wrong)

Another reason I'm catching them is I'm literally trying to study them, I'm measuring and counting them, and putting a silver sharpie mark on every one I throw back to see if I catch it again. Looking for some of the best examples to become moms.

I'll be working on expanding the pond over the next few months. At least want to keep one or two as "pets" for now.

From what I can tell these have a shorter life, only about 3-4 years...I'm guessing the larger ones are closer to 3-4 years old. Also curious if they can get bigger/older in captivity. They absolutely HATE each other - if you put two in a 5 gallon bucket they instantly try to fight. I found several with only one claw from battle.

I am trying to keep some of the babies but I've had a few die and I can't figure out why/what I'm doing wrong. They are definitely fun to watch. I'm kinda worried if I catch too many and kill them all it could have a big effect on the population. It's a pretty small spring/ditch they are living in. (although only about 600 feet from a lake)

I'd prefer not to have sand/mud in their tank just to keep things cleaner. I don't know if they are just trying to escape as crayfish do, or if they are going nuts trying to dig tunnels. I don't want to be cruel to them, but it is sort of a "farm". Some gravel is fine, but they can't really make a "tunnel" in that.

Is there something besides basic plant material that I could put in the tank and let them rip up? Maybe some half rotten wood or something? Just something to keep them busy.

I did put some of the native sand in with the babies but it makes the water murky and really hard to see the crayfish as they are the exact same color...
 
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Fae

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zeezz said:
One of the reasons I'm catching them now is I'm not really sure what will happen as fall comes. I don't know much about them and there isn't a ton of information available about these "digger" crayfish. I've been watching them all summer and it is amazing how they spend weeks in nothing but a wet tunnel between rains. The only way to catch them is to put out traps when the water flows. I may not be able to catch them at all in winter, really not sure. (Summer is our rainy season) I'm thinking I may be able to get them to mate indoors during the winter to have a better supply of the babies in the spring. In the wild I think they only have babies at the end of summer. (could be totally wrong)

Another reason I'm catching them is I'm literally trying to study them, I'm measuring and counting them, and putting a silver sharpie mark on every one I throw back to see if I catch it again. Looking for some of the best examples to become moms.

I'll be working on expanding the pond over the next few months. At least want to keep one or two as "pets" for now.

From what I can tell these have a shorter life, only about 3-4 years...I'm guessing the larger ones are closer to 3-4 years old. Also curious if they can get bigger/older in captivity. They absolutely HATE each other - if you put two in a 5 gallon bucket they instantly try to fight. I found several with only one claw from battle.

I am trying to keep some of the babies but I've had a few die and I can't figure out why/what I'm doing wrong. They are definitely fun to watch. I'm kinda worried if I catch too many and kill them all it could have a big effect on the population. It's a pretty small spring/ditch they are living in. (although only about 600 feet from a lake)

I'd prefer not to have sand/mud in their tank just to keep things cleaner. I don't know if they are just trying to escape as crayfish do, or if they are going nuts trying to dig tunnels. I don't want to be cruel to them, but it is sort of a "farm". Some gravel is fine, but they can't really make a "tunnel" in that.

Is there something besides basic plant material that I could put in the tank and let them rip up? Maybe some half rotten wood or something? Just something to keep them busy.

I did put some of the native sand in with the babies but it makes the water murky and really hard to see the crayfish as they are the exact same color...
Sorry I'm just responding to this now! I'll try to address your queries, hopefully you're still interested

Are you from north America? And are you certain there isn't much info on these crayfish? I know the digger crays I'm familiar with have a wealth on info available because they've been extensively aquacultured, but perhaps you need to use their scientific name to google?

If these crays are the same as signal crays, they would carry their eggs on the bottom of the tail, which would also hatch and hang there as babies for a few weeks. How I got my babies was accidentally taking home a mama to eat and subsequently being horrified at my almost infanticide. I returned the mama and most of her babies lol. That was in the spring, but my climate is likely much different so probably yours have babies at other times. The babies are verrryyyy small, like 1-2cm if that when they're hanging on mom. Mine are about 5 months old maybe? And they're only about 1.5in long now. Likely they'd be smaller in the wild as I feed mine very well.

Since crayfish molt to grow bigger, they are very slow growers. It's very incremental. The average lifespan of signal crays that make it to adulthood is 12-14 years, and as many as 20 years but that's rare in the wild. Might be different for yours, especially if youre from a warm climate.

Crays actually don't hate eachother, but they are territorial. Especially in a place like you describe yours as coming from, good territory is probably hard to come by thus worth defending. When you put two in a small bucket (floor space means way more than height to them), they will naturally fight because they can't get away from each other. Their claws will grow back slowly over time, but the best way to avoid fighting is to provide at least as many hides as you have crayfish. That way they can claim their own territory.

Make sure these crays can live in ponds- you might end up destroying prime habitat they've adapted for. They likely overwinter in the mud, which keeps them from freezing.

If you want to be able to see the crays, I suggest you use sand anyway, but rinse it clear. Native sand or any sand is fine, you can buy white aquarium sand if you want the contrast to make them more visible. They will be incredibly stressed and more likely to kill each other, and definitely won't mate without it. Imagine someone captured you, took your clothes away, and put you in an empty glass box with a couple other humans you don't like who are also naked. You'd probably be really stressed, they feel the same without sand to hide in.

Half rotten wood will foul your water. Research what they eat, and find that. Likely they eat algae and detritus and plant matter. I would set up their tank like this:
Depending on size, no more than 1 adult cray per 5-10g
6 inches of rinsed sand
Find river driftwood- that is, sun-dried driftwood, it will be light and white. Boil that for a couple hours, or until it sinks. This will be pathogen free. Add to tank
Rocks, stacked on each other a little but not covering the tank
Moss on some rocks
Water plants from the area or from fish tanks
A filter
Now go to where you found them. Find some algae and some mulm in a pool. Scoop that up, put in your tank. That should help kickstart a cycle and also provide food

Feed them frozen bloodworms, brine shrimp, spirulina, dead larvae, etc

I'll take a picture of my crayfish tank, but keep in mind signal crays don't burrow like yours. They do dig tunnels beneath rocks but the key for them is the rock, not the sand
 
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