Petshrimp.com Discussion Forum

I've started keeping blue O. immunus. I have a friend in upstate NY that breeds bait. He found 5 blues one year out of all the harvests (tens of thousands of crays) and started a pond up with them. He invited me up and I came home with a load of them. The "pond" is now loaded with them.

These are a great addition to the large crayfish hobby. They are very peaceful as crayfish go. They do not actively hunt fish, they get along with each other, and like most crays, they are really fun to watch. They also don't get overly large. Only about 4".

I have 10 in a 40 gallon tank, and I've not seen any real squabbles. They allow one another to actually climb over each other without protest. They are plant eaters, but that is about the only down side I've seen.



Here is a shot of when we caught them:

These are nice looking crays for sure. However, another downside is that they supposedly don't breed in home aquaria as they are cold water crays (as opposed to the blue P. alleni, which come from semi-tropical to tropical Florida). I can't confirm or deny this as I have never kept this species, but maybe you can attempt to breed them (in a "warm water" tank) and see if if you are lucky.

They breed in the spring and fall and do need a cooling period of a few weeks below 55 degrees. I plan to set up an old refrigerator to see if I can get them to breed that way.

I was told that in the fall you just set up an aquarium outside, and then bring them back in once the females berry.

I think the difficultly in breeding will be off-set by their non-aggressive nature. Alleni and Clarkii both kill each other if you try to breed very many, and the babies eat each other like crazy. That is not the case with these guys, so one may well get many more with one berry than you could get from the others. Each female can carry 100+ eggs.

Time will tell.

BTW- they do just fine with Rabbit food, and they like it.

BTW- they do just fine with Rabbit food, and they like it.

Rabbit food as in compressed veggie pellets? I may have to try those out on the shrimp and dwarf crays as well. My wife has a pet dwarf rabbit, so there's plenty of pellets handy...

What kind of substrate will you be using? Do you think they will need something like clay or soil to burrow or do you think gravel would work?

Keep us updated, this is interisting.

Paul L

At first I was worried because copper sulphate is listed on the list, but way down. After feeding for a month+ all seems well. It is only 12% protein, so I do add a little extra high protein food, but this has all but eliminated my food costs.

LOL, We raised rabbits when I was a kid (flemish giants). I would have never thought of feed ing rabbit food to crayfish!

Badflash, are those tadpoles in the net with the crayfish? If so, those are HUGE! We used to feed tadpoles to the crayfish we caught as children, but those would be enough to feed one for a week, particularly with how messy they were at eating.

michiganmale248 wrote:What kind of substrate will you be using? Do you think they will need something like clay or soil to burrow or do you think gravel would work?
Paul L

These are not diggers. In the "Pond" it is prrtty much bare bottom, with loads of clay pot hides. In my 40 gallon breeder ther is pea gravel, clay pots, texas holey rock, etc. They mostly hang out & don't hide except when they molt, or when the females have eggs. I saw this with 2 of the females I got that were berried. Once the eggs hatched, ot they came.

They do enjoy the plants I give them and seem to eat just about any plant they get.

pixl8r wrote:LOL, We raised rabbits when I was a kid (flemish giants). I would have never thought of feeding rabbit food to crayfish!

Badflash, are those tadpoles in the net with the crayfish? If so, those are HUGE! We used to feed tadpoles to the crayfish we caught as children, but those would be enough to feed one for a week, particularly with how messy they were at eating.

I got a book on raising crays for bait and rabbit food is what this guy used. The tadpoles are bullfrog tadpoles. We caught a lot more tadpoles than crays. The tads were bigger than most of the crays too.

I'm wondering if they couldn't be dried and ground up for cray food.

Hello,

I don't know what the price range is in your part of the country, but the first cray farm I worked with advised that commercial catfish feed was perfectly balanced for crayfish. I personally don't know how it works for them, but it's approximately 20% protein and highly plant based. I've used it for fish and snails in the past with slightly better than decent results. This seemed like a suitable suggestion here. Drawback is that it's normally sold in 50 lb bags, but usually only $20ish.

Another note that seems applicable to this thread since you planned on cooling them to breeding is that a DIY cooler can be made for far less than $100 bucks and a couple hours time. I've used them for raising axolotyl in the lab about 15 years ago with good success.

In essence, you're plumbing hose into a dorm fridge. The small fridges can usually be picked up fairly cheap this time of year because kids leaving school and want something that holds more than a case of beer. If you place shoe box trays on the shelves filled with saltwater, and coil flexible silicone into them, you can maintain constant temp fairly easily. Also, the thermostats are easily adjusted to hold a constant temperature and will not shock the critters with sudden swings. One piece of advice though is to cover the tank bottom and sides with 1 inch styrofoam at least while using the cooler. This cuts down on heat loss and maintains a more steady temperature than without.

Just a couple things that I thought may help

Larry Vires

dude, you sound cooler every time you say something. keep this up and i'll be following you around clapping coconut halves together!

this should work on mad toms too, right? i was going to try the old fashioned way and stick a tank in the garage for the winter, but this sounds better. too bad i just sold my spare fridge!

OK, I'm not suggesting that anyone do anything like I'm going to describe, but I built one of these a few years ago, as a beverage cooler. Until I attached an adjustable thermostat I would freeze drinks with it. Kind of hard to open a bulged can of frozen soda!

If you're familiar with computer mods (yes, I'm letting my Geek show , I guess it comes from being a database programmer), similar results can also be achieved with this convoluted method;

Parts:
a fair sized copper radiator (heat exchanger, more can be used in parallel)
a computer PSU (wired to run while not connected to a motherboard
two peltiers attached with thermol epoxy to ...
a copper cpu cooling unit
2 heatsink/fan combos
thermol epoxy
silicone sealant
An Igloo type cooler
a small water pump
antifreeze
a medium sized drink thermos (coolant reservoir)
pipe insulation that matches the OD of the tubing.
Optional parts,
a computer bay attachment with thermostat and heat sensor(s)

Here's how to build it.
Drill/melt an set of inlet & outlet hole in the Igloo cooler.
Insert a length of tube into each hole.
Epoxy the peltiers to each side of the cpu cooler (it may be difficult to find the right type). make sure that the 'cool side' of the peltiers are attached to the cooler.
Epoxy the heatsink/fans to the 'hot side' of the peltiers.
Attach the tubing on the inside of the Igloo to the copper radiator.
Attach the pump outlet to the intake tube of the cooler.
Drill/melt a hole near the bottom of the thermos and another near the top (but below the water line and threads).
Attach a tube to the thermos at the bottom outlet hole.
Attach the other end to the intake of the pump (you could also insert a flow meter at the junction to monitor the coolant flow rate).
Attach the other tube that was inserted into the Igloo cooler to the top of the thermos.
Use the silicon to seal all attachment points (of the cooler and thermos).

The whole cooling system is now plumbed, except for one of the radiator connections.

Now connect the heatsink fans computer PSU. Plug in and turn on the PSU to test the fans. Next connect the peltiers to the PSU. Again turn on the PSU and make sure that everything works. Shut off the PSU.
Now fill the Igloo with water about 3/4ths full. Fill the thermos until full.
Make sure that the radiator and the disconnected tube stay under water. Now turn on the water pump. Again make sure that the disconnected points are submerged. Check the water level of the thermos; add more water if it drops too much. Once air bubbles stop coming out of the system, turn off the water pump and attach the disconnected points.
Next seal the Igloo and thermos and turn the water pump on. Let it run for a while, check for leaks.
Once all leaks are fixed, attach pipe insulation to the tubes.
Now let it run for a hour and see how cold the water in the igloo gets. If you get too close to freezing say under 10C or 40F add antifreeze to the thermos and the igloo.
The system I built was essentially that. I'd put soda into the igloo to cool it down. To cool an aquarium, just take a water pump and run a line from the aquarium, into the Igloo, loop around the copper radiator, and back to the aquarium.

I imagine that the longer the aquarium line in the igloo is, the more efficient it will be at transferring heat/cold.

Hello,

I don't know if it's the meds I'm on right now, or I'm just not geek enough. OK, now that I think of it, it's probably the meds. Do you have a diagram? I'm wanting to experiment with something similar for a large central system for Corydoras from Argentina and southern Brazil. This sounds a bit more precise than my version and should also be possible to upgrade rather easily to handle the larger volume.

Larry

Sorry, I didn't notice your reply. I'll make a diagram and post it tonight.