The great crayfish experiment

It would appear that one of the black neons has disappeared in the night. I must assume he's been taken, but there nothing left of him at all... not really a big surprise, seeing as he ate his own molting a few weeks ago...
 
They eat every bit of 'em. You might find the odd chunck of flesh when you vacuum, but other than that it will be a mystery! :)

Your cray wasn't playing dead, it was searching for oxygen. Crayfish need very well oxygenated tanks. The agitation from the filter output won't be enough. Do you have airstones or a bubble wand? They will lay on their sides in order to absorb more oxygen into their gills.

Even if the betta isn't eaten, don't be surprised if his tail is damaged. So saying, my crays pretty much leave my fish alone for the most part. I have lost a white cloud or two, however.
 
Originally posted by Traci
Your cray wasn't playing dead, it was searching for oxygen. Crayfish need very well oxygenated tanks. The agitation from the filter output won't be enough. Do you have airstones or a bubble wand? They will lay on their sides in order to absorb more oxygen into their gills.

Huh... it was the only time I've ever seen him do that... he's actually extremely active, even when the lights are on. No bubble wand, but it's an aquaclear 150 on a 10g, it aerates quite a bit.
 
Maybe the additional bioload from the new tankmates caused a decrease in the amount of oxygen he's used to. My o. immunis is the only one that has ever done that to me, and I have her in a vivaquarium, with plenty of pull out spots. So theoretically, she should have PLENTY of oxygen.

As long as he got the oxygen he needed at the time he needed it, it all worked out okay! It is a little scary seeing them lying motionless though. Right now I have about 100 of the buggers. My two p. alleni mated successfully, so along with the 3 adults in their tanks, I know have a breeder tank FULL of baby blues.
 
I have the most docile crayfish ever. Hes a 5.5inch blue and shares a ten gallon with a keyhole cichlid (growing out, currently 1.5in) a shoal of ottos and a shoal of white clouds. He hasnt killed one in the year i've had him. However, on two occasions I have seen a white cloud die and get stuck to the intake, so i just left them there and sure enough there was no sign the next day.

Its actually a pretty good community, i feed the crayfish shrimp pellets as a sort of staple, and the ottos clean the smaller bits off the back and spines of the crayfish. There are many occasions where I will turn on the light in the early morning, or go flashlighting in the middle of the night and find the keyhole, or a few ottos, or even a white cloud "sleeping" in the crayfish's pot/cave WITH the crayfish. But still no deaths.

From what i gather though this is pretty rare behavior.

ryan
 
i've had a crayfish for about a year. i used to keep him in a tank with a school of zebras and one particularly aggressive male blue gourami. the gourami learned quickly to stay far far away from the crayfish, and lived in that setup for six months without problems. the zebras, on the other hand, got picked off one by one, and i finally gave up on that experiment after their school dropped from a dozen to four over a couple months. now, i just keep bitey the crayfish with feeder guppies, which, oddly enough, he doesn't seem to eat at all. it's kind of mystifying, really.
 
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