Posted by mary on April 26, 2005

Q: My son recently brought a crayfish home from school after studying them in 4th grade. We bought 2 more from a pet store and today, a week later, we found 2 of them had died. We bought them fresh elodea but had not given them any protein. We bought cat food today to feed them, but too late.

Should we try to keep crayfish in a tank? What did we do wrong?

Thanks for your consideration in answering our questions.

MK, Harry and Jack

A: I think it's a great idea to have crayfish in an aquarium - they're interesting animals that we rarely get to observe closely. There are all kinds of possibilities as to why two of your crayfish died. You didn't say if the two that died were the two new ones or not. I could easily believe that the crayfish you bought in the store were not the same as the one your son had in school.

Crayfish vary with their needs as there are many different kinds of crayfish. So it is important that you know what kind you have and what its basic needs are. Usually the crayfish in pet stores come from exotic places so you'll need to find out where they normally live and then use that to figure out what conditions are best for them. Some will need cooler conditions than others and most, if not all, will need lots of oxygen in their water. If your aquarium was smallish and you added two more animals to the tank, maybe the oxygen level was simply too low. OR, some crayfish are much more aggressive than others and maybe your resident crayfish actually injured your others - I really can't say.

I wouldn't feed catfood to your crayfish as I envision it dissolving in the water and causing all kinds of a mess. Ask your pet store what they recommend. I like the Elodea (crayfish eat lots of plants) and I have also fed my crayfish goldfish pellets as these sink and have a nice mix of plant and animal products. Good luck to you and I hope you can continue to enjoy your crayfish.

John Wiessinger ( April 27, 2005)