Posted by Erin Coyle on October 14, 2005

Q: We have a "pregnant" crawfish in our tank at school. She has been carrying the eggs (which are pinkish to dark red in color) for at least 6 weeks. They now look like they are covered with tiny white filaments, like hair. The ones at the back are really thick. I also noticed that she had two white hair-like things attached to her head, between her eyes. Any ideas of what they might be? My students are very worried!

A: I'm almost certain that I know what the problem is. Sounds as though your crayfish has a fungus on her eggs. These are not going to hatch - sorry. You didn't mention if there was a male crayfish in the tank so I'm wondering if the eggs simply weren't fertile, therefore can't hatch. Either way however, this does happen in nature and might be a good "lesson" for the kids. It's quite common for tropical fish enthusiasts to have their fish spawn only to watch the eggs develop fungus and die. The best way to avoid a fungus from developing on your crayfish in the future is to keep the water clean - a pump and filter should do much to help here.

>

If I were you, I'd remove the mother crayfish, turn her upside down and carefully remove the eggs (they're glued to her tail). If you don't do this, the fungus may gradually envelope her. If she does have some fungus on her shell, you can also take a clean dry cloth and gently wipe the fungal strands off. Please feel free to write and ask if you have further questions - I'll do my best to help. I know this must upset the children but in nature, life is not a sure thing! My best to you and your crayfish.

John Wiessinger ( October 16, 2005)