I've used this before with great success...
Take the shell of one of those clear bic pens, remove the guts, and any endcaps. Jamb the bottom end into some flexible tubing (I forget which diameter I use, but it needs to fit tightly around the pen shell.) Then, use it to do a water change, using the open pen tip as your suction "tool". You can suck the little bastards right up, and if they do pop, you get most of the spores in your bucket.
Emerald crabs also will eat them, but I had one that didn't eat a one, so that doesn't always work.