How important are snails?

[asylumdown]

I've never seen them behaving in a predatory manner, just voracious. They never seen to get full, and their little mouth tube can stretch to pretty unbelievable lengths if they're trying to get at something in a hard to reach spot. When I was trying to catch my tang, I kept thinking the fish were eating the food in the trap and I was just missing it, until I realized the snails would climb up on the outside, and stick their mouth bits in through the breathing holes on the trap. I think one of them extended his feeding tube like 3 inches in to the trap to get at the mysis...

I'm going to reduce the number and see if one or two snails still causes me grief