Yesterday, I noticed my red mystery snail and black mystery snail on the part that goes into tank to suck water/**** out of the tank and into the filter. The black one was sucked in pretty bad, and when I got him detached, he may have been injured.
The red one came detached on it's own when I lightly tapped the filter. But now today I noticed about 10 little black lines/dots on the red one. I can't see them anywhere else in my tank. (Pic included)
What are they? Are they harmful to the snail (s) and/or fish?
I currently have the black, red, and a blue mystery snail. Plus 8 lemon tetra in the 20 gallon tank.