I was just looking at my tank and noticed these things. After a quick search, I think I may have flatworms. What have you guys done to rid your tanks of these guys, if they are indeed flatworms?
Melanarus wrasse did the trick for me years ago.
Not to hijack the thread, but will a Melanarus wrasse work with a yellow head jaw fish. This wrasse is a beauty...
Melanarus can get pretty big. I had one in my tank for several years but lost him about 2 months ago. Best wrasse Iv had.
+1 a must have just a great fish you can see him searching all day