What is this?

[Armando_Villasenor]

Does anyone know what these little lines are? They look like dashes and I’ve noticed them multiplying. Not sure if they are a form of algae.
Thanks

 

[apt220]

Some type of flatworm?

 

[Reefnewb]

Flatworm for sure

 

[apt220]

A wrasse would probably go to town on those

 

[reef lover]

No wrasse? Then siphon out as many as u can.