Can anyone help me?

[b3noodles]

Hi all I am new to this so please bear with me. We have just noticed these little white things on the glass of the tank. I have seen a couple of pics that look close to what these are but I am not sure. They are pencil tip size seem to be almost transparent with a larger spot in the middle of them. They have forked fin? They move around and head down to the bottom when we turn the light on. We noticed then after we fed frozen brine shrimp- any relation? Everything else seems to be fine in fact we have a starfish that we didnt buy!(although he seems a bit deformed) LOL Any suggestions?

 

[Anemoneman]

The forked fin makes it sound like a flat worm or planaria. Could just be copepods. Hard to say w/o a pic.

 

[something_fishy]

are they hard and stuck to the glass, or are they flat and brownish and look like fish flakes, if they look like flakes, then they are flatworms, a bad thing. If they are white and small hard dots, they are copepods, a good thing.