Identification please

[fish fillet]

Could someone please tell me what these are. They appeared in my sump recently and have transparent jelly like bodies with a brownish mass in the centre. I haven't noticed any in the main tank just on the walls of my sump.

Sorry pic is a bit blurry.

Thanks

[mogurnda]

They look like flatworms to me. If you have corals, they can be a real problem, basically smothering the corals. Although I have never tried it, I have heard very good things about Salifert's Flatworm Exit product.

If it's a fish only system, they probably won't cause much trouble.

[fish fillet]

I do have some corals. Will they be a problem if they're only in the sump? Like I said, I haven't seen any in the main tank.

[mogurnda]

They aren't a problem in the sump. However, like cockroaches in the neighbor's apartment, they don't tend to stay in one place. Keep a close eye on the corals.