Thanks Donya, and @tom, thats the ONLY pictures I've been able to find of them apart from mine... MAybe now I know what it is, I can find more!
Removing it is gunna be tricky, this is the first time I've seen it since I first realised it was there a few months ago.. Ive been looking for it everytime I've got up to do a night feed with the baby!! SO FAR, it's not touched anything, but I will certainly be keeping a turkey baster right next to the tank from now on!