I've added a couple of new plants to my Red Cherry set up recently and have just seen a little fish swimming about the bottom of the tank. It's only about 6mm long, spotted head and what looks like a pointy tail. The only way possible for it to have got in is either on the leaves of the plants or in the growing media. The plants are Subwassertang and a pot of grasses. It seems to be lurking about in or near the Subwassertang so I think that's the likely culprit. I'm not bothered about it, in fact it's pretty cool. Anyone else had this, or anyone guess at what it could be. Sorry, no chance of a photo, it's too small and quick.