It looks like an insect. Perhaps it’s a dragonfly nymph. Still, ontogeny recapitulates phylogeny—see what happens when it finishes insect-adolescence.

It looks like a silverfish to me. These are common household pests along the lines of an ant or cockroach. I don’t think they usually live inside of fish tanks, but I believe they do prefer moist areas.

Silverfish are usually pretty small, I thought. It does look similar, though. How big is this creature?

It is strange because I have not had any bugs in my apartment. I also live by the sea so not too many flying pests around. It is also cold where I live. I do have a bouquet of flowers near the fish tank, maybe it was something that came in on those?

I know the question is probably pretty comical – but its not something I expect to see crawl by when having my lunch!

Maybe it is time to get some fish in there to eat whatever this visitor is. It is almost the same length as the minnow in there so I doubt he is going to do much good.

As for the length, maybe close to half an inch? It has disappeared into the gravel so I can’t measure it now. The photo makes it look slightly larger than it really was, although it was not ‘tiny’.

It’s some sort of insect, and has probably been gestating in your plants. My first thought was dragonfly nymph, also, but I think they usually require flowing water (i.e. stream beds).

Where did you get the plants? It looks like some sort of nymph or other insect.

Okay, this was going to drive me nuts. I actually studied freshwater aquatic insects in Limnology… never, ever thought I’d use the information, so I stuffed it deep down in my brain.

But… success!

I’m pretty sure that’s a damselfly larvae. (scroll down)

@MissAnthrope Hit it. . ..Here’s another picture and website with damselflies.

“Their presence is an indication of a healthy pond environment with good water quality.”

I guess I should be ‘happy’. (lol).
At least it doesn’t seem like anything to worry about. I wonder how THAT got in there in the first place to lay its eggs. The top is pretty much sealed when shut. It is a mystery.

Anyhow, I am happy to hear it isn’t some weird disease carrying mutant. I got the plants ranging from 1 year to 6 months ago, some from Ebay and some from the aquatic store. However, the most logical origination for this little insect is probably from the bouquet of tulips next to the tank. It all makes more sense now. Thanks for the help!

Yup, that’s a damselfly nymph all right:-) I know a large dragonfly nymph can eat a small fish, but if your fish is bigger than the nymph, there shouldn’t be a problem… I wonder what the little guy is eating??

So what happens as it grows? I mean…. it is going to have a hard time getting out of the tank if it gets large. Maybe it will just expire on its own. Should I try to fish it out and get rid of it? (It isn’t going to be easy to find in there) How large is this thing actually going to get?

Oh, Shit! Darwin was right!

@MissAnthrope great ID