To most people who don't teach science classes, it's a bug.
Yes, I would remove it from the tank. It probably came in with your plants.
While I get that, correcting the improper use for me is the same impulse that you would have if some one referred to a convict cichlid as an African. Please understand, not trying to be rude or mean.
Ok... I get knowing the fish lexicon... But bug latin? Thats it, i'm going to the library! Heh
Sorry, he he, but it happens to be one of those things I cover extensively in my aquatic class, and I'm in the habit of gently correcting any misusage that occurs when referring to the critters in the bog, so its kind of second nature (is misusage a word or did I just make that up ~ oh well, grammer nor spelling never was my strength, guess thats why I teach science LOL). Why bother going to the library, just ask and I can probably help you out with at least the order name of anything thats aquatic in nature - lots of useless info rattling around in this old brain. With the bog tank, use of the order names pretty much becomes second nature in my classroom.
Ok I will do that next time I find it, I wonder how long it has lived in my tank and what it has lived on!? I shudder to think it could have been preying on my fry!
And yeh, I knew the technical term wouldn't be bug or creature, just had to grab attention somehow! Do you think it will be a one off, and with it not being developed it couldn't have spawned, etc.
Last one for anyone interested I zoomed the pic in
Its obvious from that last zoom in that it is definitely a damselfly, and I would remove it (of course, I'd put it in its own tank, but that is just me and I'm a little eccentric as you can no doubt tell by my tank). I doubt that its been eating your fry, unless it is quite large; there general food source is microorganisms (like daphnia and copepods) or other small invertes. I have two that are at least 1 1/2" in my bog tank, and they've never bothered any of the fish yet.
As for it having spawned, impossible as they only reproduce as adults, and what you have is the nymph stage. It is possible however that you may have gotten more than one with your plants, so keep a sharp eye out.
Hope that is helpful, and again to everyone, please understand I wasn't trying to be rude towards anyone.