Strange creature question

[Ste_J]

Now this may seem like a strange question to ask and hopefully somebody will be able to come up with an answer because I am really confused.
I have a 15L "desk top" tank next to my pc which I started to plant but have recently decided to start again with. The only living thing other than the plants that I introduced were some Caridina japonica (which died)and a few snails have found their way in there (wish they would die)
So i'm sat here the other night and i notice what at first i thought was a dead fly yet upon closer inspection it actually looks more like a spider! the "thing" is black with 4 legs head and body.
Since spotting the first i have found a couple of others although they seem to prefer being attached to the plants rather than swiming.

Any ideas because these things look very strange

 

[digital_run]

if it's got 4 legs than its not a spider.. about all i can help you there.

 

[shadow]

It could have been something that was attached to the plants when you got them. Was there anything in the tank except plants when you bought them?

 

[Ste_J]

It could have been something that was attached to the plants when you got them. Was there anything in the tank except plants when you bought them?

Nothing was in the tank prior to the plants going in and these "THINGS" have only appeared in the last few days! I think i'll grow t em and see what they turn into

 

[Ste_J]

Worked it out!

The things in my tank are actually Dragonfly nymph but i don't know how they got in there.
Tank is being emptied this weekend and a good cleaning is lined up, now hopefully i wouldn't have transferred any eggs over to my 66l when i swapped some plants but if i have do you think that a couple of clowns would get rid of any baby nasties that may be around?

Thing

 

[-cAtFiSh-]

mad! you could raise them and breed them and sell them lol

 

[Ste_J]

I could but i'm not gonna

The tank is going to be emptied out and a fresh start made! bloody ugly things anyway and they eat each other!!!!