I have 7 cochu's blue tetra in my tank at the moment and boy are they characters!
However, I do have a quick question about their behavior. Of course they are very active and swim all over the mid to upper part of the water column. BUT! I noticed something very strange and kinda fun to watch... As soon as i turn off my lights (and my moon lights come on) every single one of the blue tetra shoots to the waters surface and swims right at the surface of the water. A few of them even seemed to sort of jump out a little bit (I have a hood no worries!). They've been doing this for about 15 minutes so far tonight.. makes me wish I had better night vision!
Is this normal? Its almost like theyre doing some kind of weird tetra dance when the lights go out. Ive never seen any fish do this before.