JardiniBoy;575975; said:I'm still undecided as to whether mine is notopterus notopterus (NN) or papycranus afer (NN). Initially I thought it was NN. I've since then read that PA swims differently from other knives. Instead of swimming backwards and forwards by moving its bottom fin in waves, it moves its whole body from side to side (like an aro or an eel).
I now think it could be PA because it seems to swim more like an aro than my other knives (CK and RCK). It makes quite a big difference because the PA will eventually be twice the size a NN would Im obviously hoping for a PA!
Sorry for hi-jacking your thread Li...
Yeah...I've never seen P. Afer swim around. I usually see them huddled together in a tube
but im sure that is a ck 
