Toughest fish, pound-for-pound?

[outlaw15w]

Convicts, Midas, Dovii, Black Nasty

 

[MrBlueDream]

Fahaka puffer. Kill absolutely anything in the tank, even tankmates far larger. So aggressive I have read experts even wonder how they can breed. And puffers have crazy bites - stores out there of people losing fingers to them (salt ones) and a YouTube video showing a puffer easily taking bites out of metal can. Plus they have nasty toxins ftw.

I have seen some friendly giant fahaka before. They have individual personality, some can be very friendly with people touching them like a dog.
I have never seen a convict back down from a similar size fish. I think a 2" convict would own any fish it's relative size. A 2 inch aggressive wolf fish, puffer, or snakehead would do nothing to a convict.

 

[hart24601]

I have seen some friendly giant fahaka before. They have individual personality, some can be very friendly with people touching them like a dog.
I have never seen a convict back down from a similar size fish. I think a 2" convict would own any fish it's relative size. A 2 inch aggressive wolf fish, puffer, or snakehead would do nothing to a convict.

Yes, puffers have quite variable personalities, but a mean Nile can kill fish many many times their size quickly! That coupled with the general aggressiveness is why they are still my top vote. Lots of stories on this site alone of a fakaha just destroying fish much larger and some heavily armored ones like large plecos.