It's so hard to say, with all of the regional differences.
To be honest, I have never seen or kept bowfin's in person, but have read about their nasty demeanor. I have however seen a 12" snakehead almost instantly inhale a 10" pike. (In which both fish died in the incident..owner was a tard for trying to put them togethor) So thats why I would probably have to lean towards SH.
Also, Bowfins are native to N. America right? I thought we were keeping this discussion in the terms of home aquaria and 'tropical' species. Perhaps I am being ignorant, and species of bowfin do exist in tropical climates. However, if we are taking US Native fish into consideration then we left out a HUGE amount of fish (Many we don't know much about probably).. Then you would have arguments about Tiger Muskies, and Northern Pikes, and who else knows what other crazy cold water creature would be 'Nutzo' in home aquaria?
Since N. American native fish are not kept that often, or observed as often as the 'Popular' predators (Cichlids, Primitives, Puffers, etc), then we really have no way to gauge what fish would be the most aggressive in home aquaria. I am NOT trying to de-rail this thread and bring native fish into the mix, I would prefer to keep it based on fish that are COMMONLY kept by monster fish keepers accross the world.
I was wondering about the marbled sleeper goby today, as well as some of the nastier catfish. However, I try to visualize in my mind what would happen... Say you take 2 fish, drop them in a 90g tank at the same time, and who wins? I would have to put my money on a Channa or a Cichlidae because they would regain their surrounds quicker, and realize they need to establish territory ASAP. Gobies, Puffers, Lungs, Primitive fish would all be in a state of shock, and their first instinct would be to find cover and become 'settled' in their new surrounds..
That is why I visualize a Channa or Cichlid going after one of these less 'territorial' fish, before that fish can get a chance to react. Hence, the Fahaka Puffer getting demolished by a Channa, due to the Puffers natural reaction to change in environment. The puffer (or alot of the other preds mentioned) will not have the mentality to react and become territorial, nor the ability to flare gills and lock jaws in confrontation.
If they both have the ability to become established, and then a divider is removed, it can be a different story. I still feel that the puffer would not instantly attack anything, but rather bite out of curiosity. The channa on the other hand, will be WAITING for the divider to be removed, so it can 'claim' the other half of that tank.
Interesting scenario: 90g tank, divided in half. One side houses the most aggressive Channa Sp, the other side houses a Dovii cichlid. They both weigh the same. You both let them become established for 2-3 days. Divider removed, who wins?
I noticed no one has mentioned Managuense in this either, however after attempting to put a big Jag and a big Oscar togethor, I would not add the Jag to this list. Unfortunetly this Oscar has a serious attitude problem, and actually went mouth-to-mouth with the Jag and won. I was extremely saddened, especially since this Jag was the most aggressive one I have ever seen. (Would jump a foot out of the water to bite you.). Later on that same Oscar got his fins shredded over night by a Red Devil of similiar size. Each case was an isolated scenario though, in which other fish may have played a roll, or perhaps the order in which they were introduced. Remember though, Jaguar cichlids are not incredebily thick or broad bodied, so if it were to attempt to fight an Oscar or Red Devil of the same Weight, it would own it, IMO. Jags sure are nasty for there 'medium' size, IMO.. and Convicts are nuts for their 'small' size also..
So who would win between Dovii and Red Devil? What other crazy large cichlid am I forgetting?
Also, I have not had alot of experience with Wolf Fish.. Will they flare gills and fight with a channa? I know their teeth have the ability to puncture, which could disable a channa quite fast. However, would the Wolf Fish just sit their and wait for the Channa to make his move? In that time the Channa could possible disable (or stun) the Wolf Fish long enough to finish
him off.. Tough Call.
Remember, try to visualize what would actually happen between the 2 fish. Some fish have a natural instinct, that other 'Predators' don't. Usually the fish with the insinct to claim as much territory as fast as they can, will have the upper hand. Regardless of how powerful or fast the other fish is, if it's not ready to throw down immediately, it's going to get stunned, disabled, and killed pretty fast.
Damn, this is like UFC for fish.
Too bad we can't cheat, or I would go with an Electric Eel
