Aggressiveness

[Benauld]

Pretty much what the title says. Which is the most aggressive species you know of/have ever owned. And how aggressive do you think they are on a scale of 1-10? (1 = lowest, 10 = highest). Whether vented against its own species or others, or simply territoriality, it doesn't matter. I've not seen one around, but think it would be useful to have some sort of species list ranked by aggression. I mean to somebody getting into the hobby, and maybe hasn't done all the research they can, or should, which are the ones to avoid due to poor temperament?

Are bettas bad-ass? Or, are they mere kittens next to african cichlids? Do gouramis pack a punch, or are they lightweights next to the RTBS?

Start calling 'em!

 

[MermaidMel]

I had a mean ruby shark once, had to give her a tank of her own, she terrorised her tank mates, jumped out the tank - all sorts. Nightmare, but beautiful and such a face on her. I want another someday when I have room for a little tank again. She was a good 7/10.

And a lot of barbs are hectic too, tigers especially. Terrible fin nippers.

 

[jayjay]

Parachromis dovii or if we are doing this respective to size maybe, Neetroplus nematopus when breeding.

 

[The-Wolf]

Distichodus lusosso & Morulius chrysophekadion are the two meanest fish out there.
they will kill simply because they can.

 

[finchfarm]

Don't know if I'd say it was the meanest, but our old Pacu killed every fish we had in our tank with the exception of a Bala Shark and an old Pleco we had.

 

[Straydum]

snakeheads. especially when they are with a spawn. 9/10

 

[CFC]

Any of the Hemibagrus species are pretty nasty fish but Hemibagrus wykkii and Hemibagrus Wykkioides are both contenders for the most aggressive freshwater fish in the world, these will even bite heaters in half if you put them in the tank and anything living will be dismantled the minute the lights go out.

 

[GuppyDude]

Female masquito fish, while pregnant. Not a whole lot of size to them, but man can they shred up a tank of guppies.

 

[-germ-]

I'd second The-Wolfs opinion on Morulius chrysophekadion being a shockingly aggressive fish.
Also while possibly not quite what the OP intended;
Hillstream loaches, while practically incapable of doing any real damage are tenacious, territorial and will put every effort into their battles. Literally chasing their opponent round the aquarium until he/she finds a safe hiding spot or they can engage in a true 'sumo' battle, often losing their colour as they battle which is assumed to be as a result of the energy spent in pushing their opponent. Stunning to watch.

 

[nmcturner]

I've never had any cichlids other than angels so I can't speak for them, but Green Spotted Puffers are the most aggressive that I have ever had. Usually minutes after introducing a new fish it was torn to shreds. That is why I had to get rid of them.

-Nick

 

[Aphotic Phoenix]

Aren't Hydrocyon vittatus (Tiger Fish) rather nasty?

 

[nukeonekitty]

Melanochromis chipokae. Hands down.