Whats the most "Monster" Nano fish?

[Samt123]

Hey Guys,

Quicks question, what would you guys consider as the smallest, most aggressive, "monster" type fish I can have in a 20G? Looking for something that doesn't get big but also is more aggressive than most other fish. Of course, I can see some answers quickly being a beta or a ram but are there any other cooler more niche alternatives?

 

[deeda]

20G high or long? Rectangular tank?

 

[Deadeye]

Just a few off the top of my head:

Dwarf puffer - smallest puffer species but as mean as a fahaka
Figure 8 puffer - brackish but much larger than dps (though much less aggressive
Clawed frog - Not a fish but fit “monster” better than most animals
Exodon tetra - the mini piranha
Convict - like the dwarf puffer, small but nasty
Jewel cichlid - basically africa’s convict in terms of aggression
Crayfish - Fun to watch and a cool predator/scavenger

In saltwater you could get a fu Manchu lionfish, it may need an upgrade when it gets bigger though
Also saltwater but mantis shrimp, aka a living xenomorph

 

[ichthyogeek]

Depends on where you are and what's legal. Dwarf snakeheads would be the most "monstrous" fish IMO, but they're not legal in the USA.

 

[FLA]

Dwarf pike cichlids are the first thing that comes to mind.
Amazon leaf fish if you want to watch something swallow other fish, but not necessarily agressive.
Brichardi
Shell dwellers definitely fight for their space
Pike livebearer

 

[Gunfleet]

school of pea puffers would fit the bill.
Dwarf Green Pike (compressiceps) are little jerks, but would not do well as the only fish in the tank.
,
are you looking for something that eats other fish or something that's super territorial?

 

[DRUKENMUNKY]

Modestus puffer aka the avocado puffer get my vote

 

[altums85]

Gobies and lots of them are colorful

 

[Rass]

Lots of other options if you were to go saltwater. For freshwater though maybe a scarlet badis, single rainbow cichlid, or nanolutea. You get some personality and color with those, but I've heard badis can be shy. Honestly though, I'd do shellies. Any African shell dweller of your choice really. Multis sound like they do the best when colony breeding, and a 20 long would give them more floor space.

 

[fishhead0103666]

Exodon tetra - the mini piranha
Convict - like the dwarf puffer, small but nasty

Amazon leaf fish if you want to watch something

I wouldn’t do any of the three listed above because of size for the convict and leaf fish and the need for a good size school for the exodons in addition to their size.