Mean Mono

[Sara0229]

I did a lot of research on Mono Argentenus, or so I thought, before I bought them. I had to have them shipped and unfortunately only three of them survived the trip (shippers fault!) Anyway, I was expecting a schooling fish that may eat smaller fish BUT I now have one fish who is a terror! He chases the other two around and is now becomming larger than them, the other two were smaller to begin with but they don't seem to be growing as fast. They are also fin nipped. I'm not sure what my best move would be, seperation until they are the same size, more plants??? They are in a 55gallon with 2 bumblebee gobies, 3 small gupppies, and a molly (about 2inches- he was a lone adoptee). Thoughts?

 

[jonny5]

well first off it should be clear that they will need a minimum of 100gallons when they are older, preferably 150g+
But i had the same issues, i have 3 monos and as they were growing one was larger and picking on the others. However, i had an orage chromide which chased all of them around and kinda made the aggresive mono go defensive.

In the end it all worked out and all 3 of them are 2 years old now and the smaller ones grew up (although slower) and there is still the occassional fights betweent them but not too bad.

If your mono is very aggressive then he might kill the other two, a larger tank would solve the problem imo.

 

[nmonks]

As jonny5 suggests, and as you'll see reported by some other Mono-keepers, Monos can be aggressive. It's really much like you see with Tiger Barbs or Angelfish -- however much they're social in the wild, in small numbers in small tanks, they often become aggressive. One solution is to add more of them, preferably an odd number altogether, i.e., 5, 7, and so on. Another option is to add something that disrupts their social interactions; in other words, a bigger, more boisterous fish. Green Chromides can work well, but the ideal are probably Scats, which are smart, greedy, and well able to look after themselves.

An appropriate amount of space is important, but your 55-gallon tank should be okay for a few months if these are still small specimens. But as you've learned already, they don't "move" well, so it's best to get Monos settled into their final aquarium as soon as you can. Adults are especially sensitive to being moved, and while they normally recover okay (moved them many times myself) they turn black and it can look very alarming!

Do note than Monos are predatory, and small fish like Bumblebees and Guppies will likely end up being eaten. Mollies, on the other hand, can work rather well.

Cheers, Neale