Jordanella Floridae (American-Flag Fish) males fight?!

[ceratophyllum]

I bought 2 of these fish at my lfs. At the store, they seemed very peaceful. There are in very good condition and the biggest Flag fish(2") I've ever seen. I put them in a 20-gallon tank with lots of plants and a female betta. On the first day, they were terrified of the tiny female betta. By day two, they began to ignore the betta and started eating algae like mad. They also started paying attention to each other: chasing one another around. Now it's day 3 and they fight and display a lot . But they do it sort of half-heartedly--sometimes the bigger one is the aggressor and sometimes the smaller. Sometimes they quit fighting for an hour or two. Sometimes try to nip one another every few minutes. At night they are inactive. They continue to completely ignore the betta. The slighly larger male has nipped one scale from the other, but other than that, nothing serious has happened. Both eat all the time (algae, anacharis) and they go crazy eating flakes.

Could someone with some experience keeping these fish tell me:

Should I get more to help set up a pecking order?

Will the probably settle down if left together?

Or is it better to just separate the two I have?

 

[lmw80]

flagfish are normally only agressive towards each other, and usually males are the aggressive ones. If you have the space, I would put a couple of females in there.

 

[ceratophyllum]

But won't mixing males and females just lead to mating-related aggression later on?

According to "The American-Flag Fish" by Wright Huntley,

The only time the Jordanella floridae shows belligerence,
above that of a molly, is during courtship and when guarding eggs. At that time, the female, or any territorial invader, is at real risk from an irate male, who can do serious damage.

 

[lmw80]

yes, but if you do not want to separate them, then I do suggest two females.

 

[Fluff]

I just noticed that my male flag fish is tearing up my angelfish. He has a female so it may be a territorial thing. Looks like they will need to be moved.

 

[Lepomis]

I have three females along with my male. No aggression problems so far. He is always displaying and looking for a receptive female. After they spawn he does get territorial and chases most fish from the selected spawning site. If I remove the eggs all gets back to normal in about an hour or so. I also found that if I disturb the eggs he will eat them up rather hastily. Have not observed any damage to any of my fish yet. Overall I have found them to be a very nice addition to a community tank.

 

[ceratophyllum]

Well, I decided to separate the Flag fish. Now my 20 gal has only a female betta and a male Flag fish. Unfortunately, the Flag Fish has started attacking the betta. He's done some damage to the betta's tail. I think long-finned, slow moving fish are just too tempting for Flag Fish to attack. I guess I will put the Flag Fish back together and take out the betta! I am very reluctant to get more Flag fish as I think they are just flakey fish--sometimes timid, sometimes belligerent.