As I mentioned in my other post, one of my two new fish was chasing around by my old one. So I had to move the old fish in a 10g tank. Now the chasing issue reoccur among the two new fish. I guess one of them is a female? Since they are all lionheads, so I won't be able to tell the gender by looking at the gill plate. I'm not sure how to tell the gender by looking at the fins...?

My questions are how long this mating chase would last (days, weeks or months)? All the fish are less than 5" long, I dont know their age either. Would a bigger tank help in this issue? I have a 30g laying around and would like to put all 3 of them in it.

I think a larger tank will help the fish from hurting themselves a little bit more than a smaller space but the chasing will probably continue the same. Female fish can get quite exhausted and pushed easily into ornaments etc if you have them so watch out for that.

If you look at the bottom pectorals and see a line of vertical symmetrical white spots on the first fin spine there it usually indicates male.
You can also look at the fishes exit place and see if its an "in" shape" or convex and more "outy" (=female).

Breeding behavior can last a long time, with intervals. Months. It seems to be related to temperature. Rain and storms, spring pressure systems and so on affect the fish.

Is there anything I can do for the female? I mean preventing her being exhausted from the chase? Just put her in a tank by herself?


Any other advices? Thanks

In agroup of fish - if there is one female, the males may both chase. If there are two females and one male, both a female and male may chase. They seem to like to get into the activity. Sometimes, even in a tank of all males, the males will pick one other fish to chase - even though it is male - and worry it nigh unto death from chasing in mistaken breeding behavior.

Trinket is right. The behavior may go on for quite some time. OR it may stop and start and such for a while. Or it may end soon. It really is hard to predict. Having more room is definately a good thing to try. If you wish, in the interim, I have had a lot of luck in using a floating plastic basket or colonder. If you use plastic - one that has plenty of slits in it so that the water flows freely through it, the fish can have all the benefits of the tank of water she is in, but be protected from the rambunctious males. Feed her in there and everything. She will be fine for a week or so like that if you wish. You can try releasing her back into the tank and see what the reaction is.

Having her in the same water may also have another effect I have noticed in some males (usually older ones, though) - they get used to her or tired of her or whatever. They cease to chase even when she is dumping eggs!

It is worth a try - and is a good "instant" protection force field for her.