Odd female sword behavior

[ronin]

I have a group of 3 male and 4 female swords and there's one particular female sword who for some reason keeps getting picked on on the head by the dominant male in the group. He keeps coming over and biting her on the head in the area between the eyes. Nowhere else. And instead of just trying to run away like normal, she just keeps lowering her head and backing down with the male in pursuit until she either hits bottom or gets into some plant cover. And it's only the dominant male that does this. However, when I had this male segregated before, I noticed one of my junvenile guppies doing the same thing to the same female sword. And the guppy was like a quarter of her size! I was thinking maybe she had an open wound on her head now or something (can't really tell) so currently have her separated in a big floating breeder cage and am dosing the tank with a little Pimafix and Melafix. Anyway, has anyone ever seen this sort of behavior before?

 

[Tempestuousfury]

No. Just a bit of chasing and the like.

Options are to either quarantine the bullying male or to gte more females in an attempt to get the male to back off.

I don't know why the male would attack the female, other than if she were not willing to breed with him, though it seems that she is submissive and would have relented to his advances. If it doesn't seem to happen with the other fish, then maybe the male feels that the female is weak and deserves to me weeded out.

 

[Polardbear]

Are you certain she's a "she"? Some swordtails develop into males later than others. I have a black swordtail that I've had for 3 months that I would have sworn was a female until a coupl of weeks ago. He's easily as big as any of the females that I bought at the same time and just started growing a tail a couple of weeks ago. His gonopodium developed about a month ago (until then it kind of just looked like an anal fin with a bit of an extension) and his sword started a couple weeks later. I really wasn't sure about him until a week ago. Throughout the 3 months I've had him the other males left him alone for the most part but he was always very submissive to the other males. Maybe your girl is really a juvenile male and the dominate male is making sure he knows who the boss is.

Also, what size tank are they in? Does the picked on one have room to get away and places to hide?

 

[ronin]

Are you certain she's a "she"? Some swordtails develop into males later than others. I have a black swordtail that I've had for 3 months that I would have sworn was a female until a coupl of weeks ago. He's easily as big as any of the females that I bought at the same time and just started growing a tail a couple of weeks ago. His gonopodium developed about a month ago (until then it kind of just looked like an anal fin with a bit of an extension) and his sword started a couple weeks later. I really wasn't sure about him until a week ago. Throughout the 3 months I've had him the other males left him alone for the most part but he was always very submissive to the other males. Maybe your girl is really a juvenile male and the dominate male is making sure he knows who the boss is.

Also, what size tank are they in? Does the picked on one have room to get away and places to hide?

I'm pretty sure it's a she as the anal fin is rather large and fan-like with no gonopodium-looking extension at all. What made me thought that it would be an open wound causing the problem is that at my LFS I saw a tiny little juvenile platy terrorizing a brushnose pleco that had a noticeable sore on its head. She would just keep following the pleco around and bite at the sore. Pretty much the same thing here cause the male (and that one juvenile guppy) would just bite at her head, nothing else. If it was a simple matter of showing who's boss, the male would usually go after any part, not just the head.

They're in a twelve-gallon tank with lots of swords, Java ferns, and moss so there are places for her to hide. It's just that whenever she ventures back out, she gets driven back in all over again. So there seems to be two issues here really:

1. Why do they just pick at her head? And...
2. Why doesn't she just swim away like a normal fish instead of acting really submissive? None of the other female swords act like this.

Anyway, I was thinking of keeping her segregated for a week or two to see if the wound (if there is one) heals and then see what happens when I let her out.