Question about my female swordtail?
I've got two lyretailed swordtails in my 55g, a male and female. The male is fine, as are all the other fish, but the female is acting strangely. She's still eating and active, but about every 30 seconds she does a sudden, spasmodic "dart". I noticed she has a slightly strange-looking patch of scales on her side--it looks like there's a small bump covered by a clear membrane, with something white underneath it near the top. I tried getting pictures, but it's hard to see:
http://img.photobucket.com/albums/v38/Runan/sword001.jpg
http://img.photobucket.com/albums/v38/Runan/sword002.jpg
http://img.photobucket.com/albums/v38/Runan/sword003.jpg
http://img.photobucket.com/albums/v38/Runan/sword005.jpg
I'm thinking it's a parasite of some sort, but I'm not sure. Any ideas?
Unfortunately, she was the only female in the tank when I got her and the male. However, she's actually the more aggressive of the two, and he rarely bothers her any more.
There's still something not right about her, and the "darting" worries me.