I came home from work today to a terrible surprise. The smaller of my female swordtails was floating dead in "her" plant in the corner of the tank. Two of the fry were nibbling at her; it was ghastly. SIP, Little Sister. You were my favorite. Why do the good die young?
I didn't have the presence of mind to take a picture, but she had a couple bumps on her, as though she'd gotten a knot from running into something. One bump had a spot of white in the middle like a pimple. I noticed a bump on her three days ago while I was doing a water change, but since she was active and eating normally I thought I'd keep an eye on it for a bit. Apparently that was the wrong move.
Does anyone know what this was? She was one of three swordtails in a cycled 20 gallon, sharing with one male and one other female. She'd had a small litter(?) earlier this week. The water is 80 F, and I've yet to test the water since I've just scooped her out and given her a burial at sea, but as of two days ago before I did a partial change it was at 0 ammonia, 0 nitrites and between 5 and 10 ppm nitrates.
Anyone with more experience have any wisdom to offer? I'm terrified of one of the others getting whatever it was she had. Was the water too warm? Was she stressed? Is it a bacteria?