one fish dead, and it was a female to boot

i fed my discus before i went out for lunch today twice(frozen beef heart earlier and then brine shrimp just before i left), when i returned home from lunch and hour and a half later one of my discus was dead. she showed no signs of stress and had a very healthy appetite, she ate a bit of beefheart this morning and a bit of brine shrimp with all the rest of my fish. nitrates are at zero, and i change 5 gallons of water a day in a 55 gal. so i figured i might as well disect the fish to see if there were any visible worms inside her intestines. it was quite hard to tell because of the amount of bloodworms in her stomach but i wasnt very sure if all of them were bloodworms. i am aware though that most of the bad worms that id be looking for would probably be almost to small to see. i did see however a few in there that were very transperant with a black dot on one end. anyway if anyone could have me with any ideas that would be great. my only idea is maybe she got startled a bit somehow and hit something. i would this stress related if she wasnt so active and if her color was different but she showed no signs of any of this. and i was really hoping to get a female in this group and i am now hoping she was not the only one.

It's such a shame when an otherwise healthy fish suddenly dies.

From those photos, your fish appears quite normal and healthy. If she had worms I would expect to see the intestine a pale pink colour, not the healthy bright red colour in the photos.

The fact that the stomach was full of food is also a sign of a healthy discus.

The only explanation I can offer, is that fish sometimes do suffer from heart attacks. There's no way to tell, and I'm certainly not a vet, so this is just my opinion.

Whatever the cause of death, it was certainly beyond your control.

Hopefully you'll have other females in your group.

since that fish has died a lot of the other fish in my tank have become a lot more jumpy, and are not eating as much. and my other snakeskin is showing the most change in appearance and mood. we'll have to see how it goes i guess

I think a 50% water change is in order, and add a small amount of salt, like 1 heap teaspoon per 10 gallons or 40 litres. That may help to settle them down.

The salt of course, is cooking salt, or rock salt, not table salt which has filler in it to make it flow more freely. :P