Help!! 1 dead swordtail

[phishphood]

One of my female swordtails had been looking lethargic and unsociable for a couple of days. I have been changing the tank around a bit, so I figured she was just a little upset and a bit stressed out. I put some Liquisil General Tonic (interpet) in the tank, to try and help her out. The day before yesterday, I noticed she had either had her tail nipped at or had drastic fin rot, as 1/3 of the tail had been eaten away overnight, none of her other fins were affected, but they appeared a little clamped. She was still hiding and resting on the gravel. I caught her and put her in the small tank so I could treat her. I left the cories in there to keep her company and cos theres no room in my other tank. I treated the small tank with Anti fin rot and fungus (Interpet). She survived that night and yesterday, but I noticed one of her gills had gone bright red last night. She did not survive the night.
The problem is, yesterday, I noticed the other female swordtail also resting at the bottom, not hiding, but laying on the gravel and not moving. I caught her and put her in the small tank, so I can keep an eye on her more easily and so she wouldn't bee hassled by any of the other fish. She may also possibly be pregnant. She is usually a very skittish fish and impossible to catch, but I caught her really easily yesterday. She doesn't have anything wrong with her fins. The only thing I can see is that she is not her usual self.
Any help would be much appreciated, she's a beatiful fish and I really don't want to lose her.

P.S. Water parameters were all normal when I checked 2 days ago when this all started, and none of the other fish appear to have any problems.

 

[sandyd]

I was wondering how your swordtail is today? Usually right before labor if she is pregnent, they spend alot of time relaxing. Hopefully that is all it is. You said that the other one that you lost, sorry to hear that, was missing pieces of its fins? If it was fin rot, then you need to keep an eye on the other tank mates. You said tank water was fine, but i was wondering if you had recently done a water change or aded any one new to the tank? Also you said that you were changing things around, if you added any new stuff to the tank, did you make sure to wash it properly before putting it in? I am just trying to figure out what happened to the swordtail so that hopefully we can prevent it from happening again.
Sandy

 

[mtdewlover]

What other fishies are in the tank with these guys? I know some swordtails can be awfully sensative. Are they getting enough oxygen in the tank? Are other fishies being mean to these guys?

 

[phishphood]

The other one died last night. She was a beautiful fish, I'm going to miss her.

I was only moving stuff around in the tank, nothing new was added. I only did normal water changes. There is a massive airstone in there with loads of bubbles and the filter produces plenty of surface disturbance anyway. There are guppies, 2 silvertip tetras, a male swordtail and 2 clown loaches in the tank. The clown loaches were added 2 weeks ago. None of the other fish picked on the swordtails, the swords were bigger than them and "ruled the roost". All the other tank mates are fine, it was only the two female swordtails. I've got anti fin-rot stuff in both the tanks now as a precautionary measure.

I have to go away for a couple of days tomorrow, so I hope none of the other fish come down with anything, my sister is looking after them. They all appear fine at the moment though, so I'll keep my fingers crossed. If anyone has any ideas as to what happened to my fish, I'd appreciate your help.