Ruby Shark - Deceased!

[Nauplii]

I came home from college today to find that my ruby shark was floating dead in the tank.

I cannot understand this. I fed my tank 2 days ago ( because i wasnt here for 2 days) everything was fine. My mum told me that yesterday he was swimming around fine, and today its dead.

I checked the parameters on my tank: Nitrite: 0, Ammonia: 0.

Theres nothing wrong with the water, and ive doen other tests, oxygen, nitrate, PH, KH & GH, but i cant see why it died?

Anyone got an idea?

 

[Tokis-Phoenix]

How are you other fish holding up in the tank? Any symptoms or odd behavior you can see in them?

 

[Nauplii]

No symptoms, odd behaviour. One of the fish has a stringy white.. poo lol. But that is it.

 

[WILDER]

How old was he.
Sometimes it just one of those things that happen, so sad, but if he was showing no symtoms it hard to say.
R.I.P.
Just noticed you said stringy white poo that can mean a numbers of things.
First what do you feed the fish, as that a sign of constipation sometimes.
Also it can indicate a bacterial infection to internal parasites, check the anus on the fish to make sure its not enlarged or red and inflamed.