Please help. Healthy orander suddenly died

[LeanneEllis]

My orander was over 10 inches long. I’ve had him since he was 1.5cm long. He had a fungus when I first got him, treated and recovered but left with a scar on his side just behind a gill. He’s in a 240 litre tank with a black Moore and 2 dojo loaches. He grew up with these other fish so nothing new as they all played well together. He’s been in this tank for 2 years. Nitrates/nitrites and ammonia all at zero and pH between 7.4 and 7.8. I use mineralised RO water as the tap water in my area is filthier than my tank. Fed as usual this morning and when I got home from work he had died with no marks on him, beautiful long tail in perfect condition and brightly coloured fish. No parasites or fungus in the tank and water crystal clear and normal cool temperature as it has been the last 2 years. I have no idea what could have caused his death as the other fish are perfectly healthy and there are no marks on him. Does anyone have any ideas? I just need to make sure my other fish are safe. My water puppy (orander) was the life and soul of my tank. He would spit substrate at the wall (or a snail) to get my attention and if that didn’t work he would splash me. He was my water puppy and I’m absolutely devastated. If anyone has any ideas I would be most grateful. The last picture in these is when they all settled down together to watch tv. My water puppy was addicted to the tv ?

 

[WildFish99]

What is the scientific name of the fish? That is so sad! Its really hard when a fish friend passes, it could have been something internal, a lingering issue from before you got the fish (especially considering it had fungus before you even had it), or old age. I am unsure how long this type of fish can live and if they have any specific diseases that can swiftly kill.

 

[LeanneEllis]

He was a 1.5 cm fry when I got him 2 years ago. Oranda life expectancy is around 15 years so it is not old age. He was 10 inches long (including tail). Not sure what you mean by scientific name???? He was a fresh cold water oranda. There was no disease, parasites or infections on the fish or in the tank. Ammonia was zero, nitrates zero, nitrites zero and PH between 7.4 and 7.8. Perfect parameters. No chlorine either as I use mineralised RO water. Never use tap water in my aquarium. There is no reason he died and the other fish (black Moore and 2 Dojo loaches) are in perfect condition. No marks on the oranda whatsoever.

 

[pwypGlofish]

Well, I guess the only thing you can do is contact an expert to make an autopsy

So sorry about your fish! I guess he was really gentle and sweet, however these things happen sometimes and may not be your fault.