Lion fish/dead grouper question

[sox59]

Strange question. My aggresive tank has been fine for 18 months w/ no changes of livestock(Been up for 4 years, but no changes in fish in 18 months). It has a large snowflake, yellow tang, Piccaso Trig, Niger Trig, Vio Lion, cat shark, and a Min Grouper(about 10"). Grouper was suddenly dead 5 days ago. Was completely healthy, but suddenly dead. His body looked as if he was a stuffed large mouth bass or something, meaning his mouth WIDE open and gills spread as far apart as possible, almost in an aggresive pose. He was fine in the morning, and just dead when I came home for lunch from work. Anyways, water verything is fine, and I was wondering if it is possible the lion could of poisoned him? I have seen trhe lion(about 12" long) at rare time sting a fish during feeding quarrell, and they kinda shake as if electrocuted then hide for a brief time but are generally ok. Is it possible the lion stung him multiple times in an attack? Do large specimens indeed die from stings? Sorry to ask a dumb question, but I just got a new grouper specimen, and besides my niger, it is my fave fish in the tank, and I dont want to lose another one, and if need be will bring the lion to the store to be placed. Thanks in advance!!
-Tim

[Geoff]

from your description of the death i think it was natural causes and not stung. it may have just had a heart attack or something along those lines. wide open mouth is usually a sign of gasping, but with no obvious marks from stings, they would show up, then i would think something more natural.

either way sorry for the loss. it sucks to loose a fish that you have had for such a long time.

G~

[sox59]

Thanks Geoff!! I did inspect his body carefully and couldnt find any wounds, but then I also thought the sting mark might be to small to detect. Anyways, I feel better knowing it was just maybe his "time" is all.

And incidently I meant no changes in tank in 8 months, grouper was the last addition. A LFS stray no one wanted due to his huge size.

[Geoff]

more likely than not the sting mark would be visible. lionfish are not super venomous. they are more interested in deterring than killing. in most cases deterring venom is weaker than those venom used to get food.

since the grouper is a stray there is no way of knowing its age, so it could very well have been fairly old already.

another possibility could be that the diet could have changed for the worse and caused internal problems. not likely, but always something to think about if you did feed a varied died.

G~

[Loverotties]

Hows your oxygen levle in your tank?But I think it's old age to.But a bigger fish with low oxygent can kill him too.