Columbian Shark Dies Instantly...

I have heard in the past that it is not uncommon for a fish to die of a heart attack, or a stroke, i dont know how they determine what killed a fish unless the do an autopsy but i have heard of fish dying for no reason at all.

maybe when he got into it, he hit the side and got knocked out, then died from bleeding or something.

is the urn open on top or does it just have a hole in the side and no openings for a current to move through it? what kind of substrate do you have? do fish go into that a lot?

this might be weird, but if condiitons were right (no water movement through the urn, an unclean gravel or deep sand underneath) there could have been a buildup of poisonous gases from anaerobic bacteria. that's really all i can think of to cause death so quickly in what seemed like a perfectly healthy animal.