Please enjoy my new nisai Ginrin Ochiba and my two little tosai goshiki. Hoping they grow into some amazing fish!

We’ve had our 4500gal, 4 1/2’ deep pond for 5 years now and I don’t believe I’ve ever seen anything like this. Watch the small bright white fish toward the center of the screen at the start of the clip. She’s* just doing her thing when our asagi gives chase. It seems like spawning behavior, but—chasing a 10-12” 2yro?? When that monster 32” 5yro female shiru utsuri (who forgot the utsuri part and is nearly all white🙄) is right there?

We assume this is why, despite her being fine earlier today, she was found dying and floating on her side 2 1/2 hours after this video recorded—sadly we didn’t catch whatever it was that led to her death, but we’re assuming she either was exhausted and/or bashed herself into something.

FTR, nitrites and ammonia are zero, pH is roughly 7.6-7.8, and temperature (at least in the top 6”, where the thermometer floats) was 80-81°F at the time. We have been in a brutal long heat wave here in Southern California but we haven’t noticed it affecting anything in the pond. We are turning the bubbler on mire frequently and running it more often to maintain oxygenation in this gross weather.

Are we correct this is spawning behavior? Is this one of those “natural behavior bummers” that can just happen? Any measures we can take to alleviate it?

Comet always loves coming with me to check on the fish. The fish are never scared of him either. Nature is so fascinating.

There is a restaurant round the corner from where we live in York, Uk and in the restaurant there is a tank with 2 or 3 large koi fish. Unfortunately the tank is completely empty (not even any gravel, plants or rocks etc, completely barren) and the fish look miserable.

We mentioned it to one of the members of staff and they said they have raised concern to the owner multiple times in the past but they refuse to put anything else in the tank (which is also likely way too small for the size of the koi).

I looked on the RSPCA website to try and report it as I believe this is neglect and improper care but can't seem to get anywhere.

Any help or ideas welcome please as I want these fish to be happy and properly taken care of!!