Thanks for the feedback. It sounds like I need to intervene.
I suppose it's possible he was just delivered in this tank and he's going to be moved to something more appropriate, but that's not the feeling I get. The tank looked old and I'm not positive there was a filter. I'll have to take a closer look. I clicked on the pictures of the koi, but it doesn't look like him. I wonder if I can get a photo.
We were planning to upgrade to a 20 or 30-gallon tank, so I could donate ours to the class fish. It's still only 10 gallons; which still looks way too small by the recs on that link.
But still better.
Are they temperature sensitive? I worry about keeping the temperature constant in the school after-hours.
I will have to approach this very delicately with dd's teacher. She's a great teacher, but I don't quite know how to approach her. Her class (room size) is small and the tank barely fits on its tiny table.
I'll make an excuse to go to dd's class in the next day or so and get a really good look. It was hard to see exactly what was going on with all the kids around the tank today. I'll keep you updated.
Oh and BTW, we inherited 3 harlequin rasboras and bought 6 more, on the advice of the fish store. They are an awesome business and showed dd all the different possibilities they had for alternatives to goldfish and why they should live in ponds. Then, of course, dd asked if we could build a pond.
Whole 'nother question; we live in NS and have cats in the neighbourhood. But I'd be willing to try...