Goldfish (sarasa comet)
I had a couple of goldfish in an outside tub for mosquito control; as the weather warmed up it became clear that the fish were a pair since one of them got all tubercle-y. I brought them inside (where it was warmer still) and put them in a 15-gallon tank over a grid and soon the tank was full of nice big eggs.
The giant eggs gave me a good change to take some photos with my not-very-high-res microscope.
A few of the fry came out gray and then developed color, so I took for granted that the rest of them would eventually color up — I sold and traded a lot of young, gray fish which I now realize probably should’ve been culled. I hate to cull and I’m kind of stunned that the world is so full of goldfish knowing that they’re only producing 5% quality fry after every spawn.