Swim-up fry. That's the fish hatchery jargon for fry with developed mouth, intestine, an inflated swim bladder, and ready to eat real food. It was obvious that's what they were this morning because they were all dating around instead of hanging out on the substrate. I was off by 12 hours in guessing they would be ready to eat tonight.
This guy is 117 to 124 hours old at 24 C. It has already eaten and has a full gut. The greenish tint on the dorsal side appears yellowish on an otherwise clear fish in real life. It appears the spawn is 100% white babies. The male's line has not thrown even a hint of sumi in three generations but I wasn't sure about the female.
The zooplankton was already OK, but I boosted it a little from other ponds to get a solid 10/ml of rotifers and ciliates of appropriate size. If I had ranskye's large ponds, they could be stocked with about 50 to 100 liters per fry. At that density, you can walk away from them and come back in 6 weeks to a bunch of hardened fish ready to cull. That is real koi farming.
I am cramped for space. If the fry were spread out among the available small ponds, they would only have about 8 liters per fry. At that density, they would graze the zooplankton down to a level where it cannot regenerate itself fast enough (an "eat-out") and the fry would then starve. So, I have them in a single small pond with about 1 liter/fry and 5-6 other small green water ponds which are just for making zooplankton - zooplankton reactors. I cannot walk away and will have to fuss with them every day, doing zooplankton counts and moving plankton to the fry pond.
An advantage of this approach is that it's possible to make space available for another spawn if needed. We have some lionhead goldfish which have ovulated and will probably spawn this week so a pond will be given over to them if and when.
-steve