‘Neon green rasbora’
These are incredibly tiny, similar in size to Boraras but they’re more active swimmers and very conspicuous with their bright colors.
I spawned these in a very hands-off manner; I kept a few adults in a 3-gallon tank with moss. A week or two after I removed the adults a handful of fry showed up.
Raising these in large numbers would be an interesting challenge, maybe requiring rotifers or paramecia as food.