Wife was doing routine maintenance of a pump and filter and removed a handful of string algae. Noticing some small specks she tossed the algae in a quarantine tank and now she has perhaps two dozen comet fry. She don't need any more comets but finding was interesting. And, why eggs in the middle of summer? Out in the middle of the Nevada desert it is unlikely, but not imposable I suppose, that the pond is contaminated with some other fish.