Yes, what fish are in the main tank where these first appeared?
In the meantime...as the eggs are now "protected" they won't get eaten and should hatch. I would find some dried leaves, you can collect hardwood tree leaves that have fallen to the ground, oak, maple, beech, etc., from a safe place (no pesticides, etc) and lay them out to fully dry after a rinse in warm water. Then add a bunch to this fry holding pen. The leaves will sink in a few days and tons of infusoria will be produced and this is the absolute best food for any fry. You can also buy Indian almond leaves in some fish stores.
You can consider higher fry foods once you know that these are, and if you want them. But the leaves will get whatever fish started off on a very healthy life.