This might be the archetype Rhinogobius, but I had some trouble getting the eggs to hatch — too much fungus. Eventually I left a male alone in a tank with the eggs and kept an eye on him. Once he left the cave on his own I removed him, and the next day there were fry all over.
This is one of many Rhinogbius species which has fully-formed, benthic fry. Miniature gobies, right out of the gate.
Spawns were large from this species but I lost a tankful of young adults due to (I think) elevated nitrate levels. I don’t tend to worry about nitrates in tanks without invertebrates, but this species turns out to be pretty sensitive.