What is the term for a small newly hatched fish?

The term for a small newly hatched fish is "fry." Fry are the earliest stage of fish development after eggs hatch. At this stage, they are typically very small and rely on their yolk sac for nutrition until they are able to swim freely and begin to forage for food on their own.

The other terms refer to different stages or concepts in the life cycle of fish. "Spawn" refers to the process of fish laying eggs, while "fingerling" designates a slightly older stage of development where the fish have grown a bit larger and are starting to resemble adult fish more closely. "Larva" typically refers to the stage of development before fry, when the fish are still undergoing significant transformation after hatching, but are not fully formed or independent yet. Therefore, in the context of fish development, fry specifically denotes the stage immediately after hatchling.