General terms:
* Fry: This is the most common and general term for a young fish, especially when it's just hatched and still has a yolk sac.
* Larva: This term is used for fish that hatch from eggs and have a larval stage, which is distinct from the adult form.
* Juvenile: This term is used for a young fish that is beyond the larval stage but hasn't reached adulthood yet.
Specific terms:
Some species have specific names for their young, such as:
* Alevins: Young salmon and trout
* Walleye fry: Young walleye
* Bass fry: Young bass
The term used can also depend on the context. For example, you might call a small, newly hatched fish a fry, but you might call a larger, more developed fish a juvenile.