What term describes the process of fish laying eggs and the young that hatch from them?

The term that describes the process in which fish lay eggs and the young that hatch from them is "spawn." This term captures both the act of laying eggs (spawning) and the specific context of aquatic animals, particularly fish, reproducing. During spawning, fish typically release eggs into the water, which are then fertilized by males, leading to the hatch of young fish, known as fry.

In a broader biological context, fertilization refers specifically to the union of sperm and egg but does not encompass the entire process of laying the eggs and hatching. Brood pertains to a group of young animals born at the same time, generally used for birds or mammals, rather than describing the spawning process itself. Incubation refers to the conditions and period necessary for eggs to mature and hatch, often used more commonly in relation to birds. Thus, "spawn" is the most precise term that directly addresses the complete process being described.