spawn

Extruded egg mass of such egg-laying animals as fish, amphibians, and molluscs.

Spawn is produced in very variable quantities (for example, the ling lays about 150,000,000 eggs, and the American oyster 60,000,000 eggs) and is much preyed upon, even, as in the case of the stickleback, by the female herself. A variety of means have been devised for its protection.

In fish, spawning is the reproductive phase, variously involving aggregation of the fish, courtship, extrusion of eggs and sperm into the water, and fertilization of the eggs. Large migrations may precede spawning, as in salmon and herring. In some groups the spawn is not released, fertilization being internal.

The name is also sometimes given to the mycelium of mushrooms and other fungi, seen as white threads in decaying matter.