Population Demographics for St Joseph, Minnesota in 2016 and 2015.
Princeton's WordNet(0.00 / 0 votes)Rate this definition: 1  spawn(verb) the mass of eggs deposited by fish or amphibians or molluscs. 2  engender, breed, spawn(verb) call forth. 3  spawn(verb) lay spawn. The salmon swims upstream to spawn.
Egglaying is also what the name suggests: the fish lay eggs instead of giving birth to little fish. As the fish grow, they hatch into fry with an attached yolk sac, and then mature into fish. The process usually takes around a week to 10 days, although it can vary widely.