Sexual Maturity: King salmon typically reach sexual maturity at an age between 3-5 years for males and 4-6 years for females. However, variability exists based on regional differences and specific stock characteristics.
Migration Timing: King salmon are anadromous fish, meaning they spend part of their lives in freshwater and part in saltwater. For reproduction, they undertake an upstream migration from the ocean, often during late spring or summer, to their freshwater natal rivers or streams.
Spawning Grounds Selection: Selecting suitable spawning grounds is crucial. These grounds include areas with clean gravel or cobble substrates, cool, well-oxygenated, and flowing water, and cover such as boulders or woody debris for shelter.
Pair Formation: Upon reaching the spawning grounds, male and female king salmon pair up for reproduction. The female, also known as a hen, digs a nest, called a redd, in the gravel. The male, referred to as a jack or cock, stays close to guard and defend the territory from other males.
Egg Laying: Once the redd is prepared, the female begins to deposit large, orange-colored eggs into the nest. Simultaneously, the male releases milt, which contains sperm, over the eggs to fertilize them. This external fertilization process is common among salmon species and occurs multiple times with different males and females.
Nest Cover: After egg deposition, both female and male king salmon participate in covering the nest with gravel. The eggs will remain buried and incubate in the gravel until they hatch.
Parental Care: King salmon do not provide direct parental care after spawning. They leave the eggs and the newly hatched fry (young salmon) to fend for themselves. The parental role ends with the completion of spawning.
Development: The eggs will develop and hatch into alevins, which remain sheltered in the gravel for a period of time, absorbing the yolk sac for nutrition. Later, they emerge from the gravel as free-swimming fry and transition to feeding actively in the river.
Ocean Migration: As juvenile salmon, they spend a few years in their freshwater habitat, growing and adapting to the river's conditions. Eventually, they undergo a physiological transformation called smoltification and prepare to migrate back to the ocean. This migration is part of their life cycle, and they'll return as adults once more to complete the reproductive process.
It's important to note that the specific timing, behavior, and details of reproduction may vary among different populations of king salmon found across their geographic range. The life cycle and migration patterns can be influenced by genetic and environmental factors.