1. Salmon Breeding
• The are two species of Coho Salmon are Jacks and Hooknoses – both are male
• The scientific name for Coho salmon is Oncorhynchus kisutch
• They breed in rivers that flow into the North Pacific Ocean
• The adults die after breeding
Hooknoses:
• They fight each other for access to the females
• The winner is able to shed their sperm over the eggs
Jacks:
• They avoid fighting
• Instead, they sneak up on the female to fertilize the egg
Species Depends on Growth Rate:
• Rapidly growing males are able to return to breed after two years, meaning they spawn as Jacks because they are smaller upon returning to breed. Because of their smaller size, they take a sneaky approach to reproducing.
• Hooknose males that grow less rapidly remain in the ocean for an extra year, thus when they return to breed they are much larger. Because of their size, they can’t sneak up on the female without being noticed so they must fight each other.