Jack salmon are actually young Chinook salmon, not a separate species. Their heads have a distinct shape that helps them be identified:
* Smaller and more pointed snout: Compared to adult Chinook salmon, they have a less pronounced, more pointed snout.
* Larger eyes: Their eyes are relatively large compared to their body size.
* Smaller, thinner mouth: Their mouth is smaller and thinner than that of an adult.
* Black spots: Jacks often have dark black spots on their bodies, including their head.
* No hook-like jaw: Jacks do not have the distinctive hooked lower jaw that adult male Chinook develop during spawning season.
You can easily find images of jack salmon online by searching for "jack salmon" or "young chinook salmon."