Explore the unique hook-like structure that develops in male salmonids during spawning season
Learn MoreMeet our spectacular featured fish and their impressive kypes
Meet "Thunder," a 15-year-old male brown trout from Lake Windermere with one of the most impressive kypes ever documented. This enormous fish has survived multiple spawning seasons, causing his kype to grow larger each cycle, now extending nearly 4cm from his lower jaw.
"BTK" is a striking male salmon recently caught in the Kenai River, named for its brilliant golden-orange hue that resembled pure gold — earning it the nickname after Bitcoin. This powerful fish displays a sharply hooked kype and broad body, both clear indicators of dominance. Its aggressive behavior and commanding presence suggest it holds alpha status within its spawning group.
"Saber" is a renowned Atlantic Salmon whose unusually curved kype resembles an ancient sword. This 5-year-old male has developed a kype with a dramatic 45-degree upward curve, making him instantly recognizable to researchers tracking spawning behavior in the Kennebec River.
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Learn what kypes are, how they form, and their important role in reproduction of salmonid fish species.
Learn MoreExplore the different species of fish that develop kypes and learn about their unique traits.
View TypesDive into scientific studies and the evolutionary significance of kypes in fish species.
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