The male Sockeye Salmon (Oncorhynchus nerka) of the spawning pair being aggresive by gaping, Southcentral Alaska

Underwater view of a gaping male pink salmon (Oncorhynchus gorbuscha) in Hartney Creek near Cordova, Alaska in the summer; Alaska, United States of America

Underwater view of a pink salmon (Oncorhynchus gorbuscha) spawning pair with an aggressive sneaker male gaping in Hartney Creek near Cordova, Alaska in the summer; Alaska, United States of America

Chum Salmon (Oncorhynchus keta) spawning migration in an Alaskan stream during the summer.

Animals

Coho Salmon (Oncorhynchus kisutch) spawning pair in an Alaskan stream during autumn, Southcentral Alaska

Coho Salmon (Oncorhynchus kisutch) in the act of spawning in an Alaska stream during autumn.

A Pink Salmon (Oncorhynchus gorbuscha) male comes alongside and quivers a female who is probing her redd in an Alaskan intertidal stream during the summer.

A Sockeye Salmon (Oncorhynchus nerka) jack courts a female in the absence of the alpha male, Southcentral Alaska

Male Coho Salmon (Oncorhynchus kisutch) responding to the female's probing by gaping, underwater view in an Alaskan stream during autumn.

Headshot of a Coho Salmon (Oncorhyncchus kisutch) alpha male (foreground) and his mate reflected in the the shallow water of their spawning habitat in an Alaska stream during late autumn.

Underwater view of a sockeye salmon (Oncorhynchus nerka) spawning pair and a challenger male in Power Creek near Cordova, Alaska in the summer; Alaska, United States of America

A male Pink Salmon (Oncorhynchus gorbuscha) among others of the same species and Dolly Varden Charr (southern form; Salvelinus malma lordi) form a dense school at the bottom of a deep pool during their spawning migration in an Alaskan stream during...

A Sockeye Salmon, also known as Red Salmon (Oncorhynchus nerka) pair in the act of spawning in an Alaskan stream during the summer; Alaska, United States of America

Sockeye Salmon, also known as Red Salmon (Oncorhynchus nerka) spawning pair in an Alaska stream during the summer, South-central Alaska; Alaska, United States of America

Sockeye Salmon, also known as Red Salmon (Oncorhynchus nerka) spawning in an Alaskan stream during the summer. Two competing males are lurking nearby, one is visible at the right edge of the frame and the other, a jack or precocial male, is visible...

Alpha male Pink Salmon (Oncorhynchus gorbuscha) gaping during spawning migration, Alaska