Signaling

Fish use body posture and movement to send signals to each other. Some of these postures exaggerate secondary sexual characteristics such as jaw size and body height in the case of salmon males. Males signal to females to stimulate them to spawn. Males and females use signals to assert dominance.

An alpha male Chum Salmon gapes
An alpha male Chum Salmon (Oncorhynchus keta) gapes while courting the female just ahead of him signaling his intentions to her as well as threatening two rival and gaping males. As well, another female watches as she is guarding her redd just downstream. Also visible at the top of the frame in this topside view is a school of migrating salmon in deeper water.
Summer topside
The gape threat
Male Coho Salmon (Oncorhynchus kisutch) signaling a threat by gaping. Photographed in situ using a Canon 1Dx camera in a Seacam underwater housing.
Alaska Autumn Class Actinopterygii Coho Salmon Infraclass Teleostei Oncorhynchus kisutch Pacific salmon Phyllum Chordata Power Creek Salmonidae Salmoniformes Salmoninae Sea Sea internal correction lens Seacam underwater housing Silver Salmon South Central Alaska Subclass Neopterygii Teleost United States Vertebrate aggression fish behavior gaping near Cordova threat posture underwater wild wild salmon
A Dolly Varden male being agressive by gaping.
A Dolly Varden (Salvelinus malma) male being agressive by gaping. Underwater image in an Alaska stream during autumn.
Autumn Class Actinopterygii Dolly Varden Dolly Varden Char Dolly Varden Charr Dolly Varden Charr southern form Infraclass Teleostei Phyllum Chordata Salmonidae Salmoniformes Salmoninae Salvelinus malma Salvelinus malma lordi Seacam underwater housing Subclass Neopterygii Teleost Vertebrate aggression fish behavior gaping male behavior male threat posture underwater wild wild char wild charr wild salmon wild trout
Gaping male Sockeye Salmon
Male Sockeye Salmon (Oncorhynchus nerka) schooled alongside Dolly Varden (Salvelinus malma) gapes to sert his dominance among the other males competeing for a female in the school.
Class Actinopterygii Dolly Varden Dolly Varden Char Dolly Varden Charr Dolly Varden Charr southern form Infraclass Teleostei Oncorhynchus nerka Pacific salmon Phyllum Chordata Red Salmon Salmonidae Salmoniformes Salmoninae Salvelinus malma Salvelinus malma lordi Seacam underwater housing Sockeye Salmon Subclass Neopterygii Summer Teleost Vertebrate aggression fish behavior gaping underwater wild wild salmon
Gaping Chum Salmon
A Gaping male Chum Salmon (Oncorhynchus keta).
Chinook Salmon Chum Salmon Class Actinopterygii Dog Salmon Infraclass Teleostei King Salmon Oncorhynchus keta Oncorhynchus tshawytscha Pacific salmon Phyllum Chordata Salmonidae Salmoniformes Salmoninae Seacam underwater housing Subclass Neopterygii Summer Teleost Vertebrate underwater wild wild salmon
Male Cutthroat Trout gaping
Male Searun Coastal Cutthroat Trout (Oncorhynchus clarkii clarkii) gaping during spawning migration is asserting his position in the stream.
Alaska Class Actinopterygii Coastal Cutthroat Trout Cordova Eccles Creek Infraclass Teleostei Oncorhynchus clarkii clarkii Pacific trout Phyllum Chordata Prince William Sound Salmonidae Salmoniformes Salmoninae Seacam underwater housing Searun Coastal Cutthroat Trout South Central Alaska Spring Subclass Neopterygii Teleost United States Vertebrate aggression fish behavior gaping threat posture underwater wild wild char wild salmon wild trout
Male Cutthroat Trout flared throat aggressive display
Male Searun Coastal Cutthroat Trout (Oncorhynchus clarkii clarkii) challenging another fish by using the flared throat aggressive display, which reveals the red slashes giving the species its name.
Alaska Class Actinopterygii Coastal Cutthroat Trout Cordova Eccles Creek Infraclass Teleostei Oncorhynchus clarkii clarkii Pacific trout Phyllum Chordata Prince William Sound Salmonidae Salmoniformes Salmoninae Seacam underwater housing Searun Coastal Cutthroat Trout South Central Alaska Spring Subclass Neopterygii Teleost United States Vertebrate aggression fish behavior threat posture underwater wild wild trout
Gaping Coho Salmon
A male and female Coho Salmon a.k.a. Silver Salmon (Oncorhynchus kisutch) exchange gapes while schooled near spawning habitat.
Autumn Class Actinopterygii Coho Salmon Infraclass Teleostei Oncorhynchus kisutch Oncorhynchus nerka Pacific salmon Phyllum Chordata Red Salmon Salmonidae Salmoniformes Salmoninae Silver Salmon Sockeye Salmon Subclass Neopterygii Teleost Vertebrate underwater
Sockeye Salmon emerging from glacial water
Sockeye Salmon (Oncorhynchus nerka) emerging from glacial water. Gaping male signaling his dominance is at the lead. Aspect Ratio = 1:1.
Class Actinopterygii Infraclass Teleostei Oncorhynchus nerka Pacific salmon Phyllum Chordata Red Salmon Salmonidae Salmoniformes Salmoninae Seacam underwater housing Sockeye Salmon Subclass Neopterygii Summer Teleost Vertebrate underwater wild wild salmon
Gaping female Pink Salmon
Female Pink Salmon (Oncorhynchus gorbuscha) signaling a threat with her gape while a Dolly Varden (Salvelinus malma) lurks on the bottom. Aspect ratio = 1:2.
Alaska Class Actinopterygii Cordova Dolly Varden Dolly Varden Char Dolly Varden Charr Dolly Varden Charr southern form Eccles Creek Humpback Salmon Infraclass Teleostei Oncorhynchus gorbuscha Pacific salmon Phyllum Chordata Pink Salmon Prince William Sound Salmonidae Salmoniformes Salmoninae Salvelinus malma Salvelinus malma lordi Seacam underwater housing South Central Alaska Subclass Neopterygii Teleost United States Vertebrate underwater wild wild salmon
Searun Coastal Cutthroat Trout pair in a small stream
Searun Coastal Cutthroat Trout (Oncorhynchus clarkii clarkii) male signaling a female by his raised head posture in a small tributary of Prince William Sound, Alaska. Aspect Ratio = 2:3.
Alaska Class Actinopterygii Coastal Cutthroat Trout Cordova Eccles Creek Infraclass Teleostei Oncorhynchus clarkii clarkii Pacific trout Phyllum Chordata Prince William Sound Salmonidae Salmoniformes Salmoninae Seacam underwater housing Searun Coastal Cutthroat Trout South Central Alaska Spring Subclass Neopterygii Teleost United States Vertebrate underwater wild wild trout
Gaping Coho Salmon male
To encouage his mate to spawn, a male Coho Salmon a.k.a. Silver Salmon (Oncorhynchus kisutch) gapes in an Alaska, USA stream during the autumn.
Autumn Class Actinopterygii Coho Salmon Infraclass Teleostei Oncorhynchus kisutch Pacific salmon Phyllum Chordata Salmonidae Salmoniformes Salmoninae Seacam underwater housing Silver Salmon Subclass Neopterygii Teleost Vertebrate aggression fish behavior male behavior male gaping nature threat posture underwater wild wild salmon
Dolly Varden spawning pair
A male Dolly Varden (Salvelinus malma) signals the female by extending and quivering his colorful paired fins. Aspect ratio = 4:5.
Autumn Class Actinopterygii Dolly Varden Dolly Varden Char Dolly Varden Charr Dolly Varden Charr southern form Infraclass Teleostei Phyllum Chordata Salmonidae Salmoniformes Salmoninae Salvelinus malma Salvelinus malma lordi Seacam underwater housing Subclass Neopterygii Teleost Vertebrate underwater wild wild char wild charr wild trout
Dolly Varden spawning pair
Dolly Varden (Salvelinus malma) probing her redd as the male sends signals by crossing over and quivering his colorful paired fins . Aspect ratio = 2:3.
Autumn Class Actinopterygii Dolly Varden Dolly Varden Char Dolly Varden Charr Dolly Varden Charr southern form Infraclass Teleostei Phyllum Chordata Salmonidae Salmoniformes Salmoninae Salvelinus malma Salvelinus malma lordi Seacam underwater housing Subclass Neopterygii Teleost Vertebrate fish behavior probing spawning behavior underwater waving wild wild char wild charr wild trout
Keep away!
A female Coho Salmon (Oncorhynchus kisutch) gapes aggressively at an intruding female.
Autumn Class Actinopterygii Coho Salmon Infraclass Teleostei Oncorhynchus kisutch Pacific salmon Phyllum Chordata Salmonidae Salmoniformes Salmoninae Seacam underwater housing Silver Salmon Subclass Neopterygii Teleost Vertebrate aggression fish behavior threat posture underwater wild
Female Coho Salmon probes while male gapes
Female Coho Salmon (Oncorhynchus kisutch) probes while male encouages her to spawn by gaping. Aspect Ratio = 1:2.
Autumn Class Actinopterygii Coho Salmon Infraclass Teleostei Oncorhynchus kisutch Oncorhynchus nerka Pacific salmon Phyllum Chordata Red Salmon Salmonidae Salmoniformes Salmoninae Seacam underwater housing Silver Salmon Sockeye Salmon Subclass Neopterygii Teleost Vertebrate fish behavior probing salmonography.com spawning behavior underwater wild wild salmon
Maturing Coho Salmon
A still bright Coho Salmon (Oncorhynchus kisutch) gapes while holding near a spawning area. Aspect Ratio = 1:2.
Autumn Class Actinopterygii Coho Salmon Infraclass Teleostei Oncorhynchus kisutch Oncorhynchus nerka Pacific salmon Phyllum Chordata Red Salmon Salmonidae Salmoniformes Salmoninae Seacam underwater housing Silver Salmon Sockeye Salmon Subclass Neopterygii Teleost Vertebrate aggression fish behavior salmonography.com spawning migration threat posture underwater wild wild salmon
Pink salmon spawning migration
Potential alpha male Pink Salmon (Oncorhynchus gorbuscha) gaping during spawning migration. Underwater view in an Alaskan stream during the summer.
Chum Salmon Class Actinopterygii Dog Salmon Humpback Salmon Infraclass Teleostei Oncorhynchus gorbuscha Oncorhynchus keta Pacific salmon Phyllum Chordata Pink Salmon Salmonidae Salmoniformes Salmoninae Seacam underwater housing Subclass Neopterygii Summer Teleost Vertebrate aggression fish behavior male behavior male threat posture salmonography.com spawning migration threat posture underwater wild wild salmon
Sneaker male courting
A Pink Salmon (Oncorhynchus gorbuscha) sneaker male courts a female building her redd while the alpha male is away fighting. He is attempting to stimulate the female into spawning using crossing over and gaping as signals. Underwater view in an Alaskan intertidal stream during the summer.
Class Actinopterygii Humpback Salmon Infraclass Teleostei Oncorhynchus gorbuscha Pacific salmon Phyllum Chordata Pink Salmon Salmonidae Salmoniformes Salmoninae Seacam underwater housing Subclass Neopterygii Summer Teleost Vertebrate fish behavior intertidal spawning underwater wild wild salmon
Aggressive posture
Head-up aggressive posture by a male Sockeye Salmon (Oncorhynchus nerka).
Class Actinopterygii Infraclass Teleostei Oncorhynchus nerka Pacific salmon Phyllum Chordata Red Salmon Salmonidae Salmoniformes Salmoninae Seacam underwater housing Sockeye Salmon Subclass Neopterygii Teleost Vertebrate underwater wild wild salmon
Coastal Cutthroat Trout displaying red throat slashes
Coastal Cutthroat Trout (Oncorhynchus clarkii clarkii; in picture at left) displaying red throat slashes while in a staging area prior to spawning. Aspect Ratio = 2:3.
Class Actinopterygii Coastal Cutthroat Trout Dolly Varden Dolly Varden Char Dolly Varden Charr Dolly Varden Charr southern form Infraclass Teleostei Oncorhynchus clarkii clarkii Pacific trout Phyllum Chordata Salmonidae Salmoniformes Salmoninae Salvelinus malma Salvelinus malma lordi Seacam underwater housing Spring Subclass Neopterygii Teleost Vertebrate underwater wild wild char wild charr wild trout
Snout up aggressive posture
Male Sockeye Salmon (Oncorhynchus nerka) challenging another male by raising his snout. Aspect ratio = 3:4..
Alaska Class Actinopterygii Infraclass Teleostei Oncorhynchus nerka Pacific salmon Phyllum Chordata Red Salmon Salmonidae Salmoniformes Salmoninae Seacam underwater housing Sockeye Salmon South Central Alaska 2 Subclass Neopterygii Summer Teleost United States Vertebrate aggression fish behavior salmonography.com threat posture underwater wild wild salmon
Male Sockeye courtship behavior
A male Sockeye Salmon (Oncorhynchus nerka) defending his place with a female (at the far left) with a snout up aggressive posture. Aspect ratio = 1:2.
Alaska Class Actinopterygii Infraclass Teleostei Oncorhynchus nerka Pacific salmon Phyllum Chordata Red Salmon Salmonidae Salmoniformes Salmoninae Seacam underwater housing Sockeye Salmon South Central Alaska 2 Subclass Neopterygii Teleost United States Vertebrate aggression courtship fish behavior spawning behavior threat posture underwater wild wild salmon
Snout up aggressive posture
Male Sockeye Salmon (Oncorhynchus nerka) challenging another male by raining his snout. Aspect Ratio = 2:3.
Alaska Class Actinopterygii Infraclass Teleostei Oncorhynchus nerka Pacific salmon Phyllum Chordata Red Salmon Salmonidae Salmoniformes Salmoninae Seacam underwater housing Sockeye Salmon South Central Alaska 2 Subclass Neopterygii Summer Teleost United States Vertebrate aggression fish behavior salmonography.com threat posture underwater wild wild salmon
Male Coho Salmon doing gaping threat display
Male Coho Salmon (Oncorhynchus kisutch) doing the gaping threat display. Aspect Ratio = 1:2.
Alaska Class Actinopterygii Coho Salmon Infraclass Teleostei Oncorhynchus kisutch Pacific salmon Phyllum Chordata Salmonidae Salmoniformes Salmoninae Seacam underwater housing Silver Salmon South Central Alaska 2 Subclass Neopterygii Teleost United States Vertebrate salmonography.com underwater wild wild salmon
Sockeye Salmon spawning pair
Male Sockeye Salmon (Oncorhynchus nerka) quivering (courtship) a female, which generates surface waves. Aspect Ratio = 3:4.
Alaska Class Actinopterygii Infraclass Teleostei Oncorhynchus nerka Pacific salmon Phyllum Chordata Red Salmon Salmonidae Salmoniformes Salmoninae Seacam underwater housing Sockeye Salmon South Central Alaska 2 Subclass Neopterygii Teleost United States Vertebrate fish behavior male behavior quivering salmonography.com underwater wild wild salmon
Male Sockeye Salmon threat posture
Male Sockeye Salmon (Oncorhynchus nerka) threatening another male by raising his snout. Aspect Ratio = 3:4.
Alaska Class Actinopterygii Infraclass Teleostei Oncorhynchus nerka Pacific salmon Phyllum Chordata Red Salmon Salmonidae Salmoniformes Salmoninae Seacam underwater housing Sockeye Salmon South Central Alaska 2 Subclass Neopterygii Teleost United States Vertebrate aggression fish behavior salmonography.com threat posture underwater wild wild salmon
Male Coho Salmon gaping during spawning migration
Potential alpha male Coho Salmon (Oncorhynchus kisutch) gaping during spawning migration. Aspect Ratio 1:2.
Alaska Class Actinopterygii Coho Salmon Infraclass Teleostei Oncorhynchus kisutch Pacific salmon Phyllum Chordata Salmonidae Salmoniformes Salmoninae Seacam underwater housing Silver Salmon South Central Alaska 2 Subclass Neopterygii Teleost United States Vertebrate aggression fish behavior salmonography.com threat posture underwater wild wild salmon
Pink Salmon (Oncorhynchus gorbuscha)
Pink Salmon (Oncorhynchus gorbuscha). Aspect ratio = 4:5.
Alaska Class Actinopterygii Cordova Hartney Bay Humpback Salmon Infraclass Teleostei Oncorhynchus gorbuscha Pacific salmon Phyllum Chordata Pink Salmon Prince William Sound Salmonidae Salmoniformes Salmoninae Seacam underwater housing South Central Alaska South Central Alaska 2 Subclass Neopterygii Summer Teleost United States Vertebrate underwater wild wild salmon
Sockeye Salmon male gaping threat display
Gaping, a threat display by a male Sockeye Salmon (Oncorhynchus nerka). Aspect Ratio = 1:2.5.
Alaska Class Actinopterygii Infraclass Teleostei Oncorhynchus nerka Pacific salmon Phyllum Chordata Red Salmon Salmonidae Salmoniformes Salmoninae Seacam underwater housing Sockeye Salmon South Central Alaska 2 Subclass Neopterygii Summer Teleost United States Vertebrate aggression fish behavior gaping portfolio salmonography.com underwater wild wild salmon