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SpeciesScientists Discover Mysterious New Fish in the Red Sea – and Have Never Seen It Again OceanEye to eye with Britain's hidden sharks at SharkAdemy - Oceanographic RiversIn October, biologists surveying a New York harbor for invasive fish pulled up a bright yellow one. It wasn't an invasive species at all OceanShedd Aquarium Sends Shark Eggs to Bolster Wild Populations SpeciesA rare fish has been found in Lake Ontario, North America, whose entire body is golden. It is a nati..OceanThe Great Sea Reef Is Fiji’s Wildest Dive, and a New Frontier for Conservation OceanEckerd College professor contributes to designating Biscayne Bay an Important Shark and Ray Area SpeciesRio Verde Grande Survey Identifies Fifty-Three Fish Species Facing Flow Reductions FisheriesAdams River Salmon Run in Thompson-Nicola IndiaHilsa production dropped 26% in five years, fisheries minister tells parliament SpeciesScientists Discover Mysterious New Fish in the Red Sea – and Have Never Seen It Again OceanEye to eye with Britain's hidden sharks at SharkAdemy - Oceanographic RiversIn October, biologists surveying a New York harbor for invasive fish pulled up a bright yellow one. It wasn't an invasive species at all OceanShedd Aquarium Sends Shark Eggs to Bolster Wild Populations SpeciesA rare fish has been found in Lake Ontario, North America, whose entire body is golden. It is a nati..OceanThe Great Sea Reef Is Fiji’s Wildest Dive, and a New Frontier for Conservation OceanEckerd College professor contributes to designating Biscayne Bay an Important Shark and Ray Area SpeciesRio Verde Grande Survey Identifies Fifty-Three Fish Species Facing Flow Reductions FisheriesAdams River Salmon Run in Thompson-Nicola IndiaHilsa production dropped 26% in five years, fisheries minister tells parliament

EveryFish

Jawless fish

Lampreys and hagfish, the only living fish without jaws, survivors of the earliest branch of fish.

Also: Agnatha, cyclostomes

The first fish, over 480 million years ago, had no jaws. Today only two groups remain: the lampreys and the hagfish, together about 120 species. They have long, eel-like bodies, no paired fins, no true bones and a skeleton of cartilage. Lampreys have a round, sucking mouth lined with horny teeth; many species latch onto other fish and feed on their blood. Hagfish live on the sea floor, scavenging dead animals, and can tie themselves in knots. The sea lamprey caused great damage after it entered the Great Lakes of North America.

See also

Cartilaginous fish Bony fish Invasive species

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