When this slime precursor is exuded from the fish, it rapidly mixes with the surrounding water and expands. The slime threads are tiny but vital to this process and unique to hagfish. Each is 10-17 ...

Lampreys are another form of ancient, blood-sucking, jawless fish also still in existence today ... When being hunted in the sea, they can instantly turn the water around them into a cloud of slime, ...

As for iridescence, river catfish have no scales, but their delicate skin is covered with a protective layer of slime that gives them a shiny glow. These fish are threatened with habitat ...