3 strange animals on the ocean floor that you have never seen before

Leptocephalus larvae

The early stages of the life cycle of oceanic animals are usually very different from their adult form.  This leaf-like leptocephalus larva eventually turns into an adult eel and its body shape changes.

Having a thin and transparent body as a larva may help this creature to survive during development and escape from predators.  Because larvae and adults look so different, larval forms were often described as different species of adults, until marine biologists realized they were different stages of the "same" life cycle.

Sapphire flippers

Copepods are small crustaceans, usually a millimeter or two in size, and are often eaten by deep-sea fish such as cottontails and red lampreys.  Most pinnipeds eat microscopic algae that grow near the ocean's surface, and their feces and dead bodies help transport carbon to the deep seabed.

But sapphire pinnipeds are different: Females live as parasites inside wandering jelly animals called salps, while colorful males swim freely in the ocean.  Males have small crystalline plates in their skin that reflect blue light and give them a shiny appearance.

Cotton tail fish and Boxer eel

Cottontail fish and Boxer eel have elongated, thin and ribbon-like bodies.  The body length of cotton tail fish is about 30 cm and the length of its thread is twice the length of its tail.  Its other name is the "tube-eye fish" because of the binocular lenses of its eyes, which it uses to detect the shadows of its prey in the twilight zone.  The tube-eye fish is so unusual that it is the only species in a complete taxonomy.

Boxer eels reach 1.5 meters in length and feed in the water by sweeping their elongated jaws, grabbing the remains of crustaceans with their fine teeth.