Their bodies are divided into two parts, the body and the head. Shrimp pose very little threat to other animals but are prey to many species including humans. They are found in every ocean in the world.
Brittle Stars (Ophiuroids) are closely related to Starfish. They are found in most parts of the world and a few species are even adapted to brackish water. The underside of the disk contains five toothed jaws from skeletal plates that they use to scavenge the ocean floor for food. Like starfish, brittle stars can regenerate lost limbs.
Rat tails (Grenadier Fish) are the most abundant species found living just above the bottom of the sea floor. They have big heads and thin tails. They swim slowly with their heads angled down into the current looking for food.
Umbrella octopuses (Opisthoteuthidae) have a web of skin between the tentacles. They swim up above the ocean floor, spread their tentacles looking like an opened umbrella and collect food as they float down.
The helmet jelly (Periphylla Periphylla) is found in every ocean of the world except the Arctic at depths as deep as 7000 meters. They are 90% water and the rest is tissue and a gelatinous mass. They light themselves from within with bioluminescence.
Acorn worms (Enteropneusta)
have no bones, no eyes and no brains with soft and gelatinous bodies. They crawl over the surface of the mud slurping the sediment and excreting a trail behind them.