The Open Ocean reaches from the coasts (neritic areas) to the middle of the ocean (ending where deep sea zones begin), and is the largest area of marine biomes. Every living thing in the ocean must have a way to swim or float to survive, but there is still a vast variety of different types of creatures that live in the open ocean biome.
Examples of Creatures That Inhabit the Open Ocean Biome:
Killer Whale (Orcinus Orca) - The Killer Whale, also known as the Orca, is actually a member of the dolphin family, and is the largest in it. They are located worldwide, especially in cooler seas, but also in warmer tropical seas. Though all Killer Whales are carnivorous, their diets vary widely depending on their environment, ranging from mostly fish to marine mammals like seals and walruses. Killer Whales are the apex predator of the ocean, the top predator of an environment that has no predators of its own.
Sea Turtle (Chelonioidea) - Sea Turtles are present in every ocean except the Arctic Ocean, and live around coral reefs or other rocky areas close to shore. Sea turtles live on average around 80 years. Decades pass before a turtle reaches sexual maturity, and when they do the mother returns to land to nest at night, sometimes back to the beach where they were born. Because Sea Turtles take so long to develop sexually, and often have particular mating rituals, every species of Sea Turtle is threatened or endangered.
Sponge (Axinela Polypoides) - One of the simplicist multicellular animals, sponges have no nervous, digestive, or circulatory systems. Instead, the sponge relies on constant water flow through pores to obtain food and oxygen and remove waste products. Sponges are sessile, meaning they do not move around, but instead attach themselves to objects in the ocean. Sponges are famous for their ability to regenerate, but most do reproduce sexually, releasing their sex cells into the water to be absorbed by another sponge.
Sea Star (Asterias Rubens) - Sea Stars, or Starfish, have very spiny skin with many bumps covering the hard surfaces of their bodies. Some bumps absorb oxygen, others are for cleaning itself, and others protect against other organisms like barnacles from landing on its surface. Suckers on the end of its feet help it hold prey and hold onto rocks and other surfaces, and it also has tiny tube feet underneath its arms to improve mobility. A Sea Stars mouth is actually located on the underside of its body, and typically feeds on small mollusks.
Jellyfish (Eutonina Indicans) - Jellyfish do not have digestive, central nervous, respiratory, or circulatory systems. A jellyfish's life span can range from a few hours to a few months, depending on the species. The transparency of jellyfish makes them almost invisible in the ocean and is a great method of self-protection, and jellyfish can be found in every ocean and ocean biome.