The marine biome is the biggest biome in the world covering about 70% of earth. There are two main types of marine biomes saltwater and freshwater. Marine saltwater biomes can be found in oceans, seas, and other bodies of water that have high salt concentration. Their are three types of saltwater biomes coral reefs, open ocean, and estuaries. Freshwater biomes can be found in lakes, rivers, and streams. Due to how large the ocean is we separate the marine biome into 4 levels euphotic, bathyal, abyssal, and hadal.
Sperm Whale
Sperm Whales are the largest apex predator alive on earth. Male sperm whales average length is 52 feet long and weigh as much as 40 tons. Female sperm whales average around 36 feet in length and weigh around 17 tons. The largest sperm whale ever recorded measured 79 feet long but it is belived that male sperm whales can grow to a length of 91 feet long and weigh around 150 tons. Sperm whales mostly eat squid, shark, skates, and fish but will consume just about anything smaller than them. Sperm whales are listed as endangered but they have no major threats since whaling is now illegal. The only real threat to female and baby sperm whales are Orcas better known as killer whales.
Mantis Shrimp
Mantis shrimp are sea crustaceans that live between 30 and 100 feet below sea level. They often create U-shaped burrows near coral reefs on sandy and gravelly areas. Mantis Shrimp can grow up to 38 cm in length. They can live for 3 to 6 years old and have a gestation period of 9 to 60 days. Mantis shrimp have a very powerful punch and can punch with speeds up to 60 miles per hour. Due to their punch they can kill prey larger than itself mostly feeding on gastropods, crabs, and mollusks. fun fact mantis shrimp have 16 color receptors in their eyes allowing them to see 12 primary colors where as humans can see only 3 primary colors.
Orca
The Orca or better know as the killer whale is the worlds most dominate apex predator not including humans. Not only are they powerful they are also smart with an intelligence equal to a 15 year old human. Killer Whales can weigh up to 13,300 lbs and grow to a length of 27 feet. The largest recorded killer whale was 32 feet long and weighed 22,000 lbs. Orcas are social animals and live in groups called pods. Killer Whales mostly feed on fish, squid, and shark but they can attack and will eat anything in the ocean using unique hunting tactics excluding male sperm whales.
Octopus
The Octopus is a soft-bodied, eight-limbed mollusc that is found in a wide range of depth anywhere from 660 feet deep to 13,100 feet deep. The largest octopus is the giant pacific octopus with an average size of 16 feet long and weighs around 130 lbs. Octopuses are carnivores and mostly eat crabs, clams, snails, fish, and will eat other types of octopuses. All octopuses have venom of varying levels of toxicity which they inject using their beak. Octopuses use their suction cups on their tentacles to grab on to prey, manipulate objects, and anchor themselves to the sea floor.
Sunflower Sea Star
Sunflower Sea Star also know as the sunflower starfish is a starfish that lives on the sea floor. They typically have around 16 to 24 limbs and each limb can grow to 3 feet long. They are one of the largest known sea stars and can weigh 14 lbs. They are carnivorous and feed on sea urchins, fish, mussels, clams, sea cucumbers, gastropods, and sand dollars. fun fact sunflower sea stars can swallow an entire sea urchin, digest it, and eject the urchin's shell. One more fun fact is they don't have blood instead they pump saltwater throughout their bodies. This is also the reason why they can't survive in freshwater.