Incredible and Fun Marine Life Facts

Mantis Shrimp Koh Tao - Marine Life Facts
Swivelling eyes gives the Mantis Shrimps nearly 360° vision.

Who doesn’t love knowing more about marine life facts? Especially if you are an underwater diver! So let’s dive deep into some interesting and fun marine life facts that will be sure to surprise you!

Cool Marine Life Facts

A group of dolphins is called a pod.

A group of jellyfish is called a bloom, swarm, or a smack of jellyfish.

While a group of stingrays is a fever of stingrays!

More than one octopus can be called octopi, octopuses, or octopodes. They also have three hearts!

Blue whales and sperm whales are loud! Blue whales have been measured at 188 decibels (dB), while the sperm whale has its communicative clicks recorded at an impressive 230 dB. For comparison, a jet-engine taking off is a usual 150 dB!

Juvenile harlequin sweetlips will swim around, fluttering and bobbing around in a seemingly random motion but there is a purpose to this! They are camouflaged to look like a poisonous flatworm or nudibranch to deter predators.

Seahorses are the only animal where the male gives birth. These creatures also mate for life.

If a manta ray stops swimming, it will sink! Like sharks, manta rays have a cartilaginous skeleton that is very light and saves them energy when swimming around. However, they are still giant creatures that can weigh a tonne!

Whale sharks are not whales! They also have about 3,000 tiny teeth but they don’t use these to eat as they are filter-feeders.

Read More: The Ultimate Guide to Whale Shark Facts

Butterfly fish can produce around 3,000 – 4,000 eggs a day!

Clownfish are hermaphrodites which means that they can be male and female. They are originally born male and have the ability to change into a female. This commonly happens when the dominant female dies, and they need a new female leader!

Sailfish are known to be the fastest fish in the ocean, with speeds recorded over 68 mph (109 km/hr)!

The largest recorded tuna was found in Nova Scotia, Canada, in 1979. It was a gigantic 679 kg (1,497 lb) and 3.7 m (12 ft) long!

Weird Marine Facts

A Starfish has eyespots that can detect light and darkness. These ‘eyes’ are located on the end of each arm which means an average starfish that has 5 arms will have 5 eyes. Whereas, a starfish with 40 arms will have 40 eyes!

The lanternfish is, by far, the most common deep-sea fish. They migrate vertically. During the day they will be located between 300 and 1,500 m (980 and 4,920 ft) deep. Whereas at night they come up from the depths to between 10 and 100 m (33 and 328 ft) deep to feed on zooplankton.

Mimic octopuses are master disguises. They have been observed resembling anemones, mantis shrimp, feather stars, brittle stars, seahorses, crocodile snake eels, jellyfish, giant crabs, stingrays, and even nudibranchs!

Frogfish have quick reflexes. This helps as they do not have teeth and they swallow their prey in one piece! A frogfish can swallow prey that is double its size due to its amazing ability to expand its mouth 12 times its size!

Mantis shrimps can see UV, visible and polarised light. They have up to 16 photoreceptors and can see depth in one eye. Their eyes can also swivel around giving them nearly 360° vision.

Triggerfish will lay their eggs in a sandy nest. The female will then blow water onto the eggs to keep them supplied with a stream of oxygen.

Moray eels secrete a thin, transparent mucus that forms a protective layer over their skin. This helps them glide through the water with less resistance.

Nudibranchs do not usually produce their own chemical defenses. They actually obtain these chemicals from their food sources, such as sponges. Sponges often contain either distasteful or poisonous chemicals in their tissues!

Planaria, a type of flatworm, can be split lengthwise or crosswise to regenerate into two separate individuals!

Salmon are “anadromous” which means they migrate and live in both fresh and saltwater depending on their life and reproduction cycle.

Scary Marine Facts

Sea snakes have incredibly toxic venom. However, lucky for us, their teeth are so tiny that it is usually not long enough to pierce through a wetsuit. They are also very docile creatures. Phew!

Barracudas have two sets of razor-sharp teeth for hunting and ripping its prey. They hunt by sight rather than smell, which is why they can sometimes mistake the glint and shine of a diver’s watch or jewelry for their next meal!

Almost all species of pufferfish contains tetrodotoxin, which can be 1,200 times stronger than cyanide. One pufferfish may contain enough toxin to kill 30 adult men. However, they are very passive fish that will only puff up and expose their sharp spines when threatened.