Marine Biology Facts

The giant squid has the largest eyes in the world.

Dolphins sleep with one eye open!

The most powerful electric eel is found in the rivers of Brazil, Columbia, Venezuela, and Peru, and produces a shock of 400-650 volts.

A blue whale's aorta (the main blood vessel) is large enough for a human to crawl through.

More than 90% of shark attack victims survive.

After being in captivity for 23 years, the orca from Free Willy, Keiko, was set free in 2002. Weeks later, he appeared at a Norwegian fjord apparently seeking human contact and even gave rides to children on his back.

A bluefin tuna can swim at speeds up to 40 miles per hour, making it one of the fastest fish in the ocean!

Dolphins have names for one another.

Blue whale hearts weigh about 400 pounds and are roughly the size of a small car. Their aorta is so large that a small human could crawl through it.

Whales and dolphins can't taste anything other than salt.

Before making Finding Nemo, the animation gurus at Pixar Studios had to take a graduate class in fish biology and oceanography.

Parrotfish make themselves a kind of mucus 'sleeping bag' which masks their smell from predators and keeps parasites away.

A jellyfish no wider than a fingernail cannot die of old age. When Turritopsis dohrnii gets old, starving, or injured, its adult cells transform and it shrinks back into a polyp - the larval stage it grew from years earlier. Then it grows up all over again, and can repeat the loop indefinitely. That makes it biologically immortal. Scientists only noticed in the 1990s, when aging adults kept reverting in their tanks instead of dying.

An octopus is less an animal than a separate experiment in intelligence. It has 3 hearts, blue blood (copper-based, not iron), and around 500 million neurons - as many as a dog - but most of them sit in its 8 arms, which can taste, decide, and act on their own. Scientists treat it as the closest thing to alien biology on Earth, and it can even edit its own RNA. When it jet-swims, its main heart stops beating.

When ocean waves glow electric blue at night, the light comes from millions of living creatures. Dinoflagellates - microscopic plankton - carry a chemical called luciferin that flashes the instant water is disturbed. It is a defense: the burst of light summons predators of whatever is eating them. Mosquito Bay on Vieques, Puerto Rico holds the Guinness World Record for the brightest bioluminescent bay, with 700,000 glowing organisms per gallon.