Fireflies of the Sea

Have you ever seen a firefly? It glows due to something called bioluminescence. Our oceans are full of creatures that use bioluminescence. Why are these creatures glowing? There are actually many different reasons why they glow or flash. They could be calling for help or trying to attract a meal – they might even be trying to lose a predator. Different creatures use bioluminescence in different ways; squids spray bioluminescent ink, whereas other creatures have bioluminescent cells the glow or flash.



There are many different types of animals that glow and for all different reasons. For example, the deep sea angler fish has a small rod above its mouth with a “lightbulb” to attract fish near its mouth so it can eat them. There’s also the vampire squid that shoots out a glowing liquid when escaping a predator to shock it. As a last resort, the deep sea jellyfish flashes when it’s attacked, it does this to call larger predators in hopes they will eat it’s attacker.

Bioluminescence is created by a chemical reaction. This reaction involves at least three ingredients: an enzyme called luciferase, oxygen, and luciferin. The luciferase helps the oxygen bind to the organic molecule called luciferin. The high-energy molecule created by the reaction releases energy in the form of light. To be able to do this it took 50 evolutions or more!



Bioluminescent are found throughout marine habitats, they can be found in the deepest parts of the ocean all the way to the surface. There are so many more types of these creatures that have not been discovered yet. Humans have only explored 5 percent of our oceans and have barely touched the deepest parts. Scientists discover new fish everyday and there are thousand or even millions more to be found.

Click here for a link to lesson plans and activities on bioluminescence.

See bioluminescence in action.

Learn more about bioluminescence in this talk.

The Mystery of the Ocean

giantsquitgraphicfactf320x301You would think an animal the size of a school bus would be easy to find. Yet the giant squid, which weighs over a ton and is over 42 feet in length, is still one of the biggest mysteries of the ocean. Scientists all over the world are trying to learn more about this elusive animal. Part of the reason that so little is known about them is because they live in the deepest parts of the ocean. They are so deep that it takes about 2 hours to go up and down in a submarine. It has only been recently that they have had technology advanced enough to go that deep and it is still very expensive.

A giant squid’s body may look pretty simple – like other squid and octopus, it has two eyes, a beak, eight arms, two feeding tentacles, and a funnel. The eye of a giant squid is a big as a dinner plate. The main part of the body is called the mantle. On the underside of the body is the funnel. The squid pumps water through the funnel to move through the water, to lay eggs, and to squirt ink. Feeding tentacles can catch prey up to 330 feet away. They also have sharp tooth suckers at the end of their tentacles.


Giant suckers

Giant squid feed on deep-water fish and other squid. Once they catch food with the suckers and teeth on their feeding tentacles, they pull it back to their body and their beak. The beak breaks the food down into smaller pieces first and then they use the radula, a tongue-like organ with teeth, to grind it up more. The food then goes into the esophagus, which travels through the squid’s brain, to the stomach. Although giant squid do not have many predators, remains of them have been found in the stomachs of sperm whales.

architeuthis beak 32xx258


It is believed that giant squid live for 3 to 5 years, but this is just an educated guess by scientists. During their life, giant squid only reproduce once. Females release millions of tiny, transparent fertilized eggs into the water in a jellied clump called an egg mass. They need to make lots of eggs because other marine animals quickly eat most of the eggs that are released.

It is believed that the giant squid live in all four of our oceans, but none have ever been seen in tropical or polar regions. They are usually found near continental and island slopes. Although there is so little known about the giant squid, there are multiple studies in progress right now. In 2012, researchers in Japan were able to capture video of a living giant squid for the first time. Using flashing lights to mimic bioluminescent jellyfish, they were able to attract a giant squid to the camera in a submarine. Scientists are learning more and more about these mysterious squid every day.


Architeuthis distribution

Click here for a link to lesson plans and activities on Giant Squid (Architeuthis dux).

The first video of a giant squid ever!

How they found the giant squid.