bioluminescent ocean life

7 Underwater Facts for World Oceans Day

Today is World Oceans Day, a global day of ocean celebration and collaboration for a better future. A healthy world ocean is critical to our survival. Together, let’s honor, help protect, and conserve the world’s oceans!

1. While the Earth’s oceans are known as five separate entities, there is really only one ocean.

2. The ocean contains upwards of 99% of the world’s biosphere, that is, the spaces and places where life exists.

Both above GIFs are from the TED-Ed Lesson How big is the ocean? - Scott Gass

Animation by 20 steps

3. Jellyfish are soft because they are 95% water and are mostly made of a translucent gel-like substance called mesoglea. With such delicate bodies, jellyfish rely on thousands of venom-containing stinging cells called cnidocytes for protection and prey capture.

From the TED-Ed Lesson How does a jellyfish sting? - Neosha S Kashef

Animation by Cinematic

4. Plastics & litter that make their way into our oceans are swiftly carried by currents, ultimately winding up in huge circulating ocean systems called gyres. The earth has five gyres that act as gathering points, but the largest of all is known as the ‘Great Pacific Garbage Patch’ and has grown so immense that the oceanic garbage patch can shift from around the size of Texas, to something the size of the United States. 

From the TED-Ed Lesson The nurdles’ quest for ocean domination - Kim Preshoff

Animation by Reflective Films

5. The 200 or so species of octopuses are mollusks belonging to the order Cephalopoda, Greek for ‘head-feet’. Those heads contain impressively large brains, with a brain to body ratio similar to that of other intelligent animals, and a complex nervous system with about as many neurons as that of a dog.

From the TED-Ed Lesson Why the octopus brain is so extraordinary - Cláudio L. Guerra

Animation by Cinematic

6. Some lucky animals are naturally endowed with bioluminescence, or the ability to create light. The firefly, the anglerfish, and a few more surprising creatures use this ability in many ways, including survival, hunting, and mating.

From the TED-Ed Lesson The brilliance of bioluminescence - Leslie Kenna

Animation by Cinematic

7. Sea turtles ultimately grow from the size of a dinner plate to that of a dinner table. In the case of the leatherback sea turtle, this can take up to a decade. Happy World Turtle Day!

From the TED-Ed Lesson The survival of the sea turtle - Scott Gass

Animation by Cinematic Sweden

nytimes.com
The Deep Seas Are Alive With Light
Bioluminescence is not rare, scientists have learned. It is so common in the oceans that it ranks as one of the planet’s dominant traits.
By William J. Broad

Sternoptyx, a marine hatchetfish whose lower body can glow blue, perhaps to elude predators. Steven Haddock/Monterey Bay Aquarium Research Institute.

Helicocranchia, a genus of tiny transparent squids. Some have light-emitting cells near their eyes. Steven Haddock/Monterey Bay Aquarium Research Institute.

Excerpt:

Over the decades, biologists learned that the creatures of the deep sea use light much as animals on land use sound — to lure, intimidate, stun, mislead and find mates.

The living lights emanated from tiny fish with needlelike fangs, and gelatinous brutes with thousands of feeding tentacles. The sheer variety suggested that bioluminescence was fairly common, but no scientist came up with a measurement of the phenomenon.

Now, 85 years after Dr. Beebe’s pioneering dive, scientists have succeeded in gauging the actual extent of bioluminescence in the deep ocean.

During 240 research dives in the Pacific, they recorded every occurrence and kind of glowing sea creature — more than 500 types living down as deep as two miles. Then, the researchers merged the results into a comprehensive survey.

The result? Most of the creatures — a stunning 76 percent — made their own light, vastly outnumbering the ranks of the unlit, such as dolphins.

youtube

This video doesn’t mention our squid sadly but it’s still a pretty good summation of bioluminescence!

  • Phylum: Mollusca
  • Class: Cephalopoda 
  • Family: Cranchiidae

The Glass Squid spends most of it’s life in partially sunlit, shallow waters where it’s glass-like transparency aids in it’s camoflouge. Many species are bioluminescent and have light organs underneath their eyes which are used to cancel out shadows. The only internal organ visible is a digestive gland which is equivalent to the mammalian liver.

Photograph from: squirrelbasket.wordpress.com

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Violet blanket octopus (Tremoctopus violaceus) is an example of extreme sexual dimorphism in a species: females can be up to 2m in length whereas males are a tiny 1-2cm creatures.
Jewelled Umbrella squid (Histioteuthis bonnellii).The jewels of this squid are bioluminescent photophores that cover its body and provide the most beautiful play of colours in deep see. 

From: Mollusques méditeranéens by Jean Baptiste Vérany (1851)