That has to be the most frustrating thing in the world.
I was on a submarine in the Navy. A submarine does some interesting things to the water as it moves and dolphins, being the adrenaline junkies that they are, loved to play in these fun new currents. As a sonar tech, I got to listen to them playing, whistling and clicking at each other like kids at recess. Sometimes it made me feel like the kid who broke his leg right at the start of summer vacation.
Ecologist swimming in! Me too. What a beautiful gif.
The flickering or flashing we're seeing is a warning. It says "Predator, I know you're here! Don't try anything."
Cephalopods can change the color and texture of their skin! It all starts with the humble chromatophore. Chromatophores are cells that reflect light and hold pigment and are found just below the skin. To contrast, mammals and birds have melanocyts. Amphibians, fish, reptiles, crustaceans and some insects also use chromatophores to change their coloring.
Chromatophores contain a small sack full of pigment (black, brown, orange, red or yellow) which can stretch. If stretched out the color will be brighter, if retracted the color will appear more dull. Aside from chromatophores some cephalopods also have iridophores and leucophores. Iridophores have stacks of reflecting plates which create iridescent colors (greens, blues, silvers and golds) which you can see in of Loligo paeli. Leucophores mirror back the colors of the environment, helping the animal blend in with its surroundings.
Aside from mesmerizing prey and camouflage cephalopod colors are also used to attract mates and warn potential predators or rivals that the organism should not be messed with. For example male Caribbean reef squid (Sepioteuthis sepioidea) turn red to attract females and white to repel other males. Interestingly they can actually split the coloration of their bodies down the middle to attract a female on one side and repel a .... Another example, Humboldt (Dosidicus gigas) squid will flash red and white to warn predators.
There was a study in 2015 where scientists strapped cameras onto Humboldt squid to try to decode the communication. I didn't see anything super conclusive in the article, but I would assume they are working on it. It's a really great topic.
Some cephalopods can change the texture of their skin by manipulating muscular hydrostats. Hydrostats can change shape by squeezing some segments to create extension others. Our tongues have muscular hydrostats which allow us to stretch it out. According to a paper published in 2014:
The octopuses [in the study] had three dedicated types of muscles that control their on-call skin protrusions, or papillae. One set are shaped in concentric circles to lift the skin vertically away from the body. Another set pulls this form together, to determine the shape—whether it will be a round bump or tall spike. And a third group seems to pull the raised section back toward the surface, spreading out its base.
More on that in this Scientific American article.
Edit - Folks are asking how they know what colors to change. We actually are not sure. There was a great Mental Floss interview with an aquarist:
Good question, and one that researchers are still trying to answer. They know Cephalopods (octopuses, squids, and cuttlefish) match their skin to their surroundings using their eyesight. But what’s perplexing is that octopuses are actually colorblind. It’s possible they can distinguish between different polarization of light better than humans can, but the exact method for how they identify color is unknown.
Also, not Unidan! I'm a woman (Uni is a guy) and I've been around and answering comments and questions (on another account /u/Alantha) at the same time and with Unidan. He's a great guy. We'd bounce comments off of each other before he was chased out. There are many many scientists who are happy to talk about their profession and saying we are all Unidan is insulting. We all went to school, worked relevant jobs, maybe published research or taught or whatever. We worked hard and continue to work hard and deserve to be our own people. Calling every scientist who pops in Unidan is lazy and old hat. Leave the dead horses alone.
I realized I came here to see wtf that thing was he's napping on. I'm a bit early though, someone help me out.
Edit: Barrel Sponge, according to u/Aurify.
This some Native American vision quest shit.
Is this supposed to elicit fear in human beings? Because it's working
It's so damn majestic. Like the king of those things they rode from Avatar
Ecologist swimming in! As much as I love the ocean, I'd also be a little freaked out surfing at night.
This beautiful bioluminescence is caused by phytoplankton. There are two main classes of phytoplankton; dinoflagellates and diatoms. Dinoflagellates are our bioluminescent phytoplankton! A common species is the Noctiluca scintillans, commonly known as the sea tinkle (I know, it's adorable). . The bioluminescence is produced throughout the cytoplasm by a luciferin-luciferase reaction in organelles called scintillons.
As I am sure you know, some marine animals also bioluminesce! Common examples are:the squid Abralia veranyi various species of lantern fish angler fish species googly eyed glass squid (Teuthowenia pellucida) vampire squid (Vampyroteuthis infernalis) many many jellyfish or jellies (both words are still used, obviously they are not fish); Aequorea victoria, Aurelia aurita, Bolinopsis infundibulum, etc.
For more information on bioluminescence check out Smithsonain's page on it.
These guys are literally 🔥!
If you are looking to experience this yourself check out the following beaches:The Blue Grotto, Malta (Photo) Bioluminescent Bay, Puerto Rico (Video) San Diego, California (Video) Navarre Beach, Florida (Photo) San Juan Island, Washington (Photo) Toyama Bay, Japan (Photo caused by squid!) Matsu Islands, Taiwan (Photo) Halong Bay, Vietnam (Photo) Jervis Bay, NSW, Australia (Photo)
I doubt anyone in this sub would care too much but that is actually wake surfing. Wakeboarding is more like snowboarding.
Polar bear is having such a "Fuuuuuuuck yeeeeeeessss! This is what I'm about!" moment.