Everybody loves Shark Week and the fascinating glimpses it gives us of the turmoil of life raging beneath the ocean’s tranquil surface. But sharks, though indisputably awesome, aren’t the only captivating denizens of the deep.
This planet’s seas are vast, mysterious, and impregnated with the primal beauty of an exploding star, a world both dangerous and sublime. Nobody looks at an ocean and says, “I’ve seen better.” Every piece of undersea life offers something spectacular hidden in a barnacle-encrusted niche well beyond the searching eyes of normal mortals. But if you look in the right place at the right time, magic happens.
10 Jellyfish Lake
One of the world’s most surreal marine migrations happens every single day on an uninhabited island in the South Pacific. Palau’s Jellyfish Lake is one of close to 70 similar bodies of water on the archipelago. Each of those lakes was once connected to the sea, but it’s believed that they were cut off about 12,000 years ago by changing sea levels. In these isolated pockets of water, certain species have learned to thrive by their own rules. That’s why a few of them, like Jellyfish Lake, are packed tighter than a jar of pickles with jellyfish.
From dawn until dusk, nearly 13 million golden jellyfish (Mastigias sp.) travel from one end of the lake to the other, then back again in a daily spectacle that most of us have only seen in Finding Nemo. Why? They’re following the Sun. The golden jellyfish in these lakes have developed a symbiotic relationship with a type of zooplankton known as zooxanthellae. These algae-like critters live inside the jellyfish’s tissues and photosynthesize sunlight into energy that the jellyfish can use. So every day, starting bright and early, the swarms of jellyfish head east from the western edge of the lake to catch the first rays of sunlight, then track its arc all the way westward again. There, just beyond the shadows cast by the trees, they settle in for the night and wait for day to break once again.
Interestingly, there’s another factor in this migration, one which might have caused it in the first place. The shores of the lake are packed with white sea anemones that will happily snag a passing jellyfish, but these immobile creatures only grow in the shade. If the jellyfish stay in the light, they’re safe, but straying too close to the shadows virtually ensures a quick, brutal end.
9 Squid Giving Birth
Squid can be found in oceans all over the world. There are over 300 distinct species of squid, which range in size from the diminutive pygmy squid to the fan favorite colossal squid, believed to be the largest invertebrate on the planet. And while many of those species reproduce by laying eggs in bundles strewn across the ocean’s floor, the black-eyed squid (Gonatus onyx) takes a more motherly approach.
For the entirety of gestation, the female black-eyed squid carries a massive black sac filled with up to 3,000 miniscule babies. But although the egg pouch looks like a big burlap sack, it’s closer to a beehive—the pulsating sack is a flexible hollow tube with two walls which contain a crisscrossing membrane that grows in a honeycomb pattern. Each of those honeycomb cells holds a single, tiny squid. The mother holds the egg sac in place with hooks on her arms, every now and then shaking it to flush fresh water through the cells.
She does that for up to nine months, and when the infant squid are ready to go out into the world, magic happens. Like the birth of a galaxy, thousands of babies, glowing in the light of the camera, shoot out of the bottom of the tube and radiate away from the mother into the open water.
8 Octopus Hunting On Land
It’s simple fact of life that staying on land vastly limits your chances of death by octopus. Although octopuses are notoriously efficient underwater killers and some of the most intelligent sea creatures we’ve ever seen, their domain rests firmly within the salty realm of the ocean. This short video, taken in Yallingup, Western Australia, shows how little we know.
Like an alien bursting into our world from a parallel dimension, the octopus appears out of nowhere, chases a crab across a rock, and then drags it kicking and screaming back underwater, all in the space of seconds. Octopuses do breathe with gills, but while this is certainly uncommon, it’s a hunting tactic that has been observed before.
Seeing it happen before your eyes is certainly unsettling, but even more unsettling is what you don’t see. After an octopus like this one catches a crab, it pierces the crab’s shell with its beak and liquefies its innards with a special enzyme. Then, once the crab’s body has been reduced to goop, the octopus simplyslurps the protein milkshake out of the shell.
7 Shark Perspective
Most people would rather chop off a toe than get close to a hammerhead, much less wrangle one and strap a camera to its back, but that’s exactly what Andy Casagrande did in July 2015. Casagrande is a filmmaker for National Geographic and a familiar face on Shark Week. He’s made a name for himself with stunts like hand-feeding a school of sharks and messing around with great whites, often combining entertaining camera perspectives with footage that actually helps researchers understand the habits and movements of some of the ocean’s most formidable predators.
And the hammerhead is definitely a uniquely formidable predator (though not usually to humans). Their cephalofoil—the hammer-shaped head—contains two special organs called ampullae of Lorenzini that can detect electrical signals as low as half a billionth of a volt. Hammerheads glide gently over the sea floor—like the shark in the video is doing—in search of the electrical pulses given off by buried stingrays. When it finds a ray, the shark pins it to the bottom with its head and eats the ray from the wings inward.
6 Barreleye Fish
By mid-childhood, most of us know what anglerfish look like. They’re the textbook deep-sea monster, most often used as an example of how different life in the deep sea is from life just about anywhere else in the ocean. But while they’re definitely high on the creep factor, perhaps even more bizarre is a little-known fish called Macropinna microstoma.
Also known as a barreleye fish, this sad-faced recluse lives between 600 and 800 meters (2,000–2,600 ft) below the surface. The species was first described in 1939, and although it was a strange enough fish to begin with, it wasn’t until we saw it in its natural habitat that we truly grasped how alien it was: The top of its head is a transparent dome, and its eyes can swivel like binoculars to look straight up through its own skull. None of the early illustrations of barreleyes showed that—the fragile dome was always destroyed when specimens were brought to the surface in nets.
Researchers at the Monterey Bay Aquarium Research Institute (MBARI) in California have managed to change just about everything we know about this species. After piloting an unmanned research vehicle to a depth of 600 meters in the Monterey Canyon, they stumbled across a hypnotic sight: a barreleye fish in its natural habitat. In the video, the green spheres are its upward-facing eyes. When it needs to, it can swing them down to look out the sockets in the front of its face.
The MBARI research team has also captured incredible footage of a female anglerfish with a brightly lit esca (the little fishing pole). They believe that it’s the first time anyone has ever filmed that particular species in its natural habitat.
5 Surfing Dolphins
Despite their affinity for group rape and infanticide, dolphins routinely fall on the adorable side of nature. It’s not exactly a surprise—cetaceans, which includes dolphins, are famously intelligent animals, and any creature with the intellectual capacity for boredom is likely to be involved in a fair amount of both violence and sunshine frolicking. For example, in 2010, an orca at SeaWorld Orlando dragged its trainer into the tank and drowned her. The chilling part is, experts believe that the orca knew exactly what it was doing—it wanted to kill her.
But in this video, we get the sunshine frolicking. Filmed with a quadcopter byfilmmakers Jennene and Dave Riggs, the video gives us a spectacular aerial view of a pod of dolphins lining up to surf waves off Esperance, Western Australia. Dolphins have been known to do this both on their own and with human surfers, and as far as anyone can tell, they just do it because it’s fun.
4 Flounder Camouflage
From sea dragons to stonefish, the sea is full of masters of camouflage. The ability to blend in with your surroundings is an important skill in a world where death can come from any direction at any time, and few fish have mastered it as effectively as the common flounder.
Like most other color-changing animals, flounder accomplish their disappearing trick through chromatophores, irregularly shaped cells that can contract or expand, thereby making specific colors or patterns more prevalent on the animal’s skin. The change happens slowly in some animals and more quickly in others, with flounder being one of the latter. In fact, they’re so adaptive to different environments that researchers were able to get a flounder to emulate a checkerboard pattern within seconds. And, as seen in the video above, they can even reproduce the shapes of individual stones and pebbles on the sea floor.
3 Sharks Swarming A Beach
This terrifying sight was captured at North Carolina’s Cape Lookout National Seashore in 2014. At first glance, it appears to be a swarm of birds picking up an easy meal from a school of fish trapped in the shallows. That is, until you see the first shark nearly beach itself on the sand.
Although the video doesn’t state what species the sharks are, experts think they were most likely blacktip sharks, which are common in the Atlantic Ocean, particularly off the coast of North Carolina. Although not overtly aggressive, blacktips are responsible for about 16 percent of Florida’s shark attacks on humans.
According to the above video’s uploader, Brian Recker, the feeding frenzy lasted for nearly five minutes, during which seagulls, pelicans, and sharks made short work of a school of bluefish. Recker estimated that there were more than 100 sharks there. It’s likely that that’s an exaggeration, but still—one shark is frightening, let alone dozens. At one point, the cameraman is close enough to get splashed by a shark’s thrashing tail. Recker made sure to clarify that the beach is usually perfectly safe for swimming.
2 Swimming Through The Silversides
“Devil’s Grotto” is a dark name for a beautiful place. Located in Grand Cayman, the intricate maze of stone tunnels and reefs is one of the most popular dive locations in the Caribbean. It’s not hard to see why—the place is an underwater wonderland of vibrant coral, glittering fish, and twisted geological formations that look like they’ve sprung straight from the primeval palette of time itself, all of it top-lit by a bluish haze of sunlight so soft you could die in it.
And once a year, millions of Atlantic silversides invade Devil’s Grotto and the surrounding waters in a seasonal migration that usually occurs in July or August. On its own, the Atlantic silverside is, arguably, one of the least interesting fish in the ocean. They grow about 13 centimeters (5 in) long, eat insects and algae, and resemble pale, ugly anchovies. But when they school, these little underdogs transform into living architecture that pulses and breathes with its own chaotic rhythm. Divers call it a “silver rush,” and the barrel-like structure that the silverside schools often take allows divers to get directly inside the mass of glittering fish, resulting in mesmerizing videos like the one above.
1 Flying Devil Rays
Devil rays belong to the Mobula genus and were nicknamed for the two points that grow on their heads. They’re not quite the same as manta rays, although they’re in the same family. But while “devil ray” is a cool nickname, it doesn’t hold a candle to their lesser-known moniker: flying rays.
And these babies soar. Researchers have no idea why they do it, but devil rays will regularly leap out of the water to heights of up to 2 meters (6.5 ft) before belly-flopping back into the sea. Of course, they aren’t technically flying—they just appear to because their wings will flap in the air, most likely to stabilize their flight. This quirky habit can often be seen in schools of devil rays, when dozens of them will breach the surface over and over in an acrobatic display straight out of Neptune’s weekend ballet rehearsal.
But the question remains: Why? Why waste the energy? There are several theories at large in the scientific community, though none have been proven. Since the flying rays hit the water with a full-frontal smack rather than a graceful dive, it’s been suggested that they’re using the concussive force of their reentry to drive schools of shrimp to the surface for easier feeding. The jumpers are usually located at the perimeter of the group, which might be another clue as to why, although nobody’s sure what that clue means yet. Then again, it’s always possible that they just like the way it feels. It certainly looks fun enough.
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