The above photo is of Apolemia lanosa a type of siphonophore belonging to phylum Cnidaria that also includes corals and jellies.  It’s basically the ocean’s way of celebrating Christmas all year long.  Like many other Cnidarians, siphonophores bud new individuals—exact clones themselves.  In a manner similar to Christmas elves although this is not proven by science. In the case of some Cnidarians, the clones never leave home so family never has to travel for the holidays.  

In some Cnidarians, clones in the colony will specialize but among siphonophores the specialization is unrivaled. Clones will specialize for feeding, defense, locomotion or reproduction. The feeding clones catch food by tentacles equipped with cells that shoot out poisonous harpoons stinging and stunning their prey.  In the most popular of all siphonophores, the Portuguese man o’ war, with a large gas filled buoyant bladder adapted for catching the wind and sailing.  Interestingly, all the clones are attached via a single digestive and circulatory system.  Research is still needed on which clones are adapted for drinking eggnog, singing carols, and wrapping gifts.

 The species of Apolemiidae may be record holders for the longest animals on earth. Fragments of specimens of this family with a length of over 30 meters have been reported from the French Mediterranean coast in the bay of Villefranche-sur-Mer. In most physonect siphonophores clones are arranged along a central stem, it itself the founding clone developed from a single egg.  At the front end, is a group of clones that are propulsion clones. Basically, Santa’s reindeer if Dasher, Dancer, Prancer, Vixen were all budded from and identical to Santa.  In the larger and remaining region of a physonect siphonophore, one can find the clones for engaging in the spirit of Christmas, eating and…  New clones are formed in special growth regions of the siphonophore.  As new clones are formed the old clones get pushed down the line. But Apolemia species are special.  In addition to other clones Apolemia can also add new feeding clones along the entire length of the stem. This fact might be the reason why members of this particular family of siphonophores can grow to such tremendous length.

The post The Ocean’s Gelantinous Christmas Tinsel first appeared on Deep Sea News.

The goal was to create a tree where the top represented the ocean’s surface and the base representing the abyssal floor. With a series of white, blue, and black ribbon and silver and blue miniature bulb ornaments, we created the effect of attenuated light as you move deeper. We wanted to make sure to include both a remotely operated vehicle on a lighted tether as well as lighted bathysphere. The tree also included a giant squid attacking a shark and whale fall complete with crabs and eels. We also made some tiny experimental wood falls to resemble the real ones we now have deployed all over the Gulf of Mexico.

You can print all of these decorations yourself. The complete collection can be found in my Thingiverse collection and include:

• The research vessel on top is the ICE – the icebreaker by vandragon_de (with the addition of little printed A-frame for the aft deck.
• The basic and blocky (or to sound like a sophisticated maker low-poly) remote operated vehicle was designed by us.
• Giant Squid by TheGreenFilament
• Shark! Sliced to Print by MacGyver
• Starfish model by Empiricus
• The Voyage of the Bathysphere by themindseye
• LOW POLY CRAB by RaffoSan (for whale fall)
• Eel by Benc (for whale fall)
• Whale by YahooJAPAN (whale for whale fall)
• Giant Deep-sea Isopod by the one and only Andrew_Thaler. (The model is actually based on a real specimen in our lab.)
• Puffer Fish (of awesomeness) by Dinoman (garland)
• A simple log by Montravont
• Vampire Squid by sinryan
• Hammerhead Shark by pmoews

The post 3-D Printing the Ulitmate Deep-Sea Christmas Tree first appeared on Deep Sea News.

https://youtu.be/FuMxVu9F7XU?t=10s

Check out this incredible video of jellyfishing (aka ‘jellyballing’). The first part of the video, with the brown-colored jellyfish, is from the US state of Georgia, where jellyfishing is one of the state’s largest fisheries. The second part of the video, with the blue jellyfish, is from the Gulf of California, Mexico. And the third video, with the man and the net…well I’m not actually sure where that’s from. Possibly South America.

In all three cases the species being harvested is supposedly the ‘cannonball jellyfish’ Stomolophus meleagris. However, recent work done scientist Dr. Liza Gómez Daglio is shaking this idea up a bit: using DNA, she discovered there are at least six undescribed species of cannonball jelly, possibly more (paper).

We don’t actually know the species boundaries for all these different cannonball jellies, so it’s hard to say if some species are being fished more than others. Though the blue ones vs brown ones are clearly very different.

Regardless of species or color, nearly all of the jellyfish caught in the US are shipped overseas to Asian markets, where people enjoy jellyfish in a variety of different dishes. Personally, I find jellyfish to be a bit like eating chicken cartilage crossed with rubber bands. While it may be an acquired taste, clearly many people have it: a recent paper reports that “Japan has imported 5400–10000 tons of jellyfish products per year, valued at about 25.5 million US dollars, annually from the Philippines, Vietnam, Thailand, Malaysia, Indonesia, Singapore and Myanmar” (paper).

Thousands of tons of jellyfish is a lot by any measure. But how many tons of jelly are caught in the Americas is harder to say. Scientists have no idea what impact, if any, jellyfishing has on jelly populations here in the US, particularly for undescribed cannonball species. In China, fisheries experts bump up the jelly population by ‘seeding’ wild jelly stocks with hundreds of millions of baby jellies each year. That’s right: China actually adds hundreds of millions of jellyfish to their coastal waters annually. Good jelly harvesting and culturing practices may help make their jellyfishery sustainable over the long term, while feeding demand for these crunchy, rubber band-esq invertebrates. With more information on the US cannonball species, perhaps we could develop similar conservation measures to help preserve and protect our local species, while also supporting local fisherman.

Regardless of how we protect our local species, I doubt jellyfish will become a popular snack here in the US anytime soon. While I’d love to catch jellyfish by the boatload, when it comes to eating jellyfish, my personal favorite is still the Swedish kind.

The post Jellyfish fishing: A multi-million dollar industry first appeared on Deep Sea News.

For more updates on my research, follow along at jellybiologist.com, or on twitter @RebeccaRHelm

As a scientist, I love jellyfish, and I suffer for it. Up until a few years ago, I had no way of knowing exactly where or when the jellyfish I study would appear. So I traveled to Washington and France and Florida looking for them, and more often than not, came up empty handed. The most frustrating part of all this travel was that I had all the species I needed right at home, but couldn’t use them. That’s because jellyfish, like butterflies, are the last stage in a complicated life cycle. Jellyfish have a stage that’s analogous to a caterpillar, termed a ‘polyp’, which lives happily in the lab. So imagine studying butterflies, and having all the caterpillar you need, expect none of them will metamorphose. No matter how hard you try to convince them, they just sit there eating leaves, and so you travel all around the world to find and study the actual butterflies. That is the exact position researchers and aquarists have been in with jellyfish.

This is why I’m so excited to share with you a paper I just published in PLOS ONE on a simple method for triggering metamorphosis in a huge variety of jellyfish species. Now, rather than traveling halfway around the globe, scientists can add a couple drops of a special compound to their polyp tank, and have jellyfish to study in under a week! I hope this work will be helpful to many different kinds of jelly-lovers, form biologists to aquarists and beyond.

This research started out of frustration. I’d been traveling for over two years looking for the best species to study, and was consistently coming up short. I wanted to better understand the process of metamorphosis, called ‘strobilation’, but I needed to find a species that would easily strobilate in captivity. No luck. And so one day, rather than going out to look for jellies,  I decided it was time to spend a couple months indoors, to test out a hair-brained idea that was all together different.

Throughout the decades, a handful of scientist have recorded that this-or-that chemical, when added to water with this-or-that polyps species, will trigger strobilation. Most of these papers stretch back to the 70’s and earlier, and most have been largely forgotten. But I decided it was time to revisit those old studies, and test out different chemicals. The experiments were messy and quirky–I had a bunch of chemicals, jars, and polyps all soaking in different substances for different lengths of time–but I remember the exact moment when I got my first breakthrough.

I carried a small dish of polyps, which had been soaking in a type of chemical called an ‘indole’, to the microscope. I was working alone in the lab, and I was feeling pretty discouraged. It’d been two weeks of stirring up different chemical solutions, doling them out in precise proportions, and checking every single day for signs that the little polyps had begun metamorphosis. Nothing. But when I looked down at the polyps soaking in indoles…well, I think my lab notebook can express it better than I can (there was, um…some language):

Each polyp had formed a small ring below the tentacles. This ring was the first sign of metamorphosis. Each ring would eventually grow to be a tiny jellyfish (the pictures at the top of this post are the same animals I saw that day!) This species is the Pacific sea nettle, but the same compound also worked for species from the Atlantic and Indian oceans. Almost every species I tried would dutifully metamorphose into a tiny jellyfish.

Not only did this open up a whole new research avenue for me, it has become the foundation for my career. Now we can have tiny jellyfish of almost any species in under a week. Even box jellies!

But here’s a result that’s got me head scratching: one type of polyp, from a crown jellyfish, didn’t strobilate with the indoles. I tried all sorts of different combinations of conditions, nothing worked. But there are a couple really cool things about crown jellies that may explain why they didn’t respond. First, the polyp lives in a small tube, unlike any other species. So it’s possible the compound didn’t work because the polyp is mostly tucked away behind a barrier. But the second cool thing about this species is that it’s a very distant cousin of most of the species that I studied. So it is possible that over evolutionary time it evolved a slightly different biochemistry, which makes it insensitive to indoles. Similar to the way catnip gets cats high, but doesn’t have the same impact on people. Indoles works well on many related species of jellies, but not so well on a distant relative.

I’m now working on figuring out the reason why indoles works so well for some species. What genes might this compound help turn on and off? By studying metamorphosis in jellyfish, I hope to better understand how metamorphosis evolved over long time scales. For example, are there genetic similarities of metamorphosis between frogs, butterflies, and jellies?

Those results are still pending. For now, I’m enjoying all the new jellies we have growing in the lab. And I hope these results can be helpful to all those seeking to learn more about jellyfish in this coming new year!

Paper:

Rebecca R. Helm & Casey W. Dunn (2017). Indoles induce metamorphosis in a broad diversity of jellyfish, but not in a crown jelly (Coronatae). PLOS ONE 12(12): e0188601. doi:10.1371/journal.pone.0188601

The post New Research Reveals How to Easily Grow Jellyfish In Captivity first appeared on Deep Sea News.

Giant squid are the sea’s best monsters, tentacles down. For evidence we need look no further than the logo of this very website. But did you know that our beloved Architeuthis descends from a venerable line of sea monsters—that Archy’s ancestors, in fact, may have been the first animals ever to merit the name “monster”?

The phrase “prehistoric sea monster” might summon to mind an ichthyosaur or megalodon, but these are johnny-come-latelies to the underwater scene. Megalodon showed up a mere 23 million years ago. Ichthyosaurs evolved closer to 250 million years ago, which may seem pretty old (okay, it is) until you consider the age of the first cephalopod: 450 million years.

I’ll admit that initially cephalopods were no monsters. Snail-like, they lived inside shells that measured a few centimeters at most. But these shells contained a remarkable evolutionary innovation: sealed-off chambers that could be drained of fluid and filled with buoyant gas.

This buoyancy freed cephalopods from the constraints of their heavy shells, allowing them to reach stupendous sizes. No matter how big the shell grew, its weight was automatically offset by more gas-filled chambers.

Endoceras giganteum, for example, grew up to 3.5 meters, longer than a basketball hoop is tall. It was the biggest animal the world had yet seen. I feel confident calling this 450-million-year-old beast one of the planet’s first monsters.

But how did we get from Endoceras to Architeuthis? Is one a direct ancestor of the other, or are they distant cousins n-times-removed? And what became of that fantastic shell?

We need a family tree for Endoceras, Architeuthis, and everything in between—in other words, a cephalopod phylogeny. For over a century, scientists have been working to reconstruct such a phylogeny with evidence from fossils, embryos, DNA and more. I made an attempt to synthesize the most recent work into a single drawing, with lots of advice from paleontologists and the helping hand of an artist who polished my messy sketchwork (and put in those friendly eyes).

Endoceras was one of the Orthocerida, which you can find down in the Ordovician, in the lower right. Today’s giant squid take pride of place—with their smaller siblings—top and center. As for the rest…

From Cambrian through Silurian times, cephalopods all wore their shells on the outside of their bodies, just like every other self-respecting mollusk. The nautiloids continued that decorous habit to the present day. Another externally-shelled group, the ammonoids, explored every bizarre baroque extreme of shell coiling and ornamentation before getting mass-extincted alongside the dinosaurs.

What remains are the coleoids—the only group of cephalopods in which evolution sheathed the shell, burying hard structure inside a soft body.

At first, this internal shell was still massive and still full of buoyant chambers, as in the early coleoid Hematites. But over time natural selection (carried out by hungry fish, for the most part) favored smaller, simpler shells.

Now, cuttlefish and ram’s horn squid are the only modern coleoids to retain the hard calcium and buoyant chambers of their ancestors. The internal shells of octopuses have evolved into mere vestiges.

And squid? Well, the shell remnant of a squid has no chambers and no calcium. But it runs the full length of the body, from head to fin-tip, and it offers support to the powerful muscles that carry these modern monsters through the sea. Though unarmored, Architeuthis is most likely faster and far more agile than Endoceras could ever have dreamed of being.

So which one would you rather meet in a dark alley?

The post How the Squid Lost Its Shell first appeared on Deep Sea News.

On July 20th, 1963, three scientists sat on a research ship 200 miles south of Woods Hole, MA, waiting for something remarkable. They were nearly 4000m above the seafloor, and using a sounder (similar to sonar), they could ‘see’ a line of creatures resting in the deep. By this time, biologists were beginning to unravel the mystery of this ‘false bottom’–a layer in the ocean that looks the the sea floor on the sounder but isn’t–which covered much of the ocean. This false bottom rises in up at night and sinks down during the day. This rising and falling is in fact caused by the largest migration of animal on Earth–everything from fish, shrimp and jellyfish, moving hundreds of meters in unison up and down each day. But how and why these animals rose in fell in the ocean wasn’t clear. As the scientists watched their instruments, the light began to fade. Not from the setting sun, but from something else.

The scientists were trying to answer a question that could be answered literally no other way. Some experts suggested that this massive migration was due to each animal’s own biological rhythm; the same rhythm that causes you to feel jet lag after a long trip. But others thought that the sun itself was driving this massive shift from shallow to deep and back again: as the sun set, animals saw the dimming light and rose to the surface. As the sun rose, they sank again into the deep. How could the scientists test between these two different hypotheses? They can’t exactly alter the sunrise…

Luckily, Earth’s view of the sun is altered once a year thanks to a cosmic twist–when the moon blocks it from view. A solar eclipse on land can be an eerie phenomenon. Nighttime crickets and frogs begin to sing, birds fall silent, even bees return to their hives. But until recently, what happened in the ocean depths was a mystery.

Back on the research ship in 1963, the moon moved into its place in front of the sun, daylight rapidly faded, and the scientists solved the migration mystery: the deep layer of animals began to rise. Bioluminescent creatures started to shine, and nocturnal creatures started a frantic upward thrust. As the world grew darker, they swam upward nearly 80 meters. But this frantic migration didn’t last long. As the moon receded and the sun revealed itself, the massive animal layer did an about-face, scrambling back into the safety of the darkness. One can only imagine the frenzy as millions upon millions of creatures clambered towards the surface and then, just as quickly, rushed back to the deep.

On the boat the scientists could only observe this massive movement with sounder. But it was enough to answer their question. Thanks to the solar eclipse, we now know that animals hiding in the deep are governed in part by the external ebb and flow of light from the sun.

Ancient humans considered eclipses ominous signs. Now, modern humans adopt a more spectator role in this celestial occurrence. There’s even a citizen scientist initiative to understand how creatures on land responds during the upcoming eclipse. But for millions of creatures living in the open ocean, a solar eclipse, at least for a short time, may really spell calamity.

Work cited

RH Backus, RC Clark, AS Wing. (1965) Behaviour of certain marine organisms during the solar eclipse of July 20, 1963. Nature. 4975. pp 989-991

The post What happens in the sea during a solar eclipse? first appeared on Deep Sea News.

Imagine you are a Janthina snail, living on the surface of the open ocean, clinging to the edge of a raft. Miles of emptiness all around. In the day, rays of sunlight spear through the water, coming to a point so far below you can no longer see where they end. At night everything is black, you can almost feel the emptiness like a pressure, tingling on your skin. You cling to your raft as if your life depended on it, and it does. You don’t know how to swim.

You created the life raft you cling to—a collection of bubbles that keep you afloat. Your thin purple shell is heavy, and your body stout, if you let go you will will sink: first through the warm surface waters, and then the ocean will grow rapidly cold, light will fade and the pressure grow, it will take over two hours for your corps to hit the seafloor with a soft thud and a puff of muddy water. And so you hold on, and you build.

Your snail body is especially equipped to handle this strange world your ancestors somehow found themselves floating into. When you can, and when there’s need, you dip your head and upper body into the air. You curl your slimy underbelly into a ball, trapping a bubble and wrapping it in a layer of thick mucous. Carefully, you uncurl and stick this new bubble to your raft. Your snail slime hardens to a stiff rubbery texture, not easily popped. Sometimes your raft bumps into your prey— blue button jellies or Portuguese man-of-war— but you can’t steer or choose your direction out here in the open ocean, so much of the time, you simply wait. But you did not always live this way.

When you were young you lived below the surface, in the gentle embrace of the sea. You were free to move and hunt as you pleased. Your body was different, tender and round with a miniscule cup-shaped shell that covered your frame, and two small ‘wings’ that you used to swim. But it didn’t last. First, your vision went dim. Then you eyes began to break down, and blindness overtook you. Next, your ability to sense direction faltered, up and down became indistinguishable. No one knows quite how you made it to the surface. Some say you made a parachute of mucous that you used to sail slowly upwards. In the most poetic telling, you built yourself a minute bouquet of bubbles, clustered together at the end of a long string, like a handful of balloons. Blind and disoriented, you floated up into the unknown.

And then you hit something. The first boundary you’d ever felt—the soft rolling surface of the sea. Here you would complete your transformation into a young violet snail. Floating, unable to steer, you would have no need for eyes, no need for a sense of direction. This is where you would spend the rest of your life: at the mercy of the elements, suspended above the abyss.

Reading about the violet snail on that dark winter night, its life felt so precarious, so sad. But my friend Steve Haddock proposed another way of looking at things: one completely flipped around, literally. What if Janthina isn’t hanging over the abyss at all? There’s this scene in Pirates of the Caribbean where the ship flips upside down, and instead of sailing on the ocean, the ship sails on the sky. Perhaps to Janthina, the world is just like this. Instead of clinging to a raft, one mistake away from sinking, Janthina has a different view. Maybe to this snail, so perfectly adapted to life on the water’s surface, it’s not hanging upside down over the abyss, but instead resting right-side up on the top of the sky

Bibliography
Dan Laursen (1953) The Genus Ianthina: A Monograph.

Carol M. Lalli, Ronald W. Gilmer (1989). Pelagic Snails: The Biology of Holoplanktonic Gastropod Mollusks.

The post The harrowing life of the violet snail first appeared on Deep Sea News.

The Bakken Sea was unlike any ecosystem that exists today. Now, instead of the dry plains of North Dakota, imagine floating on the surface of this sea about 380 million years ago. The evening air is moist and musty, the sinking sun is dipping low, the sunset a wash of muted colors gleaming off crumpled black waves. Algae near the surface collect the last rays of sunlight, combining light with water and carbon dioxide to make organic matter. A strange collection of prehistoric animals feed on these algae (and each other) here at the sea’s surface, but to truly understand the Bakken, we must go underneath.

Standing underwater, on the Bakken seabed, there is no visible life. There is almost no oxygen in the water around you, transforming the seabed into a “dead zone.” You are at the bottom of a large basin—a bowl in the ocean floor nearly 400 miles wide . As the struggles of life play out in the waters above, the old, sick and defeated sink to their graves on the seabed. But without oxygen, they do not fully decompose, and nothing ventures this deep to scavenge upon their carcasses. Instead, billions upon billions of bodies–mostly algae but some larger creatures, too–slowly amass on the seafloor, forming a layer of organic matter known as the ‘lower Bakken.’

Fast forward through geologic time several million of years into the future: the sea level rapidly drops, and the basin becomes shallow with quick-moving currents. Sediment tumbles in from the surrounding mountain ranges. A layer of sandy, porous rock that covers and buries the layer of bodies. This sandy layer is knows as the ‘middle Bakken.’ Fast forward one more time: the sea rises again, and the first stage repeats, blanketing the seabed once more in dead remains, this is the ‘upper Bakken.’

These three layers—the lower, middle and upper Bakken—are then covered by sand and rock, compressed, and heated in a perfect combination of conditions that geologists refer to as an ‘Oil Kitchen.’ Slowly, this kitchen converts the Bakken carcasses into a diverse collection of gases and complex molecules called hydrocarbons–the fossils that make our fuel [2].

The lower and upper Bakken layers are sludgy and dense, difficult to drill into. But as the remains in these layers liquify, their old resting places crack open under the extreme weight and pressure . The bodies of these ancient dead sea creatures, long immobilized in their graves, now move again: the liquids of the lower and upper Bakken layers seep into the spongy middle Bakken layer. It is from this middle layer that, millions of years later, that they will be exhumed.

To harvest fossil fuels from the Bakken reserve, we drill wells thousands of feet down into the middle layer, and then extend them an additional two miles horizontally, maximizing the amount of oil we can harvest (Continental Resources, PDF). A high pressure mix of sand and water, called ‘proppant,’ is pumped in, fracturing the rock and opening small pockets of oil, which ooze through the cracks and are captured in the well.

Before the beginning of this month, this ‘crude oil’ was pumped into trucks or trains, destined for refineries. But as of June 1st, it instead enters the Dakota Access Pipeline–traversing multiple states, eventually destined for national or international refineries. At refineries, the ancient ocean remains of the Bakken Sea will be processed into the oil in your car, gas in your tank, and plastic lid on your morning coffee cup. Transporting oil via pipeline will potentially reduce the risks and costs associated with overland transport. But the 1,172  miles of pipeline raise a suite of new humanitarian and environmental concerns, including possible spills at important water sources like Lake Oahe, and destruction of sacred sites associated with the Standing Rock Indian Reservation. Protesters tried to stop the pipe’s construction, or have it move it to a new location. Just today, a federal judge ruled that proper environmental procedures were not followed before the pipeline was approved. But for now at least, this long stretch of pipe will be the primary way these remains march across the plains.

Back in in Williston, North Dakota, business is booming; this small community is undergoing an oil-fueled renaissance. After one last look around at the dry grassy expanse, you get back in your car, turn the key–the gas ignites, the combustion moves the oily gears, and drive away.

Additional information

[1] Depositional Facies And Petrophysical Analysis Of The Bakken Formation, Parshall Field, Mountrail County, North Dakota (http://geology.mines.edu/Bakken/NETL_DOE/DOE-Student_theses/Andrea_Simenson_THESIS.pdf)

[2] http://www.glossary.oilfield.slb.com/Terms/o/oil_kitchen.aspx

The post The Ancient Ocean of the Dakota Access Pipeline first appeared on Deep Sea News.

As a result of anthropogenic climate change, sea level has risen approximate 7 inches in the past 100 years. With the combination of melting land ice and expansion of warmer seas, scientists conservatively predict a 1-4 foot rise by the year 2100. Effectively, sea level rise poses widespread and continuing threats to the economy and environment of coastal regions.

To reinforce the urgency of this situation, New York based artist Eve Mosher, started to walk the line. Literally. Using a baseball field chalk marker, Mosher laid a 70 mile white line of chalk in 2007 across Manhattan and Brooklyn. The HighWaterLine as it was called, demarcated the areas that would be severely impacted by increased mega floods if climate change continued. The power of this public installment truly hit home ironically in 2012 when the flooding brought on by Hurricane Sandy surpassed the proverbial “chalk line.”

“Walking the line with the participants and hearing of their stories after the event provides concrete evidence of the power of transformation of HighWaterLine…I hope that in every instance, HighWaterLine is just the beginning of these communities working together to build resilience and transform their cities.” says Mosher.

Since the first exhibition of the HighWaterLine, the project has debuted in five different cities from Bristol to Miami, the most climate vulnerable U.S. city. Along with the art piece, the project is also accompanied by interactive workshops to get the community more involved in the climate conversation and provide tools to create a culture of change. Currently, the group is working on a Action Guide to mentor others in bringing the HighWaterLine project to groups around the world.

The post The Writing on the Sea-Wall: High Water Line first appeared on Deep Sea News.

If I asked you to picture a predator, weighing over 2 tonnes¹ and capable of travelling the distance of a marathon every day², what would it look like? Would you imagine sleek shapes, immense power or maybe terrifying teeth? What if it could also dive >840m deep³, swarm in huge numbers⁴ and produce over 300 million offspring⁵? Such a creature sounds like the stuff of nightmares, spawning thousands of B movies where people fear to tread water… introducing the ocean sunfish!

Oceanic oddballs

These crazy-looking creatures have hit the headlines again and for good reason… just look at it. The bizarre shape, the enormous size, the permanently surprised expression; sunfish are simply swimming clickbait! Firstly in 2015 Boston Man broke the internet with his idea of catching a ‘baby whale’ (*spoiler, it’s a sunfish) and now a hilarious rant about the “biggest joke played on earth” has gone viral, again with sunfish as the butt (or should that be swimming head?) of the joke. But what is it about these oceanic oddballs that inspires such outbursts?

Well, even someone who studies sunfish for a living like me has to admit they are pretty weird, both to look at and in their habits, but that is precisely why I find them so fascinating. So what do we really know about this strange species? Alongside the jokes, Scout Burns’ comic rant made some pretty fishy claims about sunfish and the scientists who study them, so I feel it’s time for someone to stand up for the funny-looking fish and bite back.

Dishes to fishes and the meaning of life

One of my favourite suggestions from Scout’s blog is that sunfish are “big dumb idiot[s]” made when “God must have accidentally dropped [one] while washing dishes day and shrugged his shoulders” because they have “no purpose… every foot… wasted space”.. Well sometimes the truth is stranger than fiction; the fishes first evolved around 500 million years ago⁶ and despite their somewhat prehistoric appearance, the ocean sunfishes actually represent the new kids on the block (evolutionary speaking)! They appeared ‘only’ 50 million years ago, descended from pufferfish that left for a life in the open ocean⁷. Their strange shape actually represents cutting-edge evolutionary design, honed by selective pressures over millions of year to a life wandering the world’s oceans. As to their purpose, well this is a bigger question… the meaning of life has been debated for centuries from ancient philosophers to Monty Python (of course the answer is: 42). But roughly speaking, their “purpose” is the same as that of all life… simply to exist: to feed, grow, breathe, reproduce and die. Of course, having an interest in biology, we want to know a few more details than that! Which is why scientists (myself included) are trying to unravel the ecology of the sunfish a little further…

Why swim when you could fly?

Scout suggests “scientists even debate how [sunfish] move. They have little control… some say they must just push water out of their mouths for direction…They could use their back fin, except… it doesn’t f****** grow. It just continually folds in on itself.” The image of a giant sunfish blowing water like a kid blows bubbles is a great one! But sadly this simply isn’t the case, we know how they move and in quite a lot of detail. Rather than swim with a strong tail fin (like most sharks and tuna species), the ocean sunfish flaps its dorsal and anal fins like a penguins flippers⁸ to efficiently (if a little ungainly), fly through the water. The funny stumpy tail (or clavus) actually has a vital role to steer the fish, like a ship’s rudder (and for the record it grows like any other body part).

Scout quite rightly mentions that sunfish don’t have swim bladders; however it is not true that “that every fish has [one] to make sure it doesn’t just sink”. In fact, although it might sound strange, many fish don’t have swim bladders, including great white sharks, manta rays and white marlin. There are other ways to provide lift without the issues of containing air internally (which can cause problems with rapid changes in depth). Most fish without swim bladders, including sunfish, have large deposits of fatty lipids in their livers that provide buoyancy, so no swim bladder, no problem⁹.

Unfortunately it’s also not the case that sunfish “get stuck on top of the water… because without the whole swim bladder thing… the ocean pushes over the [fish]”. This idea sounds super funny as sunfish are often seen bobbing around at the surface, but unfortunately is untrue. Sunfish don’t actually need a swim bladder to remain upright (it’s not a life jacket); they are perfectly capable of swimming upright both at the surface and at depth. They “bask” at the sea surface¹⁰, which is a clever behaviour to increase their heat exchange, to communicate with birds for cleaning services and perhaps simply just to rest, before diving back into the depths.

Under pressure…

Of course being a huge fish, there is a certain amount of Hollywood pressure to be a tremendous toothy terror and Scout’s article sounded distinctly disappointed that despite being “so huge” sunfish are not even “decent predators”. Unless you are a prey item of course! The biological definition of a predator is ‘an animal that naturally preys on others’ and so sunfish are oceanic predators. But of course this particular predator poses little threat to people, unless you are unfortunate enough to stand under a breaching sunfish, in which case you may find yourself transformed into a pancake-ified version of a human being. But as a biologist, this doesn’t seem like the best method for classifying predators (although it might win you a Darwin Award).

Back to sunfish as predators, (an area a lot of researchers are working on), Scout says “They mostly only eat jellyfish because [it has] a possibility of drifting into their mouths I guess. Everything they do eat has almost zero nutritional value and because it’s so stupidly fucking big, it has to eat a ton of the almost no nutritional value stuff to stay alive. Dumb.” Well, that’s the funny thing really –they really can survive on a crazy diet! Small sunfish (<1 m), eat a wider range of things than their larger cousins, with 40% of their diet made up of seafloor creatures including crustaceans, molluscs and even some fish species¹¹. When they come across gelatinous prey (siphonophores, pyrosomes, jellyfish etc.) the sunfish are surprisingly fussy and are careful to only eat the most calorific parts (no dieting here!) which means gonads… yum. Anything that requires more energy to find or digest than it provides -like jellyfish bell tissue- is rejected. By remaining fussy eaters within their ecological niche (where unsurprisingly, there is less competition), sunfish are able to survive where few others can, something biologists (myself included) are still trying to understand and explain.

Moving on from thinking of sunfish prey to sunfish as prey, and it’s hard to imagine this giant floating head being vulnerable to attack. However, sunfish start life in the plankton as tiny eggs <1 mm⁵. This puts them on the menu for almost every creature in the sea! As they grow, the number of predators able to cope with such an item decreases, but they have been found inside sharks¹² (not a pretty sight) and there is plenty of evidence of attacks by orca¹³ and sealions (although these might aggressive play behaviours, like a cat tormenting a mouse). The main threat to ocean sunfish, the super predator that kills 100,000’s each year is… you’ve guessed it: us. There are markets for sunfish meat across the Far East (Taiwan and Japan in particular¹⁴) and they are captured as unwanted bycatch by fisheries globally¹⁵. It is these enormous catch figures that have led to the ocean sunfish being classified as Vulnerable to extinction by the IUCN Red List.

However the future for this funny fish is becoming brighter; as more people become aware of the oceans weird and wonderful creatures, from funny rants and viral videos, more pressure is placed on governing bodies to reduce bycatch, combat climate change and alter unsustainable exploitation of the seas. Perhaps ranting and raving about strange species can be helpful for conservation, simply by raising awareness and creating a catalyst for change.

If you would like to read more fish facts or learn about the latest sunfish research please check out my twitter page @SunfishResearch or visit my blog sunfishresearch@wordpress.com

References

¹ Roach J (2003) World’s heaviest bony fish discovered? National Geographic. Available via http://news.nationalgeographic. com/news/2003/05/0513_030513_sunfish.html

² Nakamura, I., Goto, Y., & Sato, K. (2015) Ocean sunfish rewarm at the surface after deep excursions to forage for siphonophores. Journal of Animal Ecology, 84, 590-603.

³ Phillips, N.D., Harrod, C., Gates, A.R., Thys, T.M., & Houghton, J.D.R. (2015) Seeking the sun in deep, dark places: Mesopelagic sightings of ocean sunfishes (Molidae). Journal of Fish Biology, 87, 1118-1126.

⁴ Houghton JDR, Doyle TK, Davenport J, Hays GC (2006a) The ocean sunfish Mola mola: insights into distribution, abundance and behaviour in the Irish and Celtic Seas. J Mar Biol Assoc UK 86:1237–1243. doi:10.1017/ S002531540601424x

⁵ Gudger EW (1936) From atom to colossus. Nat Hist 38:26–30

⁶ Conway Morris S and Caron JB (2014) A primitive fish from the Cambrian of North America, Nature 512, 419–422

⁷ http://oceansunfish.org/evolution.php

⁸ Watanabe Y, Sato K (2008) Functional dorsoventral symmetry in relation to lift-based swimming in the ocean sunfish Mola mola. PLoS ONE 3:e3446. doi:10.1371/journal. pone.0003446

⁹ Yancey PH, Lawrence-Berrey R, Douglas MD (1989) Adaptations in mesopelagic fishes. Mar Biol 103:453–459

¹⁰ Cartamil DP, Lowe CG (2004) Diel movement patterns of ocean sunfish Mola mola off southern California. Mar Ecol Prog Ser 266:245–253

¹¹ Syväranta, J., Harrod, C., Kubicek, L., Cappanera, V. & Houghton, J.D.R. (2012) Stable isotopes challenge the perception of ocean sunfish Mola mola as obligate jellyfish predators. Journal of Fish Biology, 80, 225-31.

¹² Fergusson IK, Compagno LJ, Marks MA (2000) Predation by white sharks Carcharodon carcharias (Chondrichthyes: Lamnidae) upon chelonians, with new records from the Mediterranean Sea and a first record of the ocean sunfish Mola mola (Osteichthyes: Molidae) as stomach contents. Environ Biol Fish 58:447–453

¹³ Gladstone W (1988) Killer whale feeding observed underwater. J Mammal 69:629–630

¹⁴ Sagara K, Ozawa T (2002) Landing statistics of molids in four prefectures of Japan (in Japanese with English abstract). Mem Fac Fish Kagoshima Univ 51:27–33

¹⁵ Pope, E.C., Hays, G.C., Thys, T.M., Doyle, T.K., Sims, D.W., Queiroz, N., Hobson, V.J., Kubicek, L. & Houghton, J.D.R. (2010) The biology and ecology of the ocean sunfish Mola mola: A review of current knowledge and future research perspectives. Reviews in Fish Biology and Fisheries, 20, 471-487.

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