The post Friday Video: Top 10 deep-sea animals from MBARI 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.

And luckily for us, Roxanne posts all of her adventures as they happen on her Istagram and Twitter feeds. Even better—Roxanne is currently on an expedition to explore the deep-sea Gulf of California with Nautilus Live, which is live broadcasting all of its dives for the world to watch. So you too can follow Roxanne and the octonaut crew on their real-life mission of discovery. As they say on the show: Octonauts, let’s do this!

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The #octonauts are back at it! Join us with @nautiluslive as we explore new vent and seep sites off the coast of Mexico. Dives will start in a few days!

A post shared by Roxanne Beinart (@rbeinart) on Oct 19, 2017 at 5:10am PDT

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Arrived at the ship and getting settled into the snazzy top bunk

A post shared by Roxanne Beinart (@rbeinart) on Oct 19, 2017 at 5:06pm PDT

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The #octonauts are steaming to station with @nautiluslive

A post shared by Roxanne Beinart (@rbeinart) on Oct 20, 2017 at 4:57pm PDT

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Working hard, processing samples with @nautiluslive

A post shared by Roxanne Beinart (@rbeinart) on Oct 22, 2017 at 2:30pm PDT

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#octonauts #roxbscience

A post shared by Roxanne Beinart (@rbeinart) on Oct 8, 2016 at 2:37pm PDT

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Look closely at the boxing glove. The #octonauts are psyched about this gup! #roxbscience

A post shared by Roxanne Beinart (@rbeinart) on Oct 8, 2016 at 10:38am PDT

The post When real-life marine biologist and mom goes to sea, she takes the octonauts with her first appeared on Deep Sea News.

With lyrics like

Cries of trout in your sleep
That you lure there with krill
There’s a taste in your mouth
of shrimp cocktail swilled

I know you will enjoy!

h/t Laura Brueckner

The post Koi Division 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.

Gloop from gaby bastyra on Vimeo.

The post GLOOP. first appeared on Deep Sea News.

The shell-less gastropods of the sea are collectively known as “sea slugs”. A well-known subgroup of these mollusks, the nudibranchs, are among the most colorful and captivating creatures in the ocean. Nudibranch (noo-də-bránk) means ‘naked-gill’, referring to their external filamentous respiratory organs; one of the physical characters that distinguishes them from other sea slugs. “Nudis”, as they are affectionately called, are also a quite successful clan. Over 2000 are species are known to inhabit marine environments around the planet, from the extreme depths of the seafloor to the littoral pools of the intertidal zone.

The waters of Cabrillo National Monument host at least 25 different species of these soft bodied jewels, a few of which may be observed during a good low tide. With the right timing and a keen eye, one can pick out the small but unmistakable Hopkins’ rose nudibranch (Okenia rosacea). They are one of the more common nudibranchs found here and perhaps the least inconspicuous of all the tidepool organisms at the park. Though small–only 2-3 centimeters long–it’s hard to miss their bright pink, frilly papillae swaying in the water.

The rose nudibranch was first described in 1905 by Frank Mace McFarland, a marine biologist from Stanford University and one of the founders of Hopkins Marine Station in Pacific Grove, California. McFarland, well known for his contributions to malacology (the study of mollusks), originally named the rosey-colored slug ‘Hopkinsia rosacea’ after his friend and patron of the marine lab, Timothy Hopkins.

Rose nudibranchs are carnivorous. They utilize their sensory organs, known as rhinophores, to locate their sole food source: the pink encrusting bryozoan, Integripelta bilabiata. They then extract the bryozoan’s soft tissue with specialized teeth. Like many nudibranchs, Okenia rosacea steals the toxins and calcareous spicules of their prey and place them into their feathery appendages for protection. In addition to nourishment and protective compounds, these nudibranchs garner their stunning color from their bryozoan food. The tissues of the bryozoans contain hopkinsiaxanthin, the compound responsible for the slug’’s intense pink hue; and a carotenoid that was unknown to science before its discovery in the tissues of these species.

Historically, the range of these nudis extends from Northern Baja California, Mexico up to the lower Oregon coast. But, until recently, they were rarely noted north of San Francisco. Over the last few years, however, Hopkins’ rose have been seen in surprisingly high numbers in parts of Northern California and have even been observed spawning in the coastal waters of Southern Oregon, a locality in their range that was previously only known from only one specimen. Researchers believe this shift may be due to a warm water anomaly occurring in the North Pacific in 2014 and find it indicative of warming climatic conditions in general.

Like other nudibranchs, Okenia rosacea is a simultaneous hermaphrodite. Equipped with both male and female reproductive organs, this species can mate with any other mature individual of the same species. The mated slugs will deposit their pink, ribbon-like spiral egg masses on rocks and other tide pool substrates. In the act of spawning, they deposit eggs from the outside working inward in a counterclockwise motion, thus creating a clockwise spiral. From the eggs hatch tiny planktonic larvae, which develop and eventually settle on the substrate to grow to adulthood.

The more you look into it, the more there is to learn about these bright, beautiful, and fascinating mollusks. The same can be said of just about any species. Our National Parks hold multitudes of life forms, each with myriad complexities and adaptations to discover.

The next time you are exploring the rocky intertidal of the California (or Oregon!) coast, keep an eye out for the truly splendid Hopkins’ rose.

Sources and Reference:

Bertsch H. “Life history of the intertidal Californian nudibranch Hopkinsia rosacea MacFarland, 1905”. Western Society of Malacologists, Annual Report, 1989 21:19-20.

Emerson, W. K., Morris, Robert H., Donald P. Abbott, and Eugene C. Haderlie. “Intertidal invertebrates of California” Stanford University Press, Stanford, CA. 1980 98,326

Goddard, Jeffrey H. R. Treneman, N., et.al , “Nudibranch Range Shifts Associated with the 2014 Warm Anomaly in the Northeast Pacific”, Bulletin, Southern California Academy of Sciences 115(1). 2016 :15-40

Strain H. H. “Hopkinsiaxanthin, a xanthophyll of the sea slug Hopkinsia rosacea”. Biological Bulletin97(1) 1949 :206-209.

The post That Which is Bright and Splendid 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.

It isn’t the first time DSN gets it’s underwater rave on, whether we are showing you the fluorescent corals of coral reefs, Red Sea underwater disco, or fluo raving diving on the Great Barrier Reef, we’ve always been keen to show you how to have a great time underwater and look stylish (or at least bright) while doing so. A returning theme besides how awesome it looks, is why? Why would there be an entire world of dazzling colours underwater that us puny humans can only see by using specials tools? While I don’t pretend to know the answers, I might offer a few suggestions that could make you look at it in a different light…either that or confuse you even more while showing pictures of pretty glowing fish.

As a short recap, biofluorescence is not the same as bioluminescence. In the latter, fish produce their own light, the former (which this blog is about) reflects colours from an external light source at a different wavelength. You can find the technical details here. While diving, we can only observe biofluorescence using a few aids: a blue dive torch to stimulate fluorescence and a yellow filter in front of the mask to block the excess blue light and only see the reflected colours. Originally the blue torches used were UV-lights, but increasingly we are finding that normal, high intensity blue light actually works better. It also has the added benefit that it doesn’t make you go blind if you stare at it for too long.

So there we are, blue light in hand, yellow filter on, ready to marvel at all things fluo. The question remains why? Looking at what happens on land might give a few clues, because biofluorescence is not limited to the ocean. Birds, scorpions, butterflies, flowers, etc. all show biofluorescence. It has been suggested to play a role in attracting pollinators, mates, or even detecting light levels. One of the few functions that has been proven, is that it is used as a sexual signal in parrots.

Now that we’ve ended up at sex, it’s time to get back in the ocean.

• The beautiful fairy wrasses seem to use biofluorescence in a similar way as parrots. Males of the Red-eyed wrasse (Cirrhilabrus solorensis) show stronger aggression to other males that are fluorescent than to those who are not. So potentially fluorescence could be a way to see potential sexual competitors.
• A second suggestion is that small fish might use it as a secret way of signalling to each other. Red light does not travel far underwater, which would allow fish of the same species that are close (such as potential mates) to see the signals, but predators that swim by at a further distance would not see the reflected light.
• Predators could use biofluorescence to their benefit as well. Recently frogfish with fluorescent lures have been documented. Their orange fluo lures are the same colour as biofluorescent free-swimming worm found nearby. So these frogfish might be using fluorescence to attract prey.

Of course, all these explanations depend on whether or not fish can actually see fluorescence, which is still an important point of discussion. The fact that many species that are fluorescent also possess yellow filters in their eyes similar to what we use for diving hints at the fact that they might. But simultaneously, the low light levels found in the ocean might be too weak to stimulate the reaction. So alternatively, marine biofluorescence could just be a quirky side-effect of evolution that serves no real purpose. Even if that would be the case, we can still marvel at just how beautiful the hidden quirks of the ocean can be.

Want more from Maarten ? Check him out online!

Instagram: crittersresearch

Blog: crittersresearch.com

Twitter: DeBrauwerM

His website: https://crittersresearch.com/

References:

De Brauwer, M., & Hobbs, J. P. A. (2016). Stars and stripes: biofluorescent lures in the striated frogfish indicate role in aggressive mimicry. Coral Reefs, 35(4).

Gerlach, T., Sprenger, D., & Michiels, N. K. (2014). Fairy wrasses perceive and respond to their deep red fluorescent coloration. Proc. R. Soc. B, 281(1787).

Heinermann, P. H. (1983). Yellow intraocular filters in fishes. Exp. Biol., 43(2).

Michiels, N. K., Anthes, N., Hart, N. S., Herler, J., Meixner, A. J., Schleifenbaum, F., Schulte, G., Siebeck U. E., Sprenger, D. & Wucherer, M. F. (2008). Red fluorescence in reef fish: a novel signalling mechanism? BMC ecology, 8(1).

The post Reef raving revisited: 4 good reasons for fish to glow in the dark first appeared on Deep Sea News.

I published my first book.

It’s a children’s sticker book all about the intertidal squishies that I love so much! Each page has a description of one of 12 critters and explorers of all ages can commemorate finding each one with a fabulous sticker. With the help of some amazing Park Service Volunteers, we are excited to share our love and passion for the Rocky Intertidal Zone with the masses.

You’ll have to come visit to get one. See you soon and happy tidepooling!

The post Tentacles, Tube Feet, and Other Sticky Things. first appeared on Deep Sea News.