The fossil record hints at a trend of shallow origins diversifying into the depths for certain marine organisms. However, conflicting results arise from approaches based on genetics, some supporting an onshore-offshore evolutionary pattern while others propose the opposite.

Enter the world of scleractinian corals, the stony or hard corals, a perfect testing ground for studying biodiversity across massive depth gradients. These corals span a wide depth range, from the ocean’s surface to depths surpassing 6,000 meters. How these creatures spread and settle in different areas, influenced by changes in their physical traits, help us understand the complex ways they’ve evolved over time and in response to the deep sea Take Micrabaciidae, a family of scleractinian corals. They have a slender, porous skeleton covered entirely by tissue—a probable adjustment for survival in the deep sea, where crafting a larger, sturdier skeleton becomes challenging due to lower aragonite, a form of calcium carbonate needed to build shells and skeletons, levels.

Half of the scleractinian corals form vibrant shallow reefs, while the other half, independent of the photic zone, thrives in cold waters across diverse regions and depths. This diversity not only paints a vivid picture of the coral world but also holds keys to understanding the origins of deep-sea life and diversity.

A new study by Campoy et al asks four key hypotheses about evolution of scleractinian corals

1. Origin of these corals might trace back to the upper bathyal zone (200–1000 meters). The steep and varied nature of this zone creates distinct environmental conditions, potentially fostering diverse adaptations across depths and serving as a catalyst for biodiversity
2. Lineages where symbiosis or coloniality emerged saw heightened rates of colonization. If these traits indeed bolstered the corals’ ability to spread, their emergence should align with faster colonization rates.
3. A prolonged evolutionary trend favoring faster colonization toward shallower waters. This hypothesis assumes that the common ancestor of these corals lacked symbiotic relationships and lived solitarily, suggesting that symbiosis inherently links to the sunlit zones, with colonial species generally occupying shallower depths compared to solitary ones.
4. Evolutionary forces predominantly shaping species’ depth ranges occur more significantly in shallower waters. As depth increases, environmental variability and interactions among species decrease, potentially slowing down the evolutionary pace through deeper zones.

The intricate dance of evolution (too much?) reveals itself through deep-water origins, surviving multiple geological changes and even global anoxic events. Specifically, the results show that the order Scleractinia originated 415.8 million years ago somewhere between 229–2287 meters depth. The emergence of the Scleractinia order in the deep sea aligns with a pattern of evolution from offshore to onshore and not providing strong support for upper bathyal zone origination as in hypothesis one. However, various coral lineages spread and settled at varying rates across different depths. Moreover, the pace of colonization slows at greater depths, underscoring the vulnerability of these ecosystems to further and current human exploitation.

Campoy, Ana N., et al. “Deep-sea origin and depth colonization associated with phenotypic innovations in scleractinian corals.” Nature Communications 14.1 (2023): 7458.

The post From Depths Unknown: Deciphering the Origins of Deep-Sea Biodiversity first appeared on Deep Sea News.

Because my other post today is just a wee bit ranty, here a tranquil set of awe-inspiring videos for your consumption.  The ribbon eel is the only species in its genus, meanings it is pretty unique, in the larger family of Moray eels.  The ribbon eel, Rhinomuraena quaesita, is found among the lagoons and reefs throughout the Indo-Pacific oceans.  If you note the snout on these critters, you will see the flared nostrils.  This is usually the only part sticking out from burrows.  Apparently, the ribbon ells use these to attract small prey, clamping down on the unsuspecting food with their strong jaws and retreating into their burrows.  In addittion, all ribbon eels begin life as males and then ultimately become females.  This is called sequential hermaphroditism.

The post Ribbon Eel Video Roundup first appeared on Deep Sea News.

I firmly believe that good science must always be accompanied with good storytelling. Now more than ever, we must connect those around us to the work we are doing both intellectually (in a way they understand) and emotionally. What better way to do this than in a children’s story book?

One of my personal heroes and an extraordinary scientist whose work we have highlighted here and here, Dr. Danielle Dixson has just announced her first children’s book, “Sea Stories: A Butterflyfish’s Journey to Find Delicious Food.” With co-author and illustrator Caroline Cook, Dr. Dixson tells a story of Buddy the Butterflyfish and his search for food on the reef. This riveting tale parallels Danielle’s work across several local reefs in the Fijian islands looking at how fish can manage chemically noxious seaweeds on corals. And like any great story, this memorable book alludes to some pretty significant lessons for us all to take to heart regarding our roles in the health and balance of these delicate ecosystems.

For those of you with young ones, please consider supporting this wonderful series and the excellent work that Danielle is doing in science and science communication.

Get Your Sea Stories today!

The post Support Sea Stories 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.

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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.

Another year of science closes, giving us pause to review those new species of sharks described in the scientific literature, bringing the total number of known shark species to 512. Perhaps it’s a hollow victory to have so many different species known at a time when sharks populations worldwide are either in decline or in a complete population tailspin. But as taxonomists continue to kick ass and give names, our knowledge of shark evolution, biogeography, and ecology continue to get richer. Meet the new sharks of 2015:

Ginglymostoma unami, the Pacific Nurse Shark
This isn’t really the brand-spankin’ new species you might think, but it has been known for well over a century. The Nurse Shark (Ginglymostoma cirratum) had a disjunct distribution between the Caribbean and Gulf of Mexico and the eastern central Pacific oceans, meaning their range was divided into two separate populations. Like some nooks in the Ozarks, land barriers prevented gene flow, so the populations were both physically and genetically separated by a small spit of land called Central America. This team didn’t use genetic methods to test if the populations were distinct enough to be considered different species, but relied on a meristics, the process of compiling detailed measurements of the shark’s anatomy and comparing these values between the populations.  However, a 2012 paper on populations genetics of G. cirratum showed that the Pacific population was genetically quite unique, and divergent from any of the Atlantic populations. Since these two nurse shark populations had been separated by three million years, a few things can happen, like speciation. Indeed, their analysis showed that these two species are morphologically different enough to warrant giving the Pacific population its own scientific name. This name, G. unami, is an acronym of their alma mater, the Universidad Nacional Autonoma de Mexico.

Moral-Flores, L.F.D., E. Ramirez-Antonio, A. Angulo, and G. Perez-Ponce de Leon. 2015. Ginglymostoma unami sp. nov. (Chondrichthyes: Orectolobiformes: Ginglymostomatidae): una especie nueva de tiburón gata del Pacífico oriental tropical. Revista Mexicana de Biodiversidad 86 (2015) 48-58.

Scyliorhinus ugoi, Dark Speckled Catshark
Way down among Brazilians sharks once swam there in the millions, but overfishing took surely took a hefty toll, yet there are still new shark species to be found. Case in point: a new catshark that had long been swimming along most of the Brazilian coast but had been confused as other known species. Catsharks are a widespread, diverse, and somewhat confusing group of sharks. Differences in color, morphological changes between juveniles & adults, and sexual differences between males & females create difficulties in sorting out just how many species there are. Here, the authors use detailed meristic analysis to extract out a species that had been there all along, but the morphological features that delineate the species had not yet been defined.

SOARES, K.D.A. & GADIG, O.F.B. & GOMES, U.L. 2015. Scyliorhinus ugoi, a new species of catshark from Brazil (Chondrichthyes: Carcharhiniformes: Scyliorhinidae). Zootaxa, 3937 (2): 347-361.

Atelomycterus erdmanni, Spotted-belly Catshark

This sexy beast is one of the more colorful species of catsharks, and is one of several new species discovered from a larger taxonomic mess called the coral catsharks.  Using meristics, genetics, and biogeographical analyses, it turns out that the “coral catshark” represents several species, with this species as the newest. They don’t live in coral, so much as they crawl on and among coral reefs of Indonesia, using their pectoral and pelvic fins like tiny feet and walking like a more limber and agile salamander. Named after Mark Erdmann, a fish taxonomist who collected most of the known specimens, and was rewarded with this li’l shark bearing his name.

Fahmi & White, W.T.  2015. Atelomycterus erdmanni, a new species of catshark (Scyliorhinidae: Carcharhiniformes) from Indonesia. Journal of the Ocean Science Foundation 14: 14-27.

Bythaelurus tenuicephalus, Narrow-head Catshark
2015 also brought us two more catsharks, from the same genus, and both from the depths of the southwestern Indian Ocean. Hailing from the outer continental shelf of Mozambique and Tanzania comes the Narrow-headed catshark. The vast majority of sharks in recent years have been from the more remote pockets of Earth’s oceans, and in particular, from the deep oceans that have barely been explored. This species of Bythaelurus is a “dwarf”, a species that is sexually mature at a much smaller size than most other species in its genus.  The advantage of dwarfism might allow this species to breed at a younger age, thus increasing their overall lifetime reproductive output. Or it could be that being smaller simply means eating smaller prey that larger species of catsharks might miss. This sort of niche-partitioning may explain why there are so many different species of catsharks. The species name tenuicephalus means “narrow head”, a little less imaginative than some names, but descriptive nonetheless.

KASCHNER, C.J. & WEIGMANN, S. & THIEL, R. 2015. Bythaelurus tenuicephalus n. sp., a new deep-water catshark (Carcharhiniformes, Scyliorhinidae) from the western Indian Ocean. Zootaxa, 4013 (1): 120–138.

Bythaelurus naylori, Dusky Snout Catshark
Another year, another catshark on the list.  This species however, has quite an interesting story behind its capture.  Massive trawlers, towing huge nets and pulling up tons of fish aren’t new, but what is new is the trend for these huge vessels to move from depleted fishing grounds in the shallows, and into the relatively untapped fishery resources of the deep sea. In addition to the targeted commercial species that will earn them great sums of money when they return to port, these nets also catch and kill tons of other non-marketable species.  This is what ecologists call ‘by-catch’, but there is a sunny side to such needless destruction.  Commercial vessels are often the first to explore deep-sea zones, well ahead of research cruises that are difficult to fund and even more impossible to sustain over time. If you can get onto one of these factory trawlers, the bounty of the bycatch is yours, and what a paradise this is to shark researchers. Dave Ebert & Paul Clerkin of the Pacific Shark Research Center at Moss Landing Marine Lab got the invite to board one of these vessels as it sailed south from Mauritius, but with a small catch: they had to stay for the entire three month trawling season. If you haven’t ever had the displeasure of sailing the wild waves and howling winds where the Indian Ocean meets the Southern Ocean, then you wouldn’t know that it makes The Deadliest Catch look like a Honolulu harbor cruise. Already hardened by the seas of the Gulf of Alaska, Paul made three of these cruises, collecting more than a dozen new species of skates, rays, sharks, and chimeras that will be published in future years. The species name naylori honors Gavin Naylor of the College of Charleston who, through genetic analysis, is compiling a more complete evolutionary history of extant shark species.

EBERT, D.A. & CLERKIN, P.J. 2015. A new species of deep-sea catshark (Scyliorhinidae: Bythaelurus) from the southwestern Indian Ocean. Journal of the Ocean Science Foundation 15:53-63.

And lastly….
Etmopterus benchleyi, Ninja Lanternshark
If you haven’t already seen this sassy new deepsea shark that went viral late last year, check it out here, and here, and here. That makes six new sharks for 2015, but new species will be discovered and described in 2016, so check back next year.
VÁSQUEZ, V.E. & EBERT, D.A. & LONG, D.J. 2015. Etmopterus benchleyi n. sp., a new lanternshark (Squaliformes: Etmopteridae) from the central eastern Pacific Ocean: Journal of the Ocean Science Foundation; 17: 43-55.

The post Meet the New Sharks of 2015 first appeared on Deep Sea News.

In the last several years, the reefs have drawn swift open-ocean fish, like tuna and mackerel, that use the reefs as hunting grounds for smaller prey. Sea bass like to live inside the cars, while large flounder lie in the silt that settles on top of the cars, said Mr. Tinsman, the Delaware official.

States have experimented with other types of artificial reef materials, including abandoned automobiles, tanks, refrigerators, shopping carts and washing machines.

Subway cars in general, he said, are roomy enough to invite certain fish, too heavy to shift easily in storms and durable enough to avoid throwing off debris for decades. (via NY Times article)

Gothamist has some great photos of these subway car shipwrecks, but if you want an even more immersive experience then check out this video of a subway car scuba adventure:

The post TGIF: Subway Car Artificial Reefs! first appeared on Deep Sea News.

Sub-Neritic Gentrification

For November we will be doing some deep thinking about deep-sea mollusks in an attempt to understand the complex history and adaptations of these animals living in the depths of our oceans. Biodiversity of today’s marine snails can be traced to several different ecological and environmental phenomena, but in the Deep-Water Helmet Shell Galeodea keyteri, it is likely a case of adaptive radiation exploring new realms. The Helmet Shells (Cassidae) are a speciose group of large, shallow-water tropical and temperate marine snails that range among the intertidal coral rubble and sand flats to offshore muds, but as this evolutionarily successful group of gastropods continued to diversity into different niches, several species moved into deep-water to establish new ways of living. At these depths staying alive presents serious challenges with an extremely cold, low oxygen, nutrient-poor, and high-pressure environment, so some deep-water species trended to smaller, slow-growing physiologies like as a way to successfully conserve energy and resources. Since the dark depths lack sunlight needed for algae to grow, most species of deep-sea mollusks are either scavengers or predators, with little resources for vegetarians to survive. Like all Helmet Shells, Galeodea keyteri is a carnivore, specializing on starfish, brittle stars, and urchins. Catching their slow-moving prey with a muscular foot, glands in the proboscis secrete a fluid rich in acids that dissolve the echinoderm’s calcium-carbonate skeletons, while a radula drills into the weakened parts of the body to extract nutrients from their internal organs. A tough environment requires innovative strategies and hardy adaptations for a species to survive. Ain’t natural selection grand?

Molluscan Methuselah

While some species of deepwater mollusks are derived from shallow-water taxa that extended into and adapted within deep ocean ecosystems, other taxa of marine mollusks are taxonomic geezers with a much longer history. The Slit Snails (Pleuorotomariidae) are perhaps the oldest still-living lineage of marine snails, extending back in the fossil record more than 500 million years. Named because of its long slit at the aperture allowing for extension of their respiratory siphon, they were abundant in the shallow reefs throughout the world. Between the Late Cretaceous (ca. 90 million years ago) and the middle Eocene (ca. 40 million years ago) is when most modern lineages of shallow-water reef-living gastropods originated and diversified, and also the time when slit shells seem to disappear from that same fossil record. Among paleontologists and malacologists, the general hypothesis is that these modern taxa somehow out-competed the slit shells for food, or perhaps were more adapted to changing marine climates or fluctuating sea levels of the time, forcing the slit shells into progressively deeper and deeper water. This type of ecological displacement and bathymetric submergence has been seen in many other deep-sea groups, including corals, crinoids, brachiopods, and fishes. Today, slit shells are found in depths exceeding 3,000 meters, living the hi-life eating sponges in a cold, dark, lonely, nutrient-poor world.

Die-Hardest

As far as the origins of deep-sea gastropods go, we’ve visited two scenarios: new lineages of shallow-water snails radiating into deeper waters, and those formerly shallow-water taxa that have been out-competed in the shallows and forced into deeper, less productive habitats. But there’s a third group of deep-water snails that are so tough, so extreme that they can live in shallow and deep water. Here is the Checkered Hairsnail (Trichotropis cancellaria; Capulidae), the James Bond, the Bruce Willis, and the Rock all coiled up into one extreme snail that ranges from the intertidal zone to depths of nearly 2,000 ft. (600m). Is it true grit or it’s hard-boiled soul that make it impervious to the relentless cold, pressure, and darkness of the deep sea? Their broad range is more likely the result of two things: (1) a wide and variable physiology that can tolerate the extremes of shallow to deep; and (2) its broad diet that it can obtain at any depth. You see, the Checkered Hairsnail is a suspension-feeder, meaning it feeds on the decomposing bits of animal debris suspended in the water, which it traps by sticky mucous, and that kind of detritus is found in all habitats. However, it’s a sneaky critter. When the floating slurry of decomposition becomes scarce, they will parasitize tube worms by inserting their proboscis down the mouth of the worm and pumping out the contents of the worm’s stomach. Evolution: the weirder the better.

Slo-Mo Snail
Shallow-water gastropods live the good life. Warm water, a sunny sea rich in oxygen, and plenty of food provides them the metabolism to live fast, grow big, and die young, relatively speaking, of course. The flipside in the deep sea is a life of constant near-freezing cold, little available food, and water suffocatingly sparse in oxygen. This shell of the Catalina Turrid (Antiplanes catalinae, Pseudomelatomidae) who lives at depths of up to 4800 ft (1460 m), tells its story of life in this harsh realm. Growth lines, which indicate the increase and cessation of shell development, are seen as wide bands often far apart in curving spire of fast-growing shallow-water shells. In this species, the growth lines are close and compact, showing very slow growth and likely a long life. Their low metabolism provides little extra energy for their minimal growth and reproduction, so these snails probably take the developmental route of the tortoise over the hare. This shell tells another and more concerning story. Once only collected during deep-ocean trawls by research vessels, this species was prized by collectors as a rarity and an oddity. With commercial fisheries abandoning over-exploited fishing grounds along the shallower coasts, fishing has gone into the deep ocean to tap into those fragile resources. This specimen was taken as unintentional bycatch by a deep-water shrimp trawler, and though it wasn’t the target of the fisheries, the sparse populations of these slow-growing snails cannot sustain even the modest impact by commercial fisheries

Post-Docs Please Enquire

The curse of working with deep-sea gastropods is how few specimens are in museum collections, and what very little is known about them. That too is the siren’s call of opportunity in deep-sea malacological research. The Japanese Pagoda Shell (Columbarium pagoda, Turridae) has been known to science for close to 200 years, based on relatively few well-documented specimens in museums and private collections scattered throughout the world, yet virtually nothing is known about their ecology. Diet, trophic niche, age, growth rates, reproduction, population structure, predators, parasites, physiology, ecological associations, movements – none of that has been adequately documented. If all mysteries in the ocean were solved, there would be no jobs for future under-paid post-docs or over-worked assistant professors. Those with grant funding, a modicum of workaholism, and access to deep-sea technology could pioneer new directions into a richer ecological understanding of the deep ocean’s marine mollusks. That siren’s call can just as easily dash unfeasible projects on the rocks of financial destitution and lead to deep regret of one’s research program and entrée into a life of constant self-medication and personal validation. These mysteries await the bold, but favor the wise.

The post Malacology Monthly: Going Deep first appeared on Deep Sea News.

Superheroes?  Who gives a heck.  I was too busy reading marine biology text books than to waste my time with the imaginary – and usually blatantly contradictory – special powers of comic book superheroes.  In the real world, becoming invisible is an easy task for an octopus:
Maybe you are caught unaware.  No problem, just blend into whatever looks good, like a strand of red algae:
Maybe your cloak of invisibility is not enough to hide from a predator, what to do?  Get really angry, very large, and look tough enough to scare them off. Bluffing is 9/10 of survival (something I learned in that Turkish prison):
Becoming invisible (or looking really pissed off) requires three simple things: (1) you will need an excellent sense of vision to relay your local environment to your brain to modify your (2) layers of stacked pigment cells called melanocytes to expand or contract, varying the color & shading of your body to re-create the color of your surroundings, and (3) relaying the physical aspect of your environment to tiny muscle fibers that instantly change to texture of your skin to mimic your substrate. Boom, gone (but still in plain sight).
 One layer of specialized cells, iridiophores, glam up the octopus with iridescent blues & greens.  These aren’t pigments, but cells that contain specialized components which take in ambient light and refract only the blue spectrum.  What lame-ass superhero can even bend light like that?  None. Moreover, this little Blue-Ringed Octopus has some nasty venom, so the pulsing blue rings warn a potential predators, but may also be irresistable to little kids poking around in tide pools.  Oops.

Having the superpower to flash colors & textures and immediately change shape aren’t just for fighting super-villains, but in this fast-paced world of evolution, cephalopods have come up with some excellent ways of just staying alive by a quick color change and expansion of muscles. Our friend the Mimic Octopus uses what’s called a ‘startle behavior’ in an attempt to scare off a potential predator (in this case, the underwater cinematographer):
The Mimic Octopus brings up its game by using the ability to quickly change into other sea animals. Here it looks like the feathery striped fronds of the vemomous Lionfish’s fins, and the black & white banding pattern of a highly-venomous sea snake, the Banded Sea Krait:

Octopus, squid, and cuttlefish all share highly muscularized tentacles, basically specially modified divisions of their boneless foot.  Octopus have suckers with an impressive ability to grip, and an amazing level of fine dexterity to solve problems like this:
Squid tentacles may have a combination of suckers alone, or suckers with piercing hooks or sharp saw-toothed edges to grip and maim their prey, as seen in these Humboldt squid: Octopus move with jets of water squirted through their siphon, and the intensity and direction of the blasts accelerates and steers the animal as smoothly as a hoverboard.
Squid aren’t that different from a personal spacecraft in those sci-fi comics, and these have a certain similarity to George Jetson‘s space car (but without George). With their siphon blasting jets of water and the fins along the side of the head undulating in waves that steer them, they can hover in place and instantaneously dart in any direction, and use their tentacles for streamlining, signaling, or attacking:
Now take this these concepts of color change, tentacles, and a personal hover-suit, and turn your little cephalopod body into some crazy disco predator. Using a neural network that coordinates the melanocytes and iridiophores into pulsating waves of light visually confuse – or possible mesmerize – prey enough to give you a split second to shoot your incredibly elastic predatory tentacles right in their face and pull them into your sharp killer beak. This is why the marine world is better than any comic book.
Ok, so maybe you want to be seen.  You’re a hot, sexy, ripe squid with gametes a-plenty and it’s the season for love.  But in the deep, dark ocean it’s hard to find the right mate. No problem, some squid have specialized bioluminescent cells in your skin where a tiny internal chemical reaction emits light energy in little glowing spots.  Your species may have a special pattern that identifies the right mates for you.  Not interested in love?  Those same light spots may attract prey that you can feast on until the moment is right for that special copulatory embrace:

So it’s been a while since the squid love-fest, and now your life is taken up with caring for the kids.  Sure, most squid just mate then dump a fertilized egg capsule on the ocean bottom and let those li’l squidlets hatch on their own, but not with Gontaus.  She may not be the world’s best mom, but unlike other squid, she carries her egg mass around to protect her little brood until the time they hatch.  When they do, she pulsates the eggs gently kicking them out into the big dark world below, like shaking sand off a beach blanket.  Once they are out, they are on their own and she has nothing more to do with them: Again, not the greatest mom, but better than most:

Next up, cephalopods have the highest cute factor of any invertebrate, more than flatworms, more than gastropods, and even more than those fancy-pants Peacock Spiders. I enter into evidence this contest between two little squid tucking themselves in for the night.  Looking like they were designed by a Japanese toymaker, the Pyjama Squid (Sepioloidea lineolata) and the Tropical Bobtail Squid (Sepiadarium kochi) will burow into your hearts:
Don’t need any fancy bed because the sea floor is soft enough? Well then dig right in with a few blasts of water.  No turn-down service required:

Most of all cephalopods just want to be left alone.  When color changing, jetting away, burrowing into the sand, or impersonating more dangerous sea creature doesn’t work, there’s always just losing your shit and kicking ass:

The post Cephalopods: Masters of W.T.F? – Enough GIFs to Kill a Kraken first appeared on Deep Sea News.

Among the many revelations of recent studies of Gulf of Mexico deep-sea coral beds is that squat lobsters appear to be the lazy ninjas of the deep-sea. They sit waiting in coral beds practicing ju-jitsu while hapless squid drift by unawares. The crabs were presumed to be suspension feeders because of their posture on corals, but recent observations indicate they will attack fish and squid, even ROVs.

The post Dancing Squat Lobsters of the Deep first appeared on Deep Sea News.

1) Cockles got feet, and they know how to use ’em. This isn’t a tongue, or some other fleshy pink appendage, but rather a foot, and a long, distensible, and flexible one at that. When in the sand, this foot extends deep into the sediment, and as it contracts, it pulls the shell down into the sand beyond the eyes of its predators. When you dine on cockles, this is what you eat.

2) Trippy aquatic castanets? Ghost shell from a Japanese horror movie? Nope, this is a scallop doing what scallops do for much of their life – trying to get the heck away from a predator. Unlike cockles that hide beneath the sand, the muscular adductor that snaps the shell shut creates a jet of water that moves them in short, jerky blasts through the water. While their escape plan isn’t all that great, it may just be good enough to get out of the path of slow-moving starfish, their most feared predators.

3) You can almost hear the thumping oonce oonce oonce rave beats where the disco clam lives. It’s not really a clam at all, but a very flamboyant bivalve called the Electric Flame Scallop. Their light show pulsates within the fleshy mantle, making small mesmerizing blasts of light. Unlike most respectable sea creatures, they don’t generate bioluminescence, instead they reflect ambient light through a thin layer of silica microspherules embedded in their flesh, making the light appear as electrical currents in that outer layer of skin. The hot-pink feather boa of tentacles may give them additional glam-rock cred, but they also contain distasteful sulfur compounds, so the blinking lights may give potential predators a fair warning for the subsequent mouthful of regret.

4) Octopus are (literally) cold-blooded killers, and they’ve got a whole toolkit of ways to subdue different kinds of prey. With clams, they grasp the shell with their tentacles, and using a sharp tooth-studded tongue, drill a small hole through the shell and inject a paralytic venom. The drugged clam relaxes its grip and they octopus can easily pry the shell open. With the former tenant now lunch and just a fading memory, the octopus takes over the clam’s home and uses the thick shell for protection from its own predators, keeping one eye open for danger.

5) Squee Alert! Bears and clams rarely meet, but when they do the results can be sickeningly adorable. Grizzly bears along the Pacific Coast often forage for marine invertebrates at low tide, and have even been seen pawing through the sand for clams. This young grizzly is learning the art of clam digging, yet hasn’t perfected the technique, and now has a huge cockle clamped to one of its claws. You’re Welcome!

The post Five Mind-Blowing Bivalve GIFs That Will Blow Your Mind – Your Blown Mind Won’t Believe #6! first appeared on Deep Sea News.