A four-leaf clover represents just one kind of rareness. One might find a 4-leaf clover just about anywhere. Four-leaf clovers are not just restricted to Ireland. Four-leaf clovers are rare because at any given locality they occur in very minuscule numbers.

The idea of whether rareness imparts values has tormented philosophers, including Nietzsche. “Whatever can be common always has little value. In the end it must be as it is and always has been: great things remain for the great, abysses for the profound, nuances and shudders for the refined, and, in brief, all that is rare for the rare.” But of course, Nietzsche does not define rare. What does “all that is rare for the rare even mean?” Freakin’ Nietzsche.

We all feel we know what rare means. But contrast the case of four-leaf clovers with platinum. Platinum is special for me. For my 10th wedding anniversary, I had a custom wedding ring made of platinum for my wife. This platinum band was to replace one from our youth when I had more limited income and could afford a metal less “precious” and less “rare.” Yet, platinum represents another kind rarity, occurring in great abundance but only at a few locations. Locally abundant but geographically restricted.

In a classic 1981 paper, Dr. Deborah Rabinowitz, a professor at the University of Michigan, laid out the seven forms of rarity. What makes something rare depends on three characteristics; geographic range, habitat specificity, and local population size. First, is a species found globally or only at a single location? Two, is species seen at any given site in low numbers? Third, is the species only found in a specific type of habitat?

As Rabinowitz notes in elegant writing., “If each of these attributes is dichotomized, a 2 x 2 x 2 or eight-celled block emerges. Although creating the hazard of false reification – that is, converting an idea into an object – such a simple scheme can aid in focusing our thoughts, and this is my intention. The patina – a gloss or incrustation conferred by age – of monolithic rarity may have hindered our understanding of an exceedingly heterogeneous assemblage of organisms. Since the products of rarity are diverse, the causes of rarity and the genetic and population consequences of rarity are undoubtedly equally multiple.”

But obviously, 2x2x2 does not equal 7. One state is lost, a species found everywhere, in high numbers, and several different kinds of habitats. This species isn’t rare at all! You can think of the seven forms of rarity as three singe type cases (geographically limited/small numbers/habitat specialist), the three double type cases (geographically limited and small numbers/geographically limited and habitat specialist/small numbers and habitat specialist), and the last triple case (geographically limited and small numbers and habitat specialist).

The most uncommon form of rarity is a species found all over but in limited numbers at a single location. One such species is the exceptionally beautiful deep-sea snail Oocorys sulcata found in the eastern and western corridors fo the Atlantic and reaching will into the Indian Ocean and the western Pacific. Oocorys sulcata also show incredible depth tolerance found all the way from the shelf at 150 meters down to the deepest abyss over 5000 meters. Yet, despite this fantastic distribution, it is rarely found. A famous sampling effort off of New England did not capture a single individual in 41 samples. Another 24 samples later as part of later effort only yielded a single specimen. Indeed, based on some very rough calculations, you would probably only find about 15 every square kilometer or roughly 45 Manhattan city blocks.

Hydrothermal vents possess mollusks that are both unique and fascinating. A snail first described in 2003, the unusual snail Chrysomallon squamiferum, maybe the most exciting find thus far at a hydrothermal vent. I admit my bias here, as most of my interest lies with studying deep-sea snails. Nonetheless, the discovery of “gold-footed” snails a the Kairei vent field in the Indian Ocean is fascinating.

At this point, I should state that the foot of the snail is mineralized with pyrite and greigite. Many of you might note the misnomer here, as pyrite is only ‘Fool’s Gold,’ but in deciding on a temporary ordinary name Fool’s Gold-Footed Snail seemed a bit lengthy. I hope all will forgive the intentional misnomer for the sake of creative writing. Although other names due include the big-hearted iron snail (it also possesses an abnormally large heart for its size). And of course the scaly foot snail. So maybe the big-hearted, iron gold, scaly foot snail.

The scales, or sclerites, that cover the entire length of the snail’s foot can be up to 8mm long. The presence of mineralized scales is remarkable in itself, but the existence of iron sulfide as skeletal material is unknown from any other animal. The purity of sulfides, among other lines of evidence, suggest that the building of the scales is controlled by the gastropod itself. The sclerites are thought to have evolved recently and homologous to the operculum. It is believed they may serve as a defense against cone shells also occurring at the vent.

Chrysomallon squamiferum is rare, not only for the oddity of its features amongst the animal kingdom but because the snail is known from only three hydrothermal vents in the Indian Ocean. While abundant at any of these vents it is geographically restricted, like platinum. The scaly foot is actually a “double rare” case both geographically restricted and a habitat specialist. Given this potential habitat of only a few square meters, some of which endangered by deep mining interests, led a new paper by Dr. Sigwart and colleagues establishing Chrysomallon squamiferum as endangered on the IUCN RedList. This listing places the big-hearted, iron gold, scaly foot snail with 25 species all either bony fish, cartilaginous fish, or cephalopods all assessed to be either endangered or critically endangered.

Helen Macdonald writes in H is for Hawk “The rarer they get, the fewer meanings animals can have. Eventually rarity is all they are made of. The condor is an icon of extinction. There’s little else to it now but being the last of its kind. And in this lies the diminution of the world. How can you love something, how can you fight to protect it, if all it means is loss?”

I am hoping for future where Chrysomallon squamiferum I remember this elegant mollusk for the rarity of beauty, adaptation, and morphological marvel not the rarity of its existence.

Sigwart, J. D., Chen, C., Thomas, E. A., Allcock, A. L., Böhm, M., & Seddon, M. (2019). Red Listing can protect deep-sea biodiversity. Nature Ecology & Evolution, 1.

Rex, M.A., Stuart, C.T., Etter, R.J., & McClain, C.R. (2010). Biogeography of the deep-sea gastropod Oocorys sulcata Fischer 1884. Journal of Conchology, 40, 287.

Rabinowitz, Deborah. (1986). Seven forms of rarity and their frequency in the flora of the British Isles. Conservation Biology: The Science of Scarcity and Diversity 

Rabinowitz, Deborah. (1981) Seven forms of rarity. Biological Aspects of Rare Plant Conservation

The post The Beauty of Rarity first appeared on Deep Sea News.

I am not sure when this obsession with both small and large things began. One of the earliest photographs of me is in a giant rocking chair. With a big smile on my face, I am dwarfed by the colossal piece of furniture. Sadly, in researching this post I discovered this rocking chair is not the largest. That title is bestowed to a towering rocking chair, a 56.5 feet tall behemoth in Casey, Illinois, not only the world’s largest rocking chair but also the largest chair in all of America. I will of course need to visit, and photograph, myself next to the massive chair. Another photograph to add to my photo collection of myself with oversized objects. The world’s largest Adirondack chair and me…got it. Largest chest of drawers…done. Largest frying pan…visited. Giant 6-foot tall cheese grater…photographed and almost bought. I could go on and on.

I never realized I could get paid for my obsession. I did not at some point in high school realize or declare I wanted a vocation focused on extreme sizes. Nor was such a trajectory flagged as a possibility on those mandated vocational tests. I got flagged for being perfect for cake decorating. No joke. Nothing about decorating tiny or giant cakes. Of course, who would even think you could make a career out of a passion for size, except maybe Guinness World Records? No, I came by it all by accident.

As an undergraduate, I applied for a summer program to conduct research with a biologist. Knowing at the time I wanted to be a marine biologist, I applied to do summer research counting fish on the coral reefs of St. Croix. An unshockingly, popular choice among undergraduates, I did not get the position. My second and third choices were the only other ocean-based projects in the program. When the scientist involved with my second choice project called to invite me to work with him that summer, I didn’t even remember what the project was. I wasn’t really concerned with the specifics of the other projects because how could I not be selected for my first choice, St. Croix, dream project. Opposed to the beautiful tropical beaches of the Caribbean, my destiny would be to work in a windowless lab all summer in Boston. The project didn’t exceedingly interest me at the time as I wanted to be a field scientist and microscopy in the lab sounded…well dull. But working in an air-conditioned lab in the big city sounded better than living with my parents in rural Arkansas working in the intense Southern heat sweating in a factory. So off to Boston I went. Within a few hours of the first day, I fell in love with the project. So much so I asked that scientist, a preeminent deep-sea biologist and expert on the body size of marine invertebrates, if I could pursue a doctorate with him.

In the biological world, size is more than a novelty. How an organism relates to the world around it is determined by its size, and understanding what influences size is key to understanding the diversity of life itself.  That summer I measured the size of 100’s of tiny snails and when I returned to pursue my Ph.D. I measured thousands more. In total I measured 14,278 deep-sea snails. The largest no bigger than Abraham Lincoln’s head on the face of the penny. The smallest the size of his nose. Those snails I measured were collected from off the coast of New England from depths of over 600 feet to well over 18,000 feet, from the shallows of the New England continental shelf to the abyssal plains.

Why would anyone measure close to 15,000 snails? In the late 1800’s Henry Nottidge Mosely wrote: “Some animals appear to be dwarfed by deep- sea conditions.” By the 1970s, Hjalmar Thiel of Universität Hamburg observed that the deep sea is a “small organism habitat.” Increased depth typically translates into less food in the oceans with the deep-sea being a very food poor environment. As you might expect this has profound effects on the body size of deep-sea animals. Thiel’s seminal 1975 work demonstrated that with increased depth, smaller organisms became more dominant. At depths greater than 4 kilometers on the vast abyssal plains where food is extremely limited, you find some of the most diminutive sizes. In a particularly striking example of this, my doctoral advisor Michael Rex and I calculated those nearly 15,000 deep-sea snails I measured could fit completely inside a single Busycon carica, a fist-sized New England knobbed whelk found along the coast. But by measuring all those snails, Mike and I were able to document exactly how size in these snails changes over a 3.5 mile increase in depth. That study was the first of its kind and remains the largest number of deep-sea animals ever individually measured.

But to say that all creatures of the deep are miniaturized overlooks the complexity of size evolution in the deep sea. Some taxa actually become giants. The Giant Isopod, a roly-poly the size of very large men’s shoe, and sea-spiders the size of dinner plates, quickly dispel the Lilliputian view of the deep sea. Although all those deep-sea snails are smaller than their shallow-water relatives, shockingly Mike and I also found that they actually increase in size with greater depth and presumed lower food availability. To further confound the situation, other scientists have reported the exact opposite pattern in other types of snails, whose size decreases with depth. The same appeared to be true in other taxa, such as crustaceans. How can the deep-sea be both a habitat of dwarfs and giants?

To answer that, I turned from the Earth’s largest habitat to one of its smallest—islands. On islands both giants and dwarfs exist. The diminished kiwi and the enormous Moa of New Zealand, the colossal Komodo dragon on the island of Komodo, the extinct pygmy elephants on the islands of the Mediterranean, the ant-sized frog of the Seychelles, the giant hissing cockroach of Madagascar and the giant tortoise of the Galapagos represent just a few of the multitudes of size extremes on islands. In 1964, J. Bristol Foster of the University of East Africa demonstrated that large mammals became miniaturized over time on islands. Conversely, small mammals tended toward gigantism. This occurs with such frequency that scientists refer to it as “Foster’s rule” or the “Island rule.” Big animals getting small and small animals getting large.

My colleagues and I discovered a similar pattern in 2006 between shallow and deep seas. As shallow-water gastropods evolved into deep-sea dwellers, small species became larger and large species became smaller. Interestingly, size did not shift in a parallel manner. Larger taxa became disproportionately smaller sized—that is, both converged on a size somewhat smaller than medium. I’ve since observed this pattern in radically different taxa, such as bivalves, sharks, and cephalopods.

The fact that islands and the deep sea have so little in common represents a wonderful opportunity that allows elimination of several hypotheses. Of course, what the deep sea lacks is food. The absence of sunlight precludes plants.   Thus, for the majority of organisms living there, the food chain starts with plankton, dead organisms and other organic debris descending from the ocean’s surface. Less than five per cent of the total food available drifts to the sea floor, leading to an extremely food-limited environment. On islands, less food is available because the small land areas support fewer plants at the base of the food chain.

In either case, island and deep-sea animals need to be efficient and creative in their acquisition of food. In both habitats, there may not be enough total food to support populations of giants only. Unable to travel long distances to search for food or to store large fat reserves to fast through periods of food scarcity, smaller organisms are also at a disadvantage. If these contrasting evolutionary pressures were equal, size would be driven to an intermediate. However, the selection against larger sizes is greater, leading toward an evolutionary convergence that is slightly smaller than the intermediate size. Thus, differential responses to food reduction by different- sized organisms may resolve the outstanding paradox of divergent size patterns in the deep. In the interests of reaching this ‘golden medium’, some species become giant while others miniaturized.

In that summer of 1996, as a clueless undergraduate, I started my scientific adventure that fueled my obsession with size. Two decades later, I still am excited by the body size of animals. Much of my research, and the students who work with me, is dedicated to understanding how the expansive variety of sizes on Earth from bacteria to blue whales emerged. Did I mention the great selfie I took recently with a giant whale vertebra the size of coffee table?

The post Craig With Big Things (and Small Things) 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.

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.

The Tongue that Bites

Take this shell for example, so smooth it’s hard to tell if it was even in focus when photographed, is that of the Flamingo Tongue snail (Cyphoma gibbosum, Ovulidae). With satin pastel hues of pink and orange, the shell is worthy of a Miami Art Deco speakeasy, but the mantle that shrouds the shell adds a flair of early 1960’s cubist psychedelia. Most are barely

longer than an inch in length as adults, but size doesn’t matter since what they eat are the tiny, succulent coral-like polyps that make up the colonies within a sea fan. In the warm, shallow Caribbean Sea, a Flamingo Tongue Snail will graze on a sea fan, scraping and plucking out polyps, leaving a stark, lifeless trail behind. In areas where mollusk-eating fishes have been eliminated, the absence of their natural predators causes the snail population to explode, wreaking long-term and widespread damage to the slow-growing sea fans and the habitats they create.

Oyster Shooter

Who doesn’t love oysters? Ok, except vegetarians, and sure, those with shellfish allergies, but slurping down a raw oyster with a dab of Tabasco sauce and a squeeze of lime followedby an ice-cold lager is a marine biologist’s equivalent to a dose of Ativan. This water-worn little shell, less than two inches long, also loves oysters, but eats them in an entirely different way. The Japanese Oyster Drill (Ocenebra inornata, Muricidae) is far too small to eat an entire oyster, and too weak to pry open the shell, so it tries an entirely different method, one that you would expect in some freaky David Cronenberg film. The radula that in most species of snails are used as a rasp to scrape food off a

substrate, say algae off a rock or bits of meat off a dead fish. In this species, the radula is developed into an abrasive augur-like structure that can literally drill through the shell of other mollusks, and in particular, the sedentary oyster. Secretion of acidic enzymes through the proboscis containing the drill softens up the shell to make drilling quicker. Once the shell is perforated, the snail will then suck out the oyster’s fluids and soft tissues. Even more interesting, the evolution of a drill-like radula has been achieved independently in several different unrelated

lineages of predatory snails. But too many oyster drills can wreak havoc in an oyster bed, and this species in particular has been accidentally introduced into ecosystems far outside eastern Asia, proving them to be a serious invasive pest in regional shellfish industries.

Neritic Nosferatu
If you thought that a marine snail with an auger-like set of teeth drilling into an oyster to

suck out its juices was weird, I’m going to up the ante. As you’ve read in various postings about marine gastropods, you know the tooth-studded radula is a diverse and effective organ to acquire food. But scraping and drilling are just a few of the adaptations among marine snails, and this ruggedly handsome Cooper’s Nutmeg snail (Cancellaria cooperi, Cancellariidae) has another trick. Its sharp, almost scalpel-like teeth bite a small slit into their sleeping prey, and when the prey begins bleeding, their proboscis is pressed against the wound to casually sip the flowing blood. A vampire snail on its own seems earn

enough weirdness points, but it doesn’t stop there. Cooper’s Nutmeg seems to be an ectoparasite specializing on the California Electric Ray (Torpedo californica), a fish with high enough voltage to knock out any potential prey and foe alike, but somehow it doesn’t seem to detect the snail. Experiments in aquarium settings, as well as observations in the wild, suggests this snail specializes only on electric rays, with some observations showing over a dozen snails feeding simultaneously off a single ray, and has yet to be documented feeding on any other species of fish.

Cone of Silence

Last up in our series of marine gastropods and their strange adaptations for feeding is a good candidate for the next campy horror film. You may remember from past episodes that

cone snails (Conidae) have a highly-specialized harpoon-like radula and associated venom gland that makes them highly toxic predators. The Geography Cone (Conus geographus) is a slow, silent hunter on the midnight reefs where it seeks out sleeping reef fishes (yes, fish do sleep) by their acute sense of smell. Once within close range of a fish, the large mouth, really an expandable funnel-shaped shroud, releases a complex cocktail of nearly two dozen different paralytic toxins called the “nirvana cabal” including insulin that causes the prey to become lethargic by creating hypoglycemic shock, like the knock-out gas in an old James Bond movie. When the dazed fish is engulfed by the mouth, the harpoon is fired into the fish, quickly killing them. One look at the aperture of the shell shows an opening much wider than most other species of cone snails, and this allows the snail to swallow the entire fish into the main chamber of the shell. While their venom is primarily used for prey capture, it can be turned defensively on their predators. In fact, the Geography Cone is regarded as one of the most venomous of marine animals, and is responsible for no less than 30 documented cases of death in humans, though the actual number is likely much higher since traces of the venom are difficult to detect and effects of the toxins may mimic other more common causes of death, like heart attack.

The post Malacology Monthly: It Eats Whaaaat? first appeared on Deep Sea News.

At the heart of downtown Oakland, San Francisco’s stereotypically grittier and unpolished sister city across the San Francisco Bay, lies an urban lake that is experiencing a remarkable rebirth. Lake Merritt isn’t so much a lake as it is a contained, urbanized arm of the Bay itself. It is a brackish-water lagoon divided from the cement sphincter of sky scrapers and apartment buildings by narrow strips of oak-studded parkland. I’ve lived by the Lake for the greater part of three decades, and while it hosts a flotilla of migratory ducks in the spring & fall, it was a figurative dead-zone devoid of the rich marine life in the Bay, and sometimes a literal dead-zone when bodies were dredged out of the muck. While making a picturesque and relaxing place to hang out on a warm summer night, the summer days often stank of rotting invasive algae and sulfur-producing bacteria.

In precolonial times, expansive shellmounds around the slough attested to the abundance of shellfish and game that allowed the native Ohlone peoples to thrive. Even with the influx of settlers into the mid-1800’s Lake Merritt was still a functioning part of the San Francisco Bay Ecosystem, The Lake was a vibrant tidal slough that brought migrating salmon to Oakland’s creeks, with historic records of river otters, harbor seals, and enough ducks to host several hunting clubs. Encroaching urbanization morphed scattered clusters of Gold-Rush farms, factories, and merchants into a bona-fide city, forcing changes to the Lake. A cement lining replaced the muddy banks of the slough, and a gated dam was placed at the connection with the Bay in an attempt to mediate the flooding from heavy seasonal rains. In 1870, Lake Merritt was declared the nation’s first wildlife refuge, but such a title didn’t guarantee special protection. Urban runoff carrying sediment and pollution produced a shallow, mildly toxic environment that often became too warm and anoxic in the summer, and too laden with fresh water in the winter, to maintain any real biodiversity. With more residents came more waste. For several decades in the mid and late 1880’s, Lake Merritt was the sewage system for much of downtown Oakland, causing such a literal stink that the federal government intervened to correct the health concerns associated with floating islands of waste and banks caked with human excrement.

Despite this, Lake Merritt remained both a source of civic pride and a focal point for many of Oakland’s social and municipal events. It’s not surprising that in 2002, bond measure DD was approved by more than 80% of Oakland voters, creating a fund of almost $200 million that would renovate much of the city around the Lake from its urban creek headwaters to its connection with the San Francisco Bay, restoring Lake Merritt into a functional ecosystem. Pots of money from this initiative restored the crumbling infrastructure of the Lake, placed trash filters that caught litter carried by curbside gutters, and provided more public education about the health and ecology of the Lake. More importantly, dredging the Lake and modifying the canal that connected it to the San Francisco Bay flushed fresh ocean water with every tide, feeding cool, oxygenated, nutrient-rich water into the Lake.

It took a decade after public approval of the bond measure to begin full implementation, but when it did, results were quick and dramatic: schools of silverside and jacksmelt boomed, feeding growing numbers of terns, herons, and kingfishers. Young steelhead salmon were seen for the first time in decades, as were California Bat Rays feeding on the growing clusters of native and non-native mussels. River otters were spotted for the first time in a century. The real testament to the ecological invigoration of the lake were the lush and diverse gardens of marine algae, and the giant sea hares they fed.

Sea hares, specifically the California Sea Hare (Aplysia californica), are large slug-like gastropods that lack a shell, but make up for this minor shortfall in sheer slimy bulk. As California’s largest gastropod, they can measure two and a half feet long, and weight up to 15 pounds. This year Lake Merritt hosted a population boom of the animals for the first time in my recorded memory of observing the lake. Promoting a natural tidal cycle created a cascade of new colonization. The saltwater influx from the Bay improved conditions and nutrients that produced abundant algae growth, and also brought tiny larval sea hares into the Lake to settle and feast on this algae. This year, their population got a bit of a boost with warmer El Nino waters bringing even more larvae than usual into the Bay. As the sea hares grew into their brown, tan, purple, and green super burrito sized adult stage, they mingled in large orgiastic masses of mating and egg-laying. Being simultaneous hermaphrodites, the sea hares piled into groups of two to two-dozen, exchanging sperm and egg with each other, and leaving behind long strands and woven clusters of neon-greenish yellow eggs.

On a particularly sunny July Saturday, the Lobos Marinos and I hosted an informal community-based interpretation of more than 171 sea hares along the eastern bank of Lake Merritt, where hipsters, hip-hoppers, yuppies, young families, and old couples wanted to know what the heck these things were. The main question was “can you eat them”, to which I relied “yes, you can eat them, so long as you don’t mind their poison glands”, but the no-fishing policy at the Lake actually prohibits the take of sea hares. Some people thought them interesting though a bit disgusting, while others, after learning how Oakland citizens voted to restore Lake Merritt, felt a little more of that Oakland pride. For me, an Oakland taxpayer, renewing the Lake back into a vital ecosystem was worth the money. Today, more than three months later, the boom of sea hares is over. The last breeding adults are at the end of their short lives, with those before them leaving behind decaying masses of mucus. Winter rains will reduce the salinity of the Lake, yet this surge will flush the newly-hatched larvae back into the Bay. Lake Merritt’s restoration will continue for several more years, but with the next summer, the sea hares will hopefully return.

The post How Urban Renewal Gets You Giant Sea Hares first appeared on Deep Sea News.

Scorpion Without a Sting

This leggy shell belongs to a group of gastropods called the Spider Conchs, and this particular species is the Scorpion Spider Conch (Lambis scorpio), which can neither bite nor sting. The group gets its name from the leg-like extensions along the edge of the expanded opening of the shell (aperture) that serve no function in locomotion. Living in the intertidal and shallow subtidal mud, sand, and coral rubble where the surge of waves can be intense, researchers believe these spines serve to prevent the snail from rolling on the bottom. As an added benefit, long, thick spines could make it more difficult for mollusk-eating fish to eat the Scorpion Spider Conch. But as nobody has ever conducted any field studies or laboratory simulations of how these spiny shells actually function, they are untested assumptions. If scientists knew everything, there would be no work for graduate students.

Spiny Shield

Limpets rarely get much respect among malacologists, let alone shell collectors, yet they have a subtle magnificence. I bring you the Bearded Limpet (Scutellastra barbara; Patellidae). Mollusks that live in the intertidal zone are the cage-fighters of the invertebrate world. You’ve got to be extra tough to withstand tons of force from a crushing wave, survive the hot and dry exposure from low tide, and have sure-fire ways to avoid being eaten by predators both on the land and in the water. This shell has a series of strong ridges that radiate out from the crest of this pyramid-like shell to the outer margins of the shell. Architecturally, these ridges act as girders not just strengthening the shell, but directing the power of a breaking wave to the outside edge of the shell. This causes the power of the wave to be divided across the shell along these girders, but since these ridges end in spines that are in contact with the rocks, the wave force actually causes the shell to be pressed against the rock, holding it in place as the wave is breaking around the shell. Further, the bumpy, spiny edge of the shell could also make it harder for limpet enemy number one – the African Oystercatcher – to eat it. The bill of the oystercatcher is shaped like the flat end of a standard screw driver, and the oystercatcher wedges this sharp edge under the shell and pries it off, flips it over, and scrapes out the fleshy tidbits. The uneven spiny edge makes it much more difficult for the oystercatcher to slip the bill underneath the shell, and theoretically a few more Bearded Limpets survive to pass on this morphology to the next generation.

Twice the Spines, Twice the Fun

The Spiny Oysters (Spondylus: Spondylidae) such as this dandy Spondylus foliaceus, are a widespread group in tropical and subtropical waters, shallow and deep seas, with a diversity of colors and shapes, but they are all united in the spines, thorns, and prickly bits that cover their shell. The function of these spines, as imagined by unimaginative malacologists, it to protect the oyster from piscine predators, but that’s what they always say. Three other possible ways that could potentially increase the survival of the spiny oysters are as follows: (1) these spines could act to deter the settling of barnacles, anemones, and even other oysters on their shell. Acting as a figurative layer of barbed-wire the spines keep other large invertebrates from plopping-down on their shell and growing on them, weighting them down, and competing for food; (2) the expanded surface area these spines provide could promote the settlement and growth of other small marine organisms. Algae, bryozoans, and encrusting sponges, could provide a natural camouflage to better conceal these oysters on the sea floor; and (3) these spines could act as a ‘baffle’ to slow water flowing around the clam. As you all remember from your hydrophysics courses, moving water carries objects (sand particles, plankton, delicious detritus, etc.), and the faster the water moves, the larger particles and the greater number of particles the flow can carry. If there are impediments to water flow, such as dozens of spines on an oyster’s shell, the water slows and drops its particles. So, the spiny oyster’s spines may act to slow moving water around it, and that water would drop its suspended detritus and plankton right around the edge of the shell where the oyster is drawing in that water to filter out a meal. Or maybe it’s just to deter fish from eating them after all.

Shell Superstar

Behold the Japanese Star Turban shell (Guildfordia yoka; Turbinidae), a flat and radially spiny gastropod from the western Pacific Ocean that looks like a nasty weapon hurled in a kung-fu movie. One hypothesis concerning their spines is that it helps to distribute the weight of the snail outward so that it doesn’t sink into the soft deep-sea muds where it lives. Where broad, flat spines might accomplish this feat, their thin, narrow spines would seemingly cut into the soft mud, offering no real support for the weight of the shell in the center. But dang it if those spines don’t give up clues themselves; because they often show signs of breakage and regeneration, like one of the spines seen in this shell, they are likely for protection from predators. If the spines don’t actively repel foraging deep-sea fishes by a painful jab in the roof of the mouth, the spines may simply make the snail too big to even swallow in the first place. When the Japanese Star Turban survives a potential attack with a few spines broken, the snail will repair or regrow the protective spines to live another day.

Spines Fit for a Goddess

Sorry that I didn’t mention there would be a final exam for the end of this post, so sharpen that No. 2 pencil. Spines on shells, much like a Swiss army knife, can serve one or many functions. They deter predators, strengthen the shell, and support the animal in various ways. But this gastropod shell, the Venus Comb Murex (Murex pecten; Muricidae) is the most glorious example of spines. As the name might suggest, it is the natural comb that keeps a sexy Roman goddess’ hair smooth and manageable. After all, as legend has it, Venus was born of sea foam, and you can imagine what ruin the tides can do to her hairdo. But no, none of the ancient texts or depictions in paintings, mosaics, or bas-reliefs show Venus using this shell as a styling tool. So then, what evolutionary, ecological, and/or morphological function do you expect the spines to serve? Watch the video below for some clues:

The post Malacology Monthly: Spines and How to Use Them first appeared on Deep Sea News.

Bivalves: clams, scallops, oysters, cockles, and mussels, have rich lives and complex evolutionary histories far beyond the deep-fryer. Here are vignettes of four bivalves that provide a small glimpse into their world. So next time you order the frutti di mare linguini, ponder for a second what you are about to eat.

Smart Scallops
Edward ‘Doc’ Ricketts, renown marine biologist and friend to full-time novelist and part-time alcoholic John Steinbeck, once stated: “next to the octopus, the scallop is the ‘cleverest’ of all the mollusks”. While I don’t entirely agree with that remark, I do concur that scallops are perhaps the most interesting of all the bivalves, like these polychromatic Noble Scallops (Mimachlamys nobilis). What makes scallops (Pectinidae) unique among the bivalves are their

baby-blue eyes, ones that would give a Frank Sinatra a run for his money. Surrounding the open-end of the shell in upper and lower rows as a vigilant arcade, these simple peepers can detect changes in light and perceive basic movement, warning the scallop of advancing predators. Their response is to flee by snapping the two sides (valves) of their shell like crazy zombified castanets, scurrying in zig-zagging movements away from the imminent threat by forcing out strong spurts of water every time the shell snaps shut. While these sudden movements may not be guided in a specific direction, the main goal is to get the scallop way from what may hope to eat it, which usually propels them far enough from harm’s way.

Adaptations for this snap-and-zag escape consist of a wide, flexible hinge at the back end of the shell, and a single adductor muscle that can quickly pull the two halves of the shell together. It is this muscle, making about 20% of the soft tissue inside the shell, that one eats as the ‘scallop’ in a seafood platter, with most of the remaining flesh discarded. Most other non-western countries relish the extra innards of the scallop, especially the swollen and succulent gonads during the scallops’ mating season, but those in the more industrialized nations can afford to waste what is perfectly edible. And ironically, while the tasty adductor muscle may be the key in a scallop’s escape from a predator, it doesn’t work so well when trying to flee the path of a 30’ beam trawl dragged along the bottom of the sea.

Boring, Boring, Boring…

Clams can be boring, really boring. No, really, boring. Some species bore into packed mud and some bore into wood or even whale bone, but the Warty-necked Piddock (Chaceia ovoidea) can actually bore into solid rock. Larval piddocks settle into small cracks or existing holes in the rock, and as the shell grows, the posterior portion of the shell develops rows of rough ridges that act as a rasp, and the clam uses it’s muscular foot to bump and grind, literally drilling into the sandstone, shale, and limestone on the ocean floor. As the clam continues to grow in size, it’s burrow becomes an inverted funnel, with the original hole opening to the outside, and a larger interior den that increases in size as the clam’s shell grows and constantly scrapes and remodels the inside of its home. Though it can never escape its clam cave, it lives a simple life of a filter feeding bivalve by extending two large fleshy

siphons out the front door that look like a tunicate. The larger incurrent siphon (the gazin) sucks water and suspended food into the body for filtering, and the smaller excurrent siphon (the gazout) flushes the filtered water outside of the clam’s shell. While their means of feeding isn’t impressive, their bivalve superhero ability to literally drill into solid rock should convince some of you that boring clams certainly aren’t boring. But what about sex? Celibate clams cloistered in a stone cell?  Easy, fertilization is external, with males & females releasing sperm and egg simultaneously during particular spring tides.

Motherly Love
For Mother’s Day, we in the Malacology Monday team honor all those mothers out there, present and past. I experienced much too recently the impermanence of one’s mother and the void it leaves in the heart, so perhaps this True Heart Cockle may fill that hole for those of us who have lost their mother. This heart is full of motherly love. The genus name Corculum means ‘darling heart’ in Latin, and the species name cardissa is the Greek word for ‘female heart’. Their family of bivalves is the Cardiidae, meaning ‘heart’ in Greek, and they are a member of the larger taxonomic group Veneroidea, stemming from the Latin venereus, derived from Venus, the goddess of love, which is most likely how you were conceived by mom in the first place. But Corculum cardissa is not like most mothers. The True Heart Cockle is a hermaphrodite, not an uncommon method of reproduction in the invertebrates, but a rare method of producing young among the bivalves. As Corculum expels an egg, it is carried away by the currents and rapidly develops over the next two days into a miniature copy of the mother it will never see again. In the meantime, mother has an adopted family of her own microscopic dinoflagellate algae living in her tissues. Her semi-transparent shell acts as a tiny greenhouse protecting these adoptees who pay their respects by manufacturing food through photosynthesis that supplements what other food particles she strains from seawater through her gills. What she lacks as an absentee mother for her own spawn, she makes up for as the caretaker to hundreds of tiny dinoflagellates.

Heavyweight Champion of the Bivalve World

The Malacology Monday team was recently on expedition deep into tropical malacology. The highlight of our explorations along the Great Barrier Reef were dives with the giant clam (Tridacna gigas), from wee ones smaller than an Oreo cookie, to some massive old guardians of the reef that were near record size. This clam is the largest bivalve alive today, with their shell reaching over 1.3 meters (4.2 feet) wide and weighing a whopping 331 kg.(730 lbs). While they are indeed clams, they live more like corals, housing symbiotic photosynthetic zooxanthellae in their large, brightly-colored fleshy mantle, which look like Mick Jagger’s swollen lips after being decked by an enraged Bianca. But these lips, like the mantle of the Heart Cockle (above) house the millions of

tiny algae that convert tropical sunlight into food energy, sharing it with the clam and supplementing the clam’s diet of filtered detritus and plankton to keep it alive. For that reason, these clams must live in the warm and intensely light shallows of the tropics where they can be abundant enough to be the dominant component of some reefs, even exceeding coral in biomass and coverage. While the giant clam population around the Great Barrier Reef appears stable, with even the largest clams seemingly abundant, pollution, sedimentation, dredging, and collecting clams directly for food or sale into the curio trade, giant clams elsewhere are declining or even wiped-out entirely. Australia, however, has been pioneering the aquaculture of giant clams, and have successful long-term projects to re-populate reefs in the South Pacific with these massive mollusks.

The post Malacology Monthly: A Look at Bivalves, From Both Sides Now first appeared on Deep Sea News.

Recently a friend brought to my attention that the Internet was losing its collective mind over “sea bunnies”. Googling, “sea bunny” I found articles at International Business Times, Metro, RT, Apex Tribune, Weather Channel (wait what?), The Dodo, HuffPo, Geek, Women’s Day (umm), and The Telegraph.

Well gosh darn it! How to I jump on up on this bandwagon? DSN has been suffering from low clickage lately and we could use some of that sweet, sweet tasting clickbate. So bring on a whole damn field of SEA BUNNIES! Because precious few of these websites actually include any information about the animal, I said to myself “I’m gonna science all over this!” So pull up a chair kiddo’s and prepare yourself for an invertebrate biology braingasm. I’ll provide this as a clever top ten list too so I can be super trendy.

1. The sea bunny is actually a nudribranch, aka a sea slug, called Jorunna parva. They are also quite small, less than one inch in length.
2. Jorunna parva is 1 of 16 species in the genus and the only one that looks like a bunny. Some of the other species are little less…dandy, others very post modernist, and some have gills that look like brown wilted lettuce.

3. 

   The furry looks comes tons of caryophyllidia across the back of their bodies, aka the mantle.   Caryophyllidia are fleshy protuberances, papillae, that bear a crown of pointed spicules used for sensory functions.

4. The dark colored bunny ears are not actually ears but rhinophores. As the “rhino” would suggest these are sensory organs on the head used for chemoreception. In the group of nudibranchs that contains the sea bunnies, the rhinophores are particularly “fuzzy” allowing for more surface area for this reception to occur on.
5. The color pattern is crazy variable in Jorunna parva. Very few individuals are actually white with black patches. Most are dark yellow (like a Peep?). Some individuals can even be dark brown (mmm chocolate bunny) surrounded in a band of dark yellow.

6. 

   The famous Japanese scientist Kikutaro Baba named the species in 1934. Baba was a renowned and prolific malacologist, i.e. a scientist who studies mollusks, who described 116 species and has 14 species and taxa names after him.

7. There is some confusion what nudibranchs are and are not actually Jorunna parva. Mollusk geeks, of which I count myself, are unclear whether the extreme color variation actually represents different species. This could mean the difference between the species being distributed throughout Japanese, Northern Australian, and the Indo-Pacific oceans or isolated to a small area. It is worth noting the white fluffy bunny with the dark ears version of Jorunna parva seems to be primarily off the coast of Japan. (see these posts at the Seaslug Forum)
8. Jorunna parva may show some California love. J. parva bears many striking resemblances to J. pardus off the California coast. Some sea slug experts think they may be one in the same.
9. They are hermaphrodites. Well technically, all nudibranchs are. So mating like bunnies is actually much easier since they don’t have to be so choosy. Any other bunny will do.
10. They are very, very hungry. Recent work in my lab has shown for nudibranchs only exist where there is a lot of food. This may be because being a hermaphrodite is calorically expensive, an individual needs to produce eggs and sperm continuously

The post The Science of Sea Bunnies: You’ll Never Believe The Top Ten List We Created To Get You To Visit Our Website. first appeared on Deep Sea News.