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.

At beginning of  a Gastropod’s life, at the tiny larval stage (the veliger), the parts of the body begin to rotate.  Not of all them, just the organs for digestion, reproduction, circulation, the shell, and the body wall that covers the former and secretes the latter, twist 180˚ counter clockwise.  This process, called torsion, eventually places the organs previously on the right side on the left. The central nervous system becomes a pretzel.  Torsion quite literally ties the snail’s stomach in knots with the whole gut eventually twisted into a U-shape. This gut spin also has the unfortunate consequence of placing the anus right above the snail’s head in proximity way to close to the gills.

Why evolution has favored this round robin of body parts in Gastropods, and how exactly it occurs is a fascinating story and one not yet fully understood.    In 1929, Walter Garstang, proposed a hypothesis both for how and why torsion occurs.  Garstang was born in 1868 in England and ascended the ranks of academia to work on everything from slugs to sand crabs to sea gulls.  His life’s work is divided into three periods: the first occupied primarily with pure marine biology and larval development; a second devoted to fishery investigation of which he is pioneer; and third as full professor and into retirement concentrated on fundamental problems in zoology and evolution with ventures into bird song.  As noted in his obituary, in 1949, he was a poet and lover of nature.  And although noted for many things, Walter Garstang, is probably best remembered for his poems about form, function, and development in invertebrates.  A collection of his poems was published two years after his death as Larval Forms and Other Zoological Verses, an epic volume that resides in a special spot on my and other zoologist’s bookshelves.

In a poem about Tunicates or sea squirts, Oikopleura, Jelly Builder, Garstang waxes poetically,

A filter in front collects all the fine particles

Micro-flagellates and similar articles

Which pour in a stream through a jelly-built tunnel

Into its mouth and its mucillage funnel.

However best known among his prose is The Ballad of the Veliger or How the Gastropod Got Its Twist, a 400 word poem dedicated to and explaining torsion in Gastropods.

The Veliger’s a lively tar, the liveliest afloat,

A whirling wheel on either side propels his little boat;

But when the danger signal warns his bustling submarine,

He stops the engine, shuts the port, and drops below unseen.

He’s witnessed several changes in pelagic motor-craft;

The first he sailed was just a tub, with a tiny cabin aft.

An Archi-mollusk fashioned it, according to his kind –

He’d always stowed his gills and things in a mantle-sac behind. 

Young Archi-mollusks went to sea with nothing but a velum –

A sort of autocycling hoop, instead of pram – to wheel ’em;

And, spinning round, they one by one acquired parental features,

A shell above, a foot below – the queerest little creatures. 

But when by chance they brushed against their neighbours in the briny,

Coelenterates with stinging threads and Arthropods so spiny,

By one weak spot betrayed, alas, they fell an easy prey –

Their soft preoral lobes in front could not be tucked away! 

Their feet, you see, amidships, next the cuddy-hole abaft,

Drew in at once, and left their heads exposed to every shaft.

So Archi-mollusks dwindled, and the race was sinking fast,

When by the merest accident salvation came at last.

A fleet of fry turned out one day, eventful in the sequel,

Whose head-and-foot retractors on the two sides were unequal:

Their starboard halliards fixed astern ran only to the head,

While those aport were set abeam and served the foot instead.

Predaceous foes, still drifting by in numbers unabated,

Were baffled now by tactics which their dining plans frustrated.

Their prey upon alarm collapsed, but promptly turned about,

With tender morsel safe within and the horny foot without!

This manoeuvre (vide Lamarck) speeded up with repetition,

Until the parts affected gained a rhythmical condition,

And torsion, needing now no more a stimulating stab,

Will take its predetermined course in a watchglass in the lab.

In this way, then, the Veliger, triumphantly askew,

Acquired his cabin for’ard, holding all his sailing crew–

A Trochosphere in armour cased, with a foot to work the hatch,

And double screws to drive ahead with smartness and dispatch.

But when the first new Veligers came home again to shore,

And settled down as Gastropods with mantle-sac afore,

The Archi-mollusk sought a cleft, his shame and grief to hide,

Crunched horribly his horny teeth, gave up the ghost, and died.

Garstang’s hypothesis about Torsion was that it occurs in two steps.  The veliger possesses two retractor muscles.  One of these extends from the shell on right, over the gut, and attaches to the left side of head and foot.  The other starts on the left and attaches to the right.  Garstang proposed that these muscles were asymmetrical in their size and strength.  The right-to-left retractor causes the larval shell to twist the first 90˚ in a matter of minutes.  The second 90˚ requires deferential cellular growth to accomplish.  Garstang suggested further that torsion was an adaptation for protection.  Without torsion, larval snails would retract into the shell tail first leaving the head and other important parts exposed to the teeth, claws, and tentacles of hungry predators.  With torsion, larval snails would retract the head first.  And in the grand coup d’état that was characteristic of so many of Garstang’s bold evolutionary hypotheses he offered one additional item.  That evolution of no torsion to torsion all occurred through a single, not an accumulated set, of mutations.

Over 80 years later, what has happened to Garstang’s Torsion Hypothesis?

As one author put it 1958 “more controversy has been devoted to the adaptive explanation [of torsion] than to any other point to of molluscan biology.” (Morton 1958)  More recently in 1992 another author noted that torsion is still one of the “grand traditional controversies among malacologists [that] have not been resolved.”  (Beiler 1982)

Much like a snail, the story of understanding their past, is also full of twists.  Walter Garstang himself is both praised and belittled. “He often appropriated the ideas of others without attribution, ignored earlier studies conflicting with his theories, and clung to [outdated scientific ideas]” (Holland 2011).  Indeed, Garstang’s Torsion idea and others, may largely live on “chiefly though their perpetuation in numerous textbooks” (Gee 1989) and their importance colored by obituaries and commentaries on his work written by his son-in-law.  As Stephen J. Gould wrote, “We cannot blame a man very strongly for lavishing too much praise on his father-in-law.” Alternative hypotheses, including one that requires a land dwelling octopus, have come and gone, and in rarer cases stayed only after dueling with the Garstang’s ghost.

Check in next week for Part 2!

The post How the Gastropod Got Its Twist first appeared on Deep Sea News.

Horrific sexual hijinks are taking place beneath the majestic redwoods of central California! I’m not talking about San Francisco – the Fulton Street Fair looks like a Bible Belt county fair compared to this. No, I speak of the unspeakable sexual habits of the lovely banana slug.

The banana slug, so called for its fetching yellow color with occasional black spots, is the second-largest slug in the world (and the mascot of UC Santa Cruz). For most of its life, it crawls about the Pacific redwood forest in the normal sluggy fashion, munching upon rotting leaves, mushrooms, animal droppings, and other detritus. But if a slug crosses the pheremone-soaked slime trail of a fellow slug, prolonged tantric slug-sex ensues…and ends in a most ghastly fashion.

Before we get to the juicy bits (slimy bits?), you need to know a bit about slug anatomy. Most slugs are simultaneous hermaphrodites and have both a penis and a genital opening, so that when they have sex they both fertilize and are fertilized. (They then both lay eggs somewhere damp and out of the way, and that is it for parental care.) Also, due to the vagaries of evolution, the genitalia and anus of slugs are located on the right side of their heads. This is because slugs are descended from snails with spiraling shells – the snails needed to move their naughty bits down in order to extend outside the shell, so they put them on their head. Even though slugs have since lost their shells, they have retained this feature of snail anatomy. So most gastropods actually poop on their own heads – ain’t nature grand?

So, slug-sex begins with head-waving and gentle biting of the other slug’s genital opening. Once they get to the Big Deed, the slugs both insert their penises into the other’s genital opening (remember, both are on the right side of their head) and go at it for hours and hours. And hours and hours and hours. And then…sometimes…one or both slugs will CHEW OFF THE OTHER’S PENIS. Yep, they rasp with their radula until the penis comes off. Then they slurp down the penis like spaghetti.

I bet your very first reaction was, “Boy, I sure hope there is a video of sexy slug cannibalism!” Of course there is, gentle reader! If you still want more, have some auto-apophallation (isn’t that a great bit of jargon?) – this is a video [warning: big file] of a slug chewing off its own penis.

Do not fear too much for the penis-less slug. While the penis does not grow back, the slug is not condemned to a lonely sexless life. It can still enjoy slug-sex as the receiving party. But perhaps the more educated banana slugs contemplate the theories of Freud and shake their tentacles in rage at the cruel hand of Fate. Or at least the cruel radula of their ex.

This post was inspired by the slugs in flagrante in the above photo, which I met near the Little Sur River this past weekend. (The openings you see are not their genitals, but their pneumatostome, which is how they breathe.) It is unknown if any penis-gnawing ensued, as the slugs were still making the sweet yin-yang of love amidst the flowers when I left.

The post Perverted cannibalistic hermaphrodites haunt the Pacific Northwest! first appeared on Deep Sea News.

Science at FMNH – Exploring Unknown Deep Sea Ecosystems from Science at FMNH on Vimeo.

The post Janet Voight: In 1860s “Educated People Could Not Envision” Life on the Seafloor first appeared on Deep Sea News.

The Weeping Angels are the monster of the week in one of my very favorite Doctor Who episodes. They look like saccharine angel statues…until they strike.

The Weeping Angels could very well have been modeled off the lovely sea angel, if the Doctor Who writers are secret marine biology fans. Sea angels (Clione spp.) are adorable shell-less molluscs that fly though the water on cute little wings, looking like this. Awwww!

Except when they’re hungry. And they uncurl the first third of their gut, shoots tentacles out of their face, rip the bodies of their prey (shelled swimming molluscs called Limacina) out of their shells, and shred them with their sharp radula.

Natalia Chervyakova of Moscow University got absolutely stunning photos of Clione hunting Limacina. I can’t embed them because they are in Flash, but go here right now. Or you can watch the Japanese game show version below.

I think I would prefer being chased by the Weeping Angels, myself. Because Clione don’t care if you blink.

Thanks to Jesse for sending the photos!

The post Angels in Antarctica first appeared on Deep Sea News.

I first discovered Dr. Pat Krug when he gave a talk at Scripps and revealed that he had named a new species of sea slug after Willow from Buffy the Vampire Slayer in order to “capture the spirit of sexual flexibility.” Now Dr. Krug is back with a great interview about the importance of discovering new species, and of course the sex life of slugs.

But the best part of the interview is a song about the “solar-powered sea slug” Elysia chlorotica. Don’t know what that means? Listen to the song by KPCC’s Sanden Totten. It’s the second stream on the little embedded player, or you can download it here.

Tip of the tentacle to Jann Vendetti!

The post The Slug Song, and more from Dr. Krug the slug drug lug first appeared on Deep Sea News.

Geerat Vermeij’s new paper “Sound reasons for silence: why do molluscs not communicate acoustically?” is a thought exercise on the adaptive possibilities of life. The deliberate production of sound for communication is known in arthropods and vertebrates. But why not in the over 100,000 species of mollusks ranging 11 orders of magnitude in size that occupy just about every niche on earth from marine parasites on sea cumbers to tree dwellers?

For a new adaptive trait to appear first the appropriate genetic material or developmental infrastructure needs to be in place. Second, selection must favor the novelty.

Why would mollusks even need to produce sound? The deliberate production of sound is used to attract mates, ward of predators, locate prey, and in social communication. Of course there needs to be recipients to hear and interpret the sound. The actions of the recipient must also be predictable from the emitted sound of the producer. One of these criteria falls and sound moves from communication to noise.

Organisms that release their sperm or eggs into the water, like many molluscs, don’t need to attract a mate. On the other hand, many gastropods and cephalopods do internally fertilize so mate attraction would be important. Some of the main predators, i.e. crustaceans and vertebrates, use sound for communication and thus are able to detect sound. Yet sound detection by another major predatory group on molluscs, the echinoderms, is lacking.

Detection of sound is a mechanical ability. In the human ear, sound waves are ultimately transmitted to the cochlea where hair cells detect the mechanical movement and convert it to a chemical signal. Sound and vibration detection is known also in molluscs. On the tentacles of gastropods sensory cells can detect vibration. Cephalopods possess an equilibrium organ, the statocyst, which detects movement with the changing position of hair cells. Coquina, that colorful and tasty little bivalve common on Florida and Caribbean shores, when sensing the vibrations of coming wave will jump out of the sand to ride it. A common intertidal gastropod, the Nerite, is known to fall off boulders back into the water when humans approach.

Sound production is known in molluscs. Kitting in 1979 noted that the varying sounds produced by limpets and snails scraping algae from rocks while feeding could be used to distinguish species. The variation in sound stemmed from differences in the structure and movement of the teeth, i.e. radula. In perhaps the best example, a gastropod in Hong Kong will strike its shell against the rock when predatory snails or sea stars attack it. But it is unknown whether the sound production is intended for predator warding or simply the outcome of another anti-predator behavior, e.g. moving the shell to make predatory capture more difficult.

But if an animal produces sound it risks detection. In the animal kingdom passive defenses and defensive sound production often do not go together. An animal must back a sound up with a quick escape or the ability to confuse or resist the attacker. These are active defenses, which while common in cephalopods, are not common in other mollusks. No molluscs are the kings of ultimate passive defense…the shell. High speed escapes among molluscs like snails and bivalves are rare and most do not have the metabolism to produce athletic activity. Exceptions do exist like the scallop that can swim away, razors clams that can quickly bury themselves deeper, swimming sea slugs, and of course the cephalopods. But, those mollusks capable of fast escapes lack the raw hardware to produce sounds. They are often soft-bodied mollusks lacking a shell or air filled spaces that could produce sound. Interestingly, many of the predators of molluscs, for example sea stars, aren’t fast moving themselves.

O’ but if molluscs could acoustically communicate, who would be the prime candidates? Vermeij suggest that molluscs with co-optable structures are the cephalopods with their beaks and quick movements. But a snail contender is also present. With internal fertilization, a shell, and operculum (the little calcareous shell door that many snails have), some of the quicker moving predatory gastropods might be having whole conversations we don’t know about.

Christopher L. Kitting (1979). The use of feeding noises to determine the algal foods being consumed by individual intertidal molluscs Oecologia, 40, 1-17 DOI: 10.1007/BF00388806

Geerat J. Vermeij (2010). Sound reasons for silence: why do molluscs not communicate acoustically? Biological Journal of the Linnean Society, 100, 485-493 DOI: 10.1111/j.1095-8312.2010.01443.x

The post If Molluscs Could Communicate What Would They Say? first appeared on Deep Sea News.

The post Giant. Freaking. Clams. first appeared on Deep Sea News.

So without further ado, the 10 reasons why Molluscs are the best.

• More body size range than any other group. The biggest invertebrate? A mollusc!  And it has hooks!
• Way over 100,000 molluscs! [Insert your comment about how there are millions of arthropods here] Blah, blah, blah…they all look the same and that is some lame estimate based on beetles.
• Fear and respect the radula
• Snails with hair.  We got them! Snails with iron.  We got them!  Snails with spikes that are just plain bad ass.  We got them to!
• They will eat your wood, suck out your innards, and gnaw on your gills!
• Hermaphrodites, multiple partners, and sequential lovin’!
• Aplacophoras…I bet you didn’t even know about these? They are like crawling bristle brushes.
• Bernoulli referred to it as the miraculous spiral and others referred to it as the golden spiral for its relation to the golden ratio and Fibonacci numbers.  The logarithmic spiral possesses unique mathematical properties such that as the size of the spiral increases the shape remains unaltered. You can’t throw a Bernoulli or a Fibonacci without hitting one in the molluscs!  Where else to they occur in metazoans?  No where!
• Because of this, this, and this!
• Vampire squids from hell!  HELL!

Make sure you stay tuned here for updates as the situation develops and the #invwar hashtag on Twitter

The post Molluscs, now with 100% more awesum first appeared on Deep Sea News.

When we all funded “X”, Eric revealed the “Y”:

Making Waves, Oceans and Landforms – Ace of Diamonds

Coral Reef Flipbooks – Queen of Hearts

Waders for Water Quality Studies and More – Jack of Diamonds

You will have to go there to check out the cards and the excellent, well-written posts that accompany them! Eric worked very hard on these and any fan of the Invertebrata will be impressed. We’ll keep a running list of the cards as more projects get funded. Just another reason to give to the Ocean in the Classroom Challenge! Just imagine if we were able to fund 52 PROJECTS!!!

Get out your wallets and help out struggling teachers and impressionable youth. I have, and so have many others including Danna S, Dr. H, Jarrett B, Christina K and Michael R, as well as Craig and Tim who made good on their challenges. The Moss Landing Marine Lab Blog has also joined in the fray with this great post!

“A major part of science is collaboration, because some projects require more effort, resources, or people than one lab can handle.  Collaborating allows us to tackle bigger projects and tasks than what would otherwise be possible.  The folks at Deep Sea News organized a collaboration with many other marine science blogs to sponsor support of K-12 marine science education.”

Let’s keep the momentum going. If you haven’t donated yet, what is holding you back? What reservations do you have? Lack of money? Do you hate schools or teachers? Hate children? Hate the ocean? Why hate? Just love! Perhaps if you fully fund a project yourself you will become filled with the love and excitement and enthusiasm for the ever-so-important 71% of of our planet’s surface that these kids should have the opportunity to feel when they are out on a tall ship for the first time hoisting ropes, singing shanties, pulling in plankton nets and learning how our oceans work!

The post Behold the Jack of Diamonds! first appeared on Deep Sea News.