Are you old enough to remember the show MTV Cribs, where a camera crew invades the home of a filthy-rich celebrity and takes annoyingly jumpy quick-shots of how awesomely decked-out and unnecessarily opulent their ‘crib’ is? Think about that approach, but with a Malacology Monday twist. Firing up a band-saw and with the warnings of my old school shop teacher “you’re gonna cut your thumb off” echoing in my head, our team will show you inside the ‘cribs’ of Malacology’s most interesting species.

High-Rise House
First up, the aptly-named Screw Turritella (Turritella terebra: Turritellidae) with a tall, twisting spire. For gastropods, the shell is a home that offers protection to withdraw into when needed, and as the muscled-mass of the snail grows, so too must the shell. The opening – or aperture – of the shell is the front-door, and new shell material is excreted by the fleshy mantle around the edge of this opening. As the door gets bigger, the shell wraps around itself as a twisted, ever-widening tube. What you see in the cross section is a ‘crib’ that starts off tiny when the snail is just a wee one, and gets larger with age. While not ostentatious enough to make it on MTV, it’s still a cozy and versatile home.

Cute as a Button
A peek inside the Commercial Topshell (Tectus niloticus, Trochidae) shows a low, tightly-twisting whorl, making the whole shell as a compact stout cone. The thick internal walls also provide strong structural support. Such a shape offers good architectural resistance from strong waves in shallow shores, and from shell-crunching fishes & crabs. From larger specimens, round shell disks are drilled to make buttons, hence the name Commercial Topshell, not that it is especially good at banking or international commerce. Since only a few buttons can be drilled from each shell, this species is heavily collected in the Indo-Pacific region where it lives, and since its meat is delicious, it has been fished-out in much of its range. Several countries are developing captive-breeding facilities to raise them commercially, and other programs employ captive hatcheries that release the young back in the wild to supplement the natural population. In many areas though, the main way to promote the population of the Commercial Topshell is to kill off their wild predators, like porcupine fishes, wrasse, bat rays, and crabs. Not such an ecologically sound approach especially since a single darned coconut can make more buttons than a dozen shells.

Home Security
Next we burst into the home of the Strawberry Conch (Strombus luhuanus: Strombidae), one of the smallest but most abundant conch species in the Indo-Pacific. Here we see the shell growing tightly around most of the body, leaving very little of the spire exposed. The aperture of the shell is very long and narrow, but since the resident snail has no internal hard parts, it can flatten its foot, head, and mantle to squeeze through that skinny opening. Such a thin front door is an adaptation against large predatory crabs, nature’s home-invasion robbers. In shells with a larger openings, crabs don’t politely knock, but hold the shell tight with one claw, and with the other, they jab it into the aperture and break the opening away. As the snail withdraws deeper into the shell, the crab just keeps turning and breaking the whorl of the shell until it reaches its prey. With the Strawberry Conch, their security system consists of this narrow opening that prevents a crab from inserting its claw in the first place, and the thickened lip around this opening provides extra strength to prevent the initial breakage of the aperture, keeping the snail safe inside

House of a Hundred Rooms
In this, our last visit through the dwellings of mollusks, we visit the palatial estate of the Chambered Nautilus (Nautilus pompilus; Nautilidae), with a grand array of ever diminishing luminous pearlescent back-rooms. As we saw during our tour through the rather Spartan dwellings of gastropods, the living chamber for the snail is a continuous tube that spirals around an axis, increasing in length and diameter as the animal grows. While the Chambered Nautilus develops in a somewhat similar way, the living chamber holds the mass of the tentacled landlord, but as the shell grows, the previous back-end of the living chamber is walled-off with a shiny layer of nacre. These rooms are connected by a spiral tube, the siphuncle (use that term in your next Scrabble match) that balances fluids, salts, and gasses, ultimately making each empty room an internal flotation device. Gastropods slowly drag their home along the sea floor like low-class campers, but the Chambered Nautilus uses blasts of water from its siphon to push the shell through the open water like a sporty, speedy, jet-powered blimp. In deeper water, the wall between each chamber strengthens the shell, preventing a disastrous implosion. Chambered Nautilus, I like your style.

The post Malacology Monthly: Inside-Out first appeared on Deep Sea News.

Like seashells but are sick of social media?  Hate Facebook but need a hearty dose of marine invertebrates?  Want a bigger malacological meal rather than tiny tidbits of mollusk-based science? Do not worry, you can get all of the “Malacology Monday” posts from the Deep Sea News Facebook page right here on the official DSN website in a tidy & convenient monthly digest without submitting to The F-Book. Here’s what happened last month:

Malacology Monday starts big, really big.
Syrinx auranus, alternately the Australian Trumpet, the Golden Trumpet, and the False Trumpet is the world’s largest living shelled gastropod. This snail is rumored to reach lengths of up to a meter long, but research by members of Deep Sea News can only verify the largest as 72.2 cm (2.36 feet). This specimen from Indonesia is merely 58.2 cm, still nearly two feet in length. What does a snail this size eat? These carnivores tackle large polycheate worms that may grow over a meter in length.

Cloth of Gold, Cloth of…Murder!
In a 1972 episode of Hawaii Five-0, this species of marine snail was used as a murder weapon by a grieving father avenging the death of his daughter at the hands of seedy pornographers. While cone shells have a specialized harpoon & hypodermic needle-like apparatus to deliver toxins to kill their prey, most species are relatively harmless to humans. But some cone species, like the Cloth of Gold, or Textile Cone (Conus textile), can potentially deliver a fatally paralyzing dose of conotoxin to a person handling a live one. However, death can be quite slow, unlike the near-instantaneous demise depicted by those lowlife criminal scum. But not wanting to get nabbed by McGarrett, the mollusk-wielding murderer then turns the venomous gastropod on himself, and the scene fades, with his lifeless body sinking below the placid Oahu waters. Cue the 5-0 theme music…

Bulbous Bling
The Golden Cowrie (Lyncina aurantium) once adorned the kings of Melanesia, and were used as status symbols and units of trade. Their simple beauty and apparent rarity later made them highly sought by museums and private collectors alike, with the shells fetching hundreds of dollars each. It was their cryptic nature and inaccessibility that kept this species safe for a while. Once it was discovered that they were nocturnal, and inhabited the deeper outer reefs from 30-40 meters, they became targeted for the international shell trade. In in some areas, especially smaller islands in the Philippines, specialized Golden Cowrie divers collected them by the hundreds, driving their prices down yet causing local populations of Golden Cowries to plummet. Conservation and management plans are being considered in some areas of the southwest Pacific and Indian Ocean range, but so little is known about their biology that current management plans may not be effective.

Ceremonial Conch
The rather unremarkable looking shell below is actually quite remarkable in two ways. The incredibly thick shell of the Eastern Pacific Giant Conch (Lobatus galeatus) makes it one of the heaviest marine gastropods for its size. But this particular specimen had its spire cut off and made into a pututo, a ceremonial trumpet, and was found in a burial chamber of a lower class member of the Chimu culture of the north-central coast of Peru, about 1300 A.D. Higher-class people often had ornately-carved shells, sometimes with inlays of gems, as part of their burial offerings. The Giant Conch on the right from the Brooklyn Museum is from the older Chavin culture of Peru (about 300 BC) and shows a carving of a man blowing a conch as part of a ceremonial ritual.
All photos, unless otherwise noted, are by Douglas J. Long/Deep Sea News.

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

You already know that Deep Sea News provides expert reporting, in-depth analysis, first-person research, and sarcastic mockery of contemporary topics relevant to our ocean world. Unlike other popular science sites that can be wildly imaginative and dangerously inaccurate, DSN’s crew of scientists cut through the pop-science b.s. and re-posted misinformation to deliver ocean news that you can trust.

But did you know the DSN Facebook site provides even more delicious science nuggets each week for your inquiring mind to chew and savor? Beginning this week, as a premium for our Facebook friends, each and every Monday from now until eternity* will feature the shell of a different marine marine organism in an ongoing DSN internet event called Malacology Monday.

Dipping into the vast marine science collection from the Lobos Marinos International Marine Science (& Cocktails), we will bring you the dazzling array of evolutionary innovations, complex architecture, and endless aesthetics that sea shells deliver. For each species featured we will also communicate bona-fide scientific information and curious facts about the ecology and adaptations of extant and extinct mollusks, as well as the long human history with marine shellfish and their impact on our own culture.

If you like mollusks, and in particular malacology, this is a much-need intravenous drip of taxonomic enlightenment and morphological bliss, and if you aren’t yet in the cult, Malacology Monday will be the digital gateway drug to a soul fulfilling and mind expanding appreciation of our underwater world. So start each week with a stiff shot of mollusks on Deep Sea News’ Facebook Page.

*Eternity not exclusive of time away for expeditions, conferences, vacation, last-minute pre-deadline grant-writing, finals week grading, benders, mandatory time at the honor rancho, amnesia, malaise, or the untimely demise of the concept’s host.

Related articles

The post Malacology Monday first appeared on Deep Sea News.

The first study deals with planktonic forams, single-celled critters responsible for 20-50% of total ocean carbonate flux.  Yeah they are important.  Looking at shell weights of Globigerina bulloides from the Southern Oceans from both today and the Holocene (~10,000), the team finds that weights have declined by 30-35%.  For perspective think of how much you would weigh, if you lost 35% of your weight.  Hell I’d be an underwear model!  The team also correlates low shell weights with 50,000 year long record from a Southern Ocean core.

The second study uses a natural contrast in acidity in the deep sea. In the northwest Eifuku volcano in the Mariana arc the pH ranges from 5.36 to 7.29.  In the common vent mussel, Bathymodiolus brevior, shell thickness and daily growth increments in shells from this area are half those from mussels living in water pH>7.8.  The author suggest that the presence of 40 year old mussels only occurs because crabs are absent from the area sampled.  Crabs agree, “Thin shelled vent mussels, Om nom nom nom.”

Orr, J., Fabry, V., Aumont, O., Bopp, L., Doney, S., Feely, R., Gnanadesikan, A., Gruber, N., Ishida, A., Joos, F., Key, R., Lindsay, K., Maier-Reimer, E., Matear, R., Monfray, P., Mouchet, A., Najjar, R., Plattner, G., Rodgers, K., Sabine, C., Sarmiento, J., Schlitzer, R., Slater, R., Totterdell, I., Weirig, M., Yamanaka, Y., & Yool, A. (2005). Anthropogenic ocean acidification over the twenty-first century and its impact on calcifying organisms Nature, 437 (7059), 681-686 DOI: 10.1038/nature04095

Tunnicliffe, V., Davies, K., Butterfield, D., Embley, R., Rose, J., & Chadwick Jr, W. (2009). Survival of mussels in extremely acidic waters on a submarine volcano Nature Geoscience DOI: 10.1038/ngeo500

Moy, A., Howard, W., Bray, S., & Trull, T. (2009). Reduced calcification in modern Southern Ocean planktonic foraminifera Nature Geoscience, 2 (4), 276-280 DOI: 10.1038/ngeo460

The post Ocean Acidification, Not Good For Living first appeared on Deep Sea News.