You are currently browsing the tag archive for the ‘gastropod’ tag.

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OK, some days, after a long day at work, I am a bit uninspired, but you know who never runs out of endless inventiveness? Nature!  So today, as a run up for next week’s Halloween week of creepy art, here is a gallery of natural expressionism—nudibranch mollusks—some of the most vibrant and exquisitely colored animals in all of the world (you can look at an earlier Ferrebeekeeper gallery of nudibranchs here).

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Now poisonous strange sea slugs are pretty creepy and seasonally appropriate, but to keep this filler post truly Halloween appropriate I have selected all orange, and black, or orange & black slugs (with maybe a fab or purple and white and green here and there).  Behold the glory:

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Aren’t they beautiful! Sometimes I wish I was a toxic gastropod that looked like Liberace and lived in a tropical sea…but alas, like so many of nature’s greatest works, they are vanishing as the oceans change.

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This is Danilia octaviana, a tiny marine gastropod of the family Chilodontidae (the mollusk family Chilontidae—because of a taxonomic mishap, there is apparently a fish family of the same name). Danilia octaviana throughout the Mediterranean Sea (and in the Atlantic near the mouth of the Mediterranean). It is a tiny snail. Adults measure between 7 and 11 millimeters (about a third of an inch). It scrapes up algae and microscopic plants and bacteria with its radula, and is in turn eaten by numerous predators of all different stamps. There is nothing remarkable about Danilia octaviana: there are thousands of small snails like it which live at the margin of our attention (although that perhaps is remarkable, in its own way).  Based on information on the internet, is a bit unclear whether the snail is currently alive or not (the photo above makes it seem like it is a fossil, but some sources speak about it today). I post it here because I think it is surprisingly beautiful and interesting as a textured sculptural whirl.

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A Giant Triton (Charonia tritonis) on an Indonesian Reef

A Giant Triton (Charonia tritonis) on an Indonesian Reef

Yesterday this blog took us to the depths of space to explore the frozen ice-moon of Triton.  Today we atone for that cold voyage with a trip to the inviting tropical seas of the Indo-Pacific.  In these vibrant waters can be found one of the greatest living gastropods, a prince among predatory sea snails, the mighty Charonia tritonis, (commonly known as the giant triton or Triton’s trumpet).

A Giant Triton climbs over a pillow coral in Hawaii

A Giant Triton climbs over a pillow coral in Hawaii

Charonia tritonis grows to over half a meter (20 inches) in length: it is one of the largest living snails in the world (and it is not much smaller than the biggest extant snails). Equipped with a powerful muscular foot, acute senses (particularly smell), and an agile tentacle-like proboscis, the snails are formidable hunters.  Additionally they are protected from predators—even big fierce ones–by their beautiful spiral shells which are vibrantly colored orange, brown, yellow, and cream.  Of course such a shell would become a liability for the snail if an animal ever evolved which killed the snails in order to harvest the magnificent shells solely for their beauty (but what are the chances of that?).

A man sounds a blast on a triton shell--which has spiritual significance in Hawaii

A man sounds a blast on a triton shell–which has spiritual significance in Hawaii

Giant tritons hunt at night.  Their main prey are echinoderms—starfish, which can be large powerful and armored.  Fortunately the snails are not just equipped with powerful muscles and superior brains.  They also have salivary glands that produce sulfuric acid AND a chemical which paralyzes starfish.  The tritons find starfish—even big spiny poisonous starfish like the invasive and all-consuming crown-of-thorns which bedevils the reefs of the Indo-Pacific—then hold them down and inject saliva into them.  As the starfish dissolves from within, the snails rip them apart and feast!

A triton kills a crown of thorns

A triton kills a crown of thorns

Tritons have a specific gender—they are male or female.  They seek each other out for courtship and the female then lays a large clutch of eggs.  When the eggs hatch, the young snails become part of the oceanic plankton for a (poorly understood) time before developing into adults.  Triton shells are esteemed by many cultures as sacred musical instruments.  The shells themselves are collector’s items and are arguably better known then the formidable long-lived predators which make them.  Although the snails are not threatened with extinction as such, there are fewer and fewer really big adult ones (or even small ones) on today’s reefs. This is a real shame, since those same reefs are being devoured by the horrible crown-of-thorns. Hopefully a new generation of divers and wildlife enthusiasts will appreciate the triton on the reef and leave them to their invaluable hunting.  Resist the urge to buy the beautiful shells and help save the reefs of the Indo Pacific!

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Melo Pearl

Melo Pearl

The world’s rarest and most precious pearls do not come from oysters, but instead from very large sea snails of the species Melo melo.  Melo melo snails lives in the tropical waters of southeast Asia and range from Burma down around Malysia and up into the Philippines.  The snails are huge marine gastropods which live by hunting other smaller snails along the shallow underwater coasts of the warm Southeast Asia seas.

Melo melo snail (Melo melo)

Melo melo snail (Melo melo)

Melo melo is a very lovely snail with a smooth oval shell of orange and cream and with zebra stripes on its soft body.  The shell lacks an operculum (the little lid which some snails use to shut their shells) and has a round apex as opposed to the more normal spiral spike. This gives the Melo melo snail’s shell a very aerodynamic lozenge-like appearance (although living specimens look more like alien battlecraft thanks to the large striped feet and funnels).  The animals grow to be from 15 to 35 centimeters in length (6 inches to a foot) although larger specimens have been reported.  The shell is known locally as the bailer shell because fishermen use the shells to bail out their canoes and small boats.

Melo melo at Birmingham's National Sea Life Centre (with keeper)

Melo melo at Birmingham’s National Sea Life Centre (with keeper)

Melo pearls form only rarely on the snails and are due to irritating circumstances unknown to science.  No cultivation mechanism exists (which explains the astronomically high prices).  A single large melo pearl can sell for hundreds of thousands of dollars or more in Asia.  The pearls are usually egg-shaped or oval (although perfectly round specimens are known) and they can measure up to 20-30mm in diameter.  Not nacreous (like pearls from oysters & abalones), these valuable objects have a porcelain-like transparent shine.  Melo pearls are brown, cream, flesh, and orange (with the brighter orange colors being most valuable).

Melo pearls with Melo melo shell

Melo pearls with Melo melo shell

Apart from the fact that they come from a large orange predatory sea snail, what I like most about melo pearls is the extent to which they evoke the celestial.  It is hard not to look at the shining ovals and orbs without thinking of the sun, Mars, Makemake, and Haumea.  Rich jewelry aficionados of East Asia, India, and the Gulf states must agree with me.  It is difficult to conceive of paying the price of a nice house for a calcium carbon sphere from an irritated/diseased snail, unless such pearl spoke of unearthly beauty and transcendent longing.

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A Black Smoker Geothermal Vent

A Black Smoker Geothermal Vent

The African Plate and the Indo-Australian Plate meet together deep beneath the surface of the Indian Ocean in a long line of tectonic divergence known as the Central Indian Ridge (CIR).  As new seafloor is created hydrothermal vents pour out molten hot fluids rich with minerals and an alien landscape is formed.  The hot minerals precipitate to form high cylindrical chimneys called smokers and strange communities of life form along these structures.  This ecosystem is entirely based upon chemosynthetic archaea (ancient one-celled life forms which take energy directly from the oxidation of inorganic compounds).  Great communities of eyeless shrimp, giant tubeworms, and annelids support themselves on the archaea.  Among the strange creatures is a very weird gastropod mollusk, the scaly-foot snail (Crysomallon squamiferum), which is different from every other mollusk (and indeed every other animal) because of the material it uses for its bizarre scale-mail armor.

The Scaly Foot Gastropod (Crysomallon squamiferum)

The Scaly Foot Gastropod (Crysomallon squamiferum)

The scaly foot gastropod has an armored foot which is covered in little scales made of iron sulfides.  Additionally the deep-sea snail has a triple layer shell.  The outermost shell layer is composed of iron sulfides, the middle is a thick protein coat, and the inner shell layer is composed of aragonite (a calcium carbonate).

I wish I could tell you more about the habits of this snail but since it is found in super heated water at the bottom of the Indian Ocean, it has not been extensively studied.  However, The US military is interested in the creature as a possible inspiration for next generation composite military armor so maybe we will all learn more about the scaly foot snail.

Detail of the Foot Armor of Crysomallon squamiferum

Detail of the Foot Armor of Crysomallon squamiferum

Marbled cone snail (Conus marmoreus) by shadowshador

In olden days, in Australia, young healthy beachgoers were sometimes found lying on the shore dead.  Their bodies gave no evidence of trauma, indeed they had not even gone into the water. Something just struck them down as they sauntered along the beach.  It was not until 1936 that the mysterious killer was finally revealed when a beachcomber picked up a colorful snail and began to scrape its shell with his knife.  The unlucky young man uttered a cry as the snail somehow pricked him.  He then fell down, went into a coma, and shortly died.  Because of witness testimony, coroners knew what to look for and they removed a tiny poisonous harpoon the size of a small hair from the victim’s hand. The culprit turned out to be a cone snail, one of a diverse group of deadly gastropod mollusks.

The Geographic Cone Snail (Conus geographus) shows its siphon and proboscis. This snail is also humorously called “the cigarette snail” since if one stings you, you allegedly have time for one cigarette before dying.

There are over 600 different species of snail within the genus Conus and they are all poisonous predatory hunters.  The smaller cone snails hunt tiny mollusks and worms but the larger snails feed on fish, which need to be quickly subdued (so that they do not injure the snail by thrashing about) and then consumed with equal dispatch so that other ocean creatures do not steal the meal.  In order to quickly dispatch their prey (and defend against larger predators), Cone snails have a sophisticated weapon–a modified radula tooth which directly injects potent venom by means of a tiny harpoon-like “dart.”  The snail finds prey by carefully testing/sniffing the water with a siphon.  It then stretches out a long flexible proboscis and fires the disposable hollow radula tooth (filled with venom) into the prey by means of a powerful muscle contraction.  Below is a shocking film which shows a cone snail killing and consuming a clown fish by such means.  It is not for the faint of heart!

Although cone snails are obviously alarming to divers and shell collectors (particularly in warm tropical reefs where the large poisonous specimens live), the potent cocktail of neurotoxins utilized by the creatures is of great interest to pharmaceutical researchers.  Since each species of cone snail has a very large number of different “conotoxins” in its poison, scientists have been struggling to catalog and understand the dangerous mixtures. These conotoxins are generally peptides which interfere with the ability of nerve cells to communicate with one another.  Not only might such chemicals provide the key to curing neurodegenerative diseases and brain cancers,  conotoxin research is now the most promising avenue towards effective medications to deal with certain sorts of chronic pain.

A lovely diagram of Conotoxin Peptides from “The Journal of Neuroscience”

Unfortunately all of this research has not provided any effective antitoxins for victims of cone snail stings.  If a person is fully darted by one of the large poisonous specimens, their best hope is to go on a ventilator until their body expunges all of the poison—an uncertain prospect at best.

A Tiny Sample of the Exquisite Variety of Cone Snail Shells (Photo by Pet/Wikimedia Commons)

Many cone snails have beautiful colorful shells marked with vivid abstract patterns.  Some of the most valuable shells ever came from cone snails–which continue to fascinate conchologists and shell collectors.  Even today divers and beach combers are sometimes overwhelmed by the beauty of cone snails and reach out to grab the lovely creatures.  Hopefully this article has convinced you that doing so is a very bad idea.

A Conch Used as a Trumpet

Conches are large sea snails.  True conches are from the family Strombidae, but there are a number of other large marine snails which are also colloquially called conches including horse conches (Fasciolariidae), crown conches (Melongenidae), and the “sacred chank” (a member of the Turbinellidae family).  These powerful marine snails are fascinating organisms in their own right—but today’s post is not about biology, rather it concerns music. When properly prepared, conches can be made into lovely and powerful wind instruments. Such shell trumpets have been found in use by cultures from around the world and specimens have been found dating back to the Neolithic era (although the musical use of shells might predate even that).

3000 year old Strombus galeatus shell modified as a musical instrument by pre-Inca people of Peru

Different cultures obviously use different shells for their trumpets and the instruments also serve varying purposes.  The magnificent big pink queen conch (Lobatus gigas) from the Caribbean was used as a trumpet by the Carib, the Arawak and Taíno peoples.  In India, the shell of the big predatory sea snail, Turbinella pyrum has long been crafted into the shankha, a religious musical instrument emblematic of the Hindu preserver god Vishnu (who last appeared in Ferrebeekeeper slaying the demon of Lake Lonar).  The shankha (also known as the sacred chank in English) can be intricately carved.  Though initially used as a charm to ward off the dangers of ocean travel, it long ago came to be associated with Vishnu worship and with nagas—water serpent deities.  Buddhists from the subcontinent also esteem the same instrument  as one of the eight auspicious symbols of that faith.  The Tibetan Buddhists call such a trumpet a “Tung.”

Vamavarta shankhas, c. 11-12th century

The Triton shell, Charonia tritonis, is used as a wind instrument throughout its Pacific range.  In Polynesia the instrument is called a “pu” whereas in Japan the horn is known as the horagai.  Likewise the Triton’s shell is a military instrument in traditional Korean music (where it is known as a nagak).

A Korean Bugler plays a Nagak

The cultures of the Mediterranean also made extensive use of conch-horns as foghorns and signaling devices and it is through Greek art and literature that conch horns made their way into mainstream Western art of the last two millennia.

Triton blowing on a Conch from the Bailey Fountain in Brooklyn

There seem to be two major ways of crafting a wind instrument from a large gastropod– both of which essentially involve creating an aperture in the whorl of a large gastropod shell. Mitchell Clark summarizes them with admirable clarity in his excellent article about shell-trumpets writing:

 There are two basic places this hole may be placed, and so there are two basic approaches that can be taken for making a conch shell into a shell trumpet. A hole is made either at the apex (the tip of the spire) of the shell, or, alternatively, in one of the whorls to the side of the spire…. In some cases the hole itself forms the mouth hole; in others, a mouthpiece is added.

The sound of such a trumpet is a rich rumbling primal roar—but it is usually only one note in one key.  Although pitch can be modified with finger holes or embouchure, such an approach is unusual.  But enough talk about shell trumpets!  Below is a Youtube video of a um…contest-winner playing one.

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