Lunar eclipse, Christopher Columbus and the Teredo worm. A convergence of astronomy, history and biology.

       Native Americans (such as the Pomo, the Ge, the Serrano and Hupa), the Vikings and the Chinese all have their own myths about the lunar eclipse.  The Vikings believed that the moon is eaten by Hati, the wolf; the ancient Chinese says that the dragon ate the moon; the Serrano Indians thought that the dead spirits did it too.  There are two common themes—that something ate the moon and it takes loud noises to make these things give it up.  For the Chinese, the moon is represented by the mirror and during the lunar eclipse, millions of Chinese beat mirrors to make the dragon give back the moon. 

      My lunar eclipse experience did not involve making a lot of noise, though I can hear my teeth chattering from the cold.  After all it was after midnight in New York City and my neighbors might call the cops on me if I started beating mirrors.  I suppose New Yorkers are not ancient enough yet to develop lunar myths and, if we ever do, it is not likely to involve making loud noises.  Maybe a sudden rush to Starbucks for the new ‘moon latte’ is more like it.  I was among the perhaps 1.5 billion people on Earth that watched the lunar eclipse unfold last Tuesday, December 21, 2010.  I seem to have been the only crazy one in my neighborhood to stay through that 3 hours and 38 minutes outdoor viewing event at 30 oF.  But, I had to see it. 

       Though lunar eclipses are reasonably common, this one is particularly rare because it comes at the precise time of the solstice.  For those like me who are unfamiliar with the term, solstice (from Latin sol meaning ‘sun’ and sistere meaning ‘to stand still’) occurs when the Sun’s apparent position in the sky from an earthbound observer reaches its northernmost or southernmost extremes at which time the movement of the sun comes to a stop before reversing direction towards north or south.  I am sure you are still a bit confused by this explanation, but the story must go on ! 

       I was told that the previous eclipse occurring at the same time as the solstice was in 1638 and the next one won’t come till 2094.  Unless someone discovered Ponce de Leon’s ‘Fountain of Youth” or some scientist finally figure out how to stop aging, I don’t think I will make it to the next moon show.  Even if I did, I will probably be just as happy to be breathing and the last thing I would want is to be outdoors at 30 oF ever again watching the moon turn red. 

       As I was thinking of tropical themes to keep my mind off the morning freeze (for instance–sunset by a tropical beach, sipping margaritas at 85 oF under the coconut tree and attended to by exotic young maidens wearing a sarong), I remembered reading before about Christopher Columbus being marooned on his fourth voyage to the Caribbean, spending a year under coconut trees and warm beach of Jamaica, watching the lunar eclipse too—exactly how I would have wanted it.  His lunar encounter was at least more interesting as you will read later on—so don’t go away.  Finally getting my dose of astronomical adventures for the year, I went back inside to read more about the voyages of Columbus—and that’s because there was nothing good on TV at 4:30 AM for insomniacs like me. 

       So how the voyage of Columbus relates to the eclipse and Teredo worms?  Science and history always converge at some point, often in unpredictable ways, sometimes taking me along for the ride as well.   And, before I tell you about it, I think you need a short course on Teredo first.

The terrible Teredo, termites of the sea

Teredo worms inside an infested wood being collected in Batan, Aklan Province, Philippines. Photos by Coleen P. Sucgang.

       Anything that’s long, slimy and ugly is always termed a worm (as long as it doesn’t bite, which would automatically get the label as a snake) .  However, this doesn’t apply to shipworms, also called by mariners as the ‘termites of the sea.’  Scientifically, they belong to the genus called Teredo, the most notorious of which is Teredo navalis, originally native to the Caribbean Sea.  It is actually a clam, though looking at the pictures here, one would hardly believe that.  But it is!  And the male Teredo is one lucky stud.  There’s 1 Teredo male per 1,500 females.  Must be one very exhausted male and probably don’t live very long.  For the male Teredo, this phrase certainly applies:  “….live fast, die young and leave a beautiful corpse behind.”   Just in case you are curious where it came from, the phrase originated from the 1947 novel by Willard Mothley about juvenile delinquents (turned into a 1949 movie with Humphrey Bogart) entitled “Knock on Any Door” and also often quoted lately to describe rock and movie stars dying young from drug overdose.

       After fertilizing the eggs by the overworked (and maybe overjoyed) male Teredo, the developing eggs are protected inside the female until they develop into free swimming larvae.  Then, the little terrors meander in the high saline sea until they find fresh wood (They don’t like old wood) to settle on, unless

A Teredo worm taken out of the wood and close-up images of the tri-lobed shell and siphons. Photo credit: Coleen P. Sucgang, Poseidon Sciences.

they get eaten first by something else.  Then it starts burrowing through the wood as it grows, parallel to the grain, only turning to avoid any knot on the wood or if there is any obstruction.  By the time it reaches adulthood, it is already at least a foot long and half inch thick.  If you think this is big for a worm, its Sumatran cousin, the Giant Teredo, grows to six feet long, but lives in the muddy bottom of the sea rather than inside wood.  Unlike other typical clams, the shell covers only a tiny portion of the Teredo and used more like a drill bit to burrow a circular hole through the wood.  The tube-like home is capped at the opening of the burrow with a secreted calcareous cover, with protruding siphons that allow the animal to breathe, feed on plankton and excrete wastes.  Inside its burrow, the Teredo‘s color is pinkish white.  When removed out of its home, the color changes to a lighter blue shade in just a few minutes.

The good things about Teredo 

      Before I tell you the bad reputation of shipworms, it is only fair to describe a few good things about them.

Brunel's original design of the tunneling shield (top). A modern tunneling shield

First, the tunneling behavior of the shipworm inspired Marc Brunel, a French engineer, to devise a method, which he patented in 1818, to tunnel under the Thames River in England, the first of its kind ever built under a muddy river bed.   His technique called the “tunneling shield” made use of his observations while working on a shipyard on how the shell with fine ridges were used by the Teredo to drill through the wood while protecting itself from being crushed.  The Teredo also secretes a calcium-rich framework that coated the inside surface of the tunnel, keeping it stable and crush proof. 

Second, the cellulose that makes up the wood is not sufficiently nutritious as food and the shipworm cannot normally digest it.   It overcomes this limitation through a symbiotic relationship with bacteria, Teredinibacter turnerae, in its gills that secrete enzymes, called cellulases and nitrogenases, breaking down the cellulose and fixing nitrogen to build amino acids.  By the way, cellulases are the same enzymes, derived from fungi, used to create your stonewashed denim jeans by breaking down the cellulose on the outer surface of the cloth.  Now, it is also a major ingredient in most laundry detergents to improve cleaning efficiency.  The potential of Teredo-derived cellulases is in its future use in biofuels because it is likely more efficient than fungal cellulases in converting paper-mill cellulose waste into ethanol or methanol.

Third, Teredo worms serve an ecological purpose by degrading the wood materials that end up in the ocean.

Benedetto archtop guitar made from Sitka spruce with Teredo holes. Bottom shows close-up of the guitar with the holes made by Teredo.

Fourth, Teredo-infested Alaskan Sitka spruce used as log floats back in the 1950’s and 60’s, when transformed into a 16” traditional Benedetto archtop guitar, becomes a unique, spectacular and most expensive archtop guitar at the hefty price of US$ 52,000. 

And lastly, Teredo worms make a special Philippine delicacy called tamilok, appreciated only by natives of Palawan Island and Aklan Province in Panay Island.   It is prepared raw as a ceviche or kinilaw in the local language, with vinegar, chili peppers and onions.  Must be a scary delicacy and certainly not for the timid.  Think of your appetizer as a moving, living, half-inch thick spaghetti.  But, then again Teredo’s only known predators, the Palaweňos and the Aklanons, are probably more adventurous epicurian diners than the rest of us.  I had been in both islands, had heard about it, but never did have a chance to sample this squirming dish.  Maybe, I will try tamilok on my next trip down that way.   

Tamilok: Teredo dish.  Delicious, isn’t it?

My affair with Teredo

      One of our long drawn out research project has been to develop a nontoxic repellent against a wide variety of invertebrates.  Many years ago we have successfully developed one, called MR-08 that repels barnacles, mosquitoes, ants, flies, termites and even leeches.  This is a food grade derivative of menthol with a propylene glycol side chain that reduced the menthol smell by 95% and increased the repellent effect many fold.  So confident that it will work against Teredo, I asked our long time research collaborator, Sister Avelin Mary at Sacred Heart Marine Research Centre in India, to find areas with Teredo worms.  We soaked fresh wood with MR-08 until we were confident that it has absorbed all the way into the wood and then immersed them for a few months in Tuticorin Bay in South India.  No luck.  Teredo just ate through that wood samples as if there was nothing there.  So far, it is the only invertebrate organism that seems to have no reaction against our repellent.  

       I just gave up on MR-08 but I have a new idea for an ecofriendly, bioactive natural chemical that will prevent the Teredo from burrowing.  So, just for the moment, Teredo wins the first round! 

Now for the bad news      

       Shipworms have been a bane to ancient mariners until the advent of copper clad ships by the 18th century and modern marine coating on steel hulls.  These boring clams weakened the wooden hulls of ships to the point that they break apart in the open sea without any warning.  The Greeks and the Phoenicians certainly knew about them since 3,000 BC, lathering the hulls of their ships with wax and tar to keep them away.  The Romans used combinations of lead, tar and pitch to cover their boat. 

        Unbeknownst to Columbus, his first voyage to the Caribbean Sea in 1492 exposed his ships to the world’s most Teredo-infested waters, likely due to the higher salinity and higher seawater temperature of the Caribbean.  The ships that arrived later brought back Teredo navalis to Europe, where they can be found even as far away as the North Sea, having adapted to the cold environment.  Hundreds of ships had been lost at sea just because of Teredo worms.  These same worms caused the collapse of the wooden supports used in the dikes of Holland in 1731 causing flooding, 250 years after the first voyage of Columbus.  Only the timely replacement of the outer surfaces of the dike with stones prevented more catastrophes.

        In modern times, we have yet to escape the wrath of the Teredo.  Wharves, piers, jetties and pilings started collapsing in San Francisco Bay between 1919 and 1921, resulting in almost 20 billion dollars worth of damage in today’s money, all because of Teredo.  The mouth of the Hudson River of New Jersey and New York was once considered a ‘dead’ waterway, devoid of fish life because of the overwhelming industrial pollution since the 1930’s.  Ship captains used to sail their boats through NY harbor just to kill off shipworms and barnacles.  That’s how polluted it was.  In 1972, the US Federal Clean Water Act limited discharge into the rivers and proactively revitalized the waterways.  By the 1990’s fish had returned.  And so did the Teredo, with a vengeance.  During this period also saw the voluntary ban by the lumber industry on the use of creosote and CCA (chromated copper arsenate) to prevent further leaching of the toxic chromium and arsenic to the environment.  These wood preservatives prevented fungi from rotting the wood away and also quite good at killing off termites and shipworms as well.  These good deeds had unintended consequences—piers and piling along the Hudson River that no longer used preservatives started collapsing, hollowed through by Teredo worms.

Christopher Columbus

       After discovering the New World by accident in 1492 (He was trying to reach India and China by going across the Atlantic), Columbus had undertaken three more voyages back to the Americas, mostly in search of riches in gold and silver to recover the cost of the previous voyages.  But the Caribbean was not particularly rich in anything but warlike Caribs and Arawaks.  Though forbidden by Queen Isabela of Spain to get involved in slave trading, financial pressures from investors forced Columbus to disobey. On his second voyage, he obtained 1,200 Arawak natives captured by the Carib tribe and transported 560 of them to Spain, 200 of whom died en route.  Though the Spanish monarchs at the time disapproved of slavery, 200 of these natives were used as galley slaves nonetheless while the rest were returned back to their native lands.  Though not widely known, Columbus’ second claim to fame is to start the slave trade in the New World. 

       In the province of Cicao in Hispaniola (now Haiti and Santo Domingo), to fulfill his promise to investors to fill his ship with gold, Columbus instituted a tribute system whereby each native above 14 years of age must pay in gold every 3 months. In return each received a copper token to be worn as a necklace (not quite a fair deal).  Anyone caught without a copper token was punished by having their hands cut off.  Though it failed to yield the riches he expected, that started the gold rush (his third accomplishment, if one can call it that) to the New World that destroyed the civilizations of the Incas, the Aztecs and the many other indigenous tribes in the Americas.

        His fourth voyage was not particularly successful either.  He went to Panama upon learning from the natives about more gold to be had and a strait connecting to another ocean.  One of his ships was stranded in the river called Rio Belen and by the end of his voyage the garrison he built there was attacked; more ships damaged.  More bad luck came on his way to Hispaniola in 1503 when a storm damaged his remaining flotilla and the hulls almost breached because of the Teredo worms that infested the wood.   Most certainly, the ships would have broken apart had he went further.  No choice but to beach his vessels in St. Ann’s Bay in Jamaica.  Waiting for relief ships to come to his rescue, Columbus and his sailors had to rely on food and help from the natives who were momentarily awed by the presence of the new arrivals.  As months go by, the natives got weary of the Columbus and his men.  Angered by the occasional thievery and bad behavior of the sailors, the natives began refusing to send food to the point where his sailors wanted to invade the villages to take what they needed by force.

Map showing the four voyages of Christopher Columbus (top). Print with Columbus showing the natives that God is taking their moon away (bottom).

        Columbus thought of a better way and summoned the village chiefs for a talk at sunset on February 29, 1504.  Opening the discussion with the announcement that God was not pleased with the way the people were treating the sailors and that God would show his disapproval by taking the moon away were met with disbelief and laughter by the chiefs.    No one controlled the sky as far as the natives were concerned.  As the moon rose up in night sky, the bright full moon dimmed, lost half of its light. This loss of light continued until the moon dimmed completely, turning to amber color.  The natives began to wail, begging Columbus to beseech the Almighty to return the moon.  Frightened by the display of this ultimate celestial power, they promised to bring food once again to the sailors in return for forgiveness and giving the moon back to them.

       Columbus told the chiefs that he would consult with the Almighty in his hut for a while to see if God is in a forgiving mood, likely just checking his hour glass and waiting for the right moment.  Then Columbus returned after 48 minutes to declare that God had forgiven them and was returning the moon again.  And God promptly did.  Soon after his declaration, the lunar totality was completed and the bright moon reappeared once again.  The lunar eclipse saved Columbus and his men from starvation and saved the villagers from rampage by the sailors.

       How did Columbus know about the lunar eclipse?  He kept a copy of the Ephemeris by the great German astronomer, Regiomontanus, with him on his voyages. 

Regiomontanus and a page from the Ephemeris

      The Ephemeris (from the Greek ephemerios  meaning ‘daily’) is similar to what we consider now as the almanac.  Johannes Müller von Königsberg (6 June 1436 – 6 July 1476), more widely known by his Latin name Regiomontanus (It was fashionable at the time for famous scholars to adopt Latin names), was a mathematician, an astronomer, translator of Ptolemy’s writing and famous for his astronomical tables and instruments (sundials, astrolabes) in the 15th century.  A precocious boy, he went to the university in Leipzig at age of 11 and received his degree of ‘magister artium’ (Master of Arts) at 21 in Vienna in 1457.  His astronomical and mathematical works were the best of his time and his Ephemeris considered one of the first applications of mechanical computers.  A moon crater is even named after Regiomontanus.

        The Ephemeris was a printed table of values that gives positions of the objects in the sky at any given time using a spherical polar coordinate system of right ascension and declination.  Regiomontanus went to Vienna in 1475, a year before his death, to help Pope Sixtus IV to reform the calendar and along the way managed to finally print his Ephemeris, a copy of which was carried by Columbus two decades later on his voyages.

This story is truly a convergence of many unrelated events:

  • Teredo worms destroying Columbus’ ships
  • The total lunar eclipse happening while Columbus was stranded and his trouble with the natives
  • Regiomontanus publishing the Ephemeris and Columbus having a copy with him on his voyages.

The voyages of Columbus were full of accidental discoveries and his survival on that last voyage showed that, despite his misfortunes as a ‘get-rich quick’ fellow, he was still a one very lucky seaman in the end.

        And, the Teredo still reign as the world’s best little terror of the high seas.  Who knows, 200 years from now the Teredo may even evolve to burrow through plastics, paint and steel.  Then, we will be in real trouble!

Jonathan R. Matias, Chief Science Officer

Poseidon Sciences Group

www.poseidonsciences.com

Suggested Reading:

For interesting stories about the Teredo, please read the articles by Jerilee Wei and Kristin Cobb below:

Jerilee Wei. Teredo. The terrible shipworm that eats wood. http://hubpages.com/hub/Teredo-The-Terrible-Shipworm

Kristin Cobb, Science News, Aug. 3, 2002.  Castaway: the gripping story of a boring clam – shipworm.  http://findarticles.com/p/articles/mi_m1200/is_5_162/ai_90468391/?tag=content;col1

http://www.poseidonsciences.com/MR08_nontoxic_repellent_menthol_mosquitoes_flies_termites.pdf

http://en.wikipedia.org/wiki/Shipworm

http://en.wikipedia.org/wiki/Regiomontanus

http://en.wikipedia.org/wiki/Ephemeris

http://www.1911encyclopedia.org/Teredo

http://www.frammandearter.se/0/2english/pdf/Teredo_navalis.pdf

http://benedettoguitars.com/boutique/il-teredo/

Rip Van Winkle, Hibernating Fish and Malaria Control

Annual killifish male and embryos in peat

When I think of hibernation, my first thought is my high school English literature class on Washington Irving’s tale of a Dutch settler named Rip Van Winkle.  The story’s setting is New York’s Catskills Mountains during the American Revolutionary period.  In this tale, Rip Van Winkle was a fun-loving, lazy, henpecked husband who escaped his nagging wife by running to the mountains where he encountered strange men playing nine pins.  After drinking their liquor, he fell asleep under a shady tree.  Rip returned to his village after waking up only to find out that 20 years had passed and America was a already a new republic.  Many of us would wish we can do just that when times are rough and wake up later when times are better.

Irving’s story of Rip Van Winkle was likely influenced by ancient folklores in Orkney (Scotland) where a drunken fiddler find trolls having a party, plays music with them for two hours and goes home  to find that 50 years had passed.  But there are even more older tales of a similar nature around the world, such as the German folktale of Peter Klaus, of Niamh and Oisin in Ireland, the ancient Jewish tale of Honi M’agel, the Chinese story of Ranka in 3rd century AD, the 8th century Japanese tale of Urashima Taro and the story of the Seven Sages by Diogenes Laertius of the 3rd century.  The Seven Sleepers of Ephesus tells of Christians escaping Roman persecution by sleeping in a cave to awaken after a century to a new world wherein Christianity became the new religion of the Roman Empire. 

As there are numerous variations of the hibernation theme in the literature, there are even more variations of hibernation in the natural world.  Insects do it all the time; as do seeds of plants.  Tiny invertebrates, like the tardigrade, remain in hibernation for over a hundred years in a dry state and ‘reawaken’ when exposed to water.  As long as it is hibernating, the tardigrade can withstand extremes of pressure, temperature, desiccation and low oxygen.  Artemia cysts, commonly known as brine shrimp eggs that hobbyists hatch to feed fish fry, behave like that too.  They remain hibernating in a dry state and re-animate when placed in salt water, becoming the “sea monkeys” that most of us remember as a child.   Other mammals do it too.  Female kangaroos, bears and badgers can delay the implantation of the embryo by inducing reversible developmental arrest to postpone the period of birthing until months later when food is plentiful.  Just like Rip Van Winkle, these animals escape inhospitable conditions by escaping in time.

Diapause (from the Greek dia meaning between and pauein meaning to stop), suspended animation, aestivation, hibernation and crytobiosis (hidden life) are terms that evoke images of a long, but temporary sleep.  For most organisms that are unable to physically move away, it is their only means of surviving harsh environmental conditions until the next more favorable season.  Even now, the science of suspended animation is advancing far beyond insects and arthropods.  Non-injurious suspended animation can be induced in mice for a short time by replacing the oxygen in the air it breathes with hydrogen sulfide.  The long term medical potential in human terms is delaying trauma from injury until more favorable medical interventions can be applied.

Where does fish come into this?  First, let me tell you a story of my own fascination with one unusual class of tropical fish that do exactly the same.  They are called annual killifish (from the Dutch word kill meaning small stream). They thrive only in seasonal pools that evaporate totally during the dry season.  When the rains come the following year, or even five years later, the fish population returns again to re-populate the pond.  They are not the lungfish that most of us might be familiar with.  Lungfish ‘aestivate’ in mud chambers they create before the pond dries up.  They continue breathing air through a hole on top of the moist chamber while at the same time reducing their metabolism.  Annual fish are unique because they can completely stop at three specific diapause stages of their normal embryonic development.  They escape in time by near zero metabolism and complete cessation of embryonic development.  Though not as extremophile as the tardigrade, the diapause stages of the annual killifish are more resistant than non-diapause stages to extreme conditions in their environment

My first introduction to this fish was during the 1970’s in the laboratory of Jules Markofsky, who at the time was studying the annual killifish, Nothobranchius guentheri, for aging research at the Orentreich Foundation.  Annual killifish live for about one year.  Some species even have life spans as short as 4 months.  Compare that to the guppy that can live as long as five years and the mouse or rat for about 4 years.  Back then, so little is known about the biology of the killifish that we were unable to get enough embryos to hatch synchronously to do aging research. In fact, we sought help from the Long Island Killifish Association, an esoteric and dedicated group of hobbyists that maintain such rare fish in captivity.  It was such a fascinating group that I, too, joined the Club.

Fish hobbyists know more about these unique and colorful killifish.  And, there are dozens of such specialized clubs in US and Europe.  In fact, one does not need to go to the jungle to find most of these species.  Just meet with any one of the killifish hobbyists who can share some diapause eggs.  Hobbyists continue to brave malarial mosquitoes and wild animals, even animals of the two-legged kind, to bring back live specimens from Africa and South America that are then bred in aquarium tanks.  While environmental degradation and man-made land alterations likely have doomed scores of native populations, much of the species known today exist in the aquarium hobby.

After 25 years studying diapause in N. guentheri, combined with the work of other scientists/ hobbyists, I began to have a better idea of the environmental cues that trigger the onset and termination of diapause.  The day-night cycle, temperature, humidity and maternal cues that influence the development of diapausing states in silkworm, for example, are the same in killifish—an unique example of convergent evolution. 

How about malaria?  Curiously, the geographic range of malarial mosquitoes and annual killifish in Africa and South America overlap.  George Myers, a noted ichthyologist of his time, in the 1950’s first observed reduced incidence of mosquito bites in areas populated by killifish.  Since then Richard Haas, Rudd Wildekamp, Jules Markofsky and I have proposed at various times in the last 30 years to use this fish for mosquito control.  Since most countries have a few native species of annual killifish, we can even keep the environmentalists happy since we don’t need to introduce any exotic fish to do this.  The local ones will do just as well.  All we need is to grow and distribute a lot of them around. 

The tribesmen in the sub-Sahara Africa already use annual killifish in freshwater storage containers and wells.  Hobbyists already know that ‘killies’ are larvivorous.  Yet, common anecdotal knowledge is not enough to push regulators and funding agencies to use this fish for mosquito control.  Recently, the publication in the online journal Parasites & Vectors finally verified the anecdotal evidence by methodically demonstrating the feasibility of using killifish as mosquito control agents.  In this paper, the embryos in the pre-hatching hibernating state were transported in moist peat moss and dropped in temporary ponds where they hatched, consuming all the mosquito larvae.

Although conventional larvivorous fishes have been used to rid mosquitoes in ponds as far back as the building of the Panama Canal, their use had been limited to more permanent waters.  Fish predators, like Gambusia, work great on abandoned swimming pools after hurricanes, for example.  But this fish has wrought havoc in many ecosystems because of their prolific and voracious nature.  Transporting even native conventional live fish to remote areas is a big hassle.  With only dirt roads and footpaths available to reach rain pools, mining pits and similar transient pools, transport by water trucks is just not practical. 

Now we have a transportable fish in a bag.  Instead of a water truck, a backpack is enough to carry a million diapausing killifish eggs!  Sort of like Johnny Appleseed, another American legend, bringing bags of eggs instead of bags of apple seeds. 

The idea of the ‘instant fish’ is nothing new.  It’s been tried unsuccessfully a few times as a business.  What’s new is taking this technology to a more useful purpose.

How can we transform this idea of “instant fish in a backpack” into something practical for malaria control in the future?  Stay tuned to my next blog when I get re-animated again.

— Jonathan R. Matias

Suggested reading:

Annual fish biology

http://www.poseidonsciences.com/annualfish.html

http://www.aka.org/

mosquito control

http://www.parasitesandvectors.com/content/3/1/46