The Crown-of-Thorns Starfish

Clouds of reef fish and corals at Papahānaumokuākea Marine National Monument.

I know I just did a post on National Donut Day, but that piece was both tongue-and-cheek and nakedly self-interested.  Clearly donuts are ephemera with transient importance—scraps of fried dough which stay tasty for less time than flowers bloom (indeed I enjoy juxtaposing their cheap impermanence with the vast seemingly eternal universe in my paintings).  Today I looked at my calendar to find that June 8^th is World Oceans Day!  Unlike National Donut Day (which is self-evidently a meretricious marketing “holiday”), World Oceans Day strikes me as an important and worthwhile day of observance.  The ancients celebrated the oceans with festivals and sacrifices to venerate the sea gods.  We tend to regard the oceans as an inexhaustible source of cheap fish and a place to dump our rubbish.  I worry that the careless industrialized spoiliation of the oceans is the gravest mistake humankind is currently making (and we have our grubby grasping fingers in lots and lots of pies—and are making plenty of errors).  Yet, I don’t want this blog to become an angry jeremiad or an environmentalist harangue.  I want to celebrate the beauty and grace of the oceans and their inhabitants while also underlining the stress and danger which these vast swaths of the world are facing.  What to do?

An infestation of Crown-of-Thorns Starfish

For World Ocean Day therefore I am writing about the lifeform which, to me, most exemplifies the oceans of the late Holocene/early Anthropocene, the crown-of-thorns starfish, Acanthaster planci. This echinoderm is a ravenous poisonous destroyer which is exploiting the sickness of the oceans to proliferate and succeed wildly (at the expense of everything else).  It is an amoral ravenous monster covered with toxic spines which is eating the coral seas bare.  It is also a beautiful creature magnificently evolved to thrive—we can hardly hold its horrifying success against it.  Maybe it should be on the cover of Forbes smoking a cigar and bloviating about its philosophy of success.  By chance the starfish also lies at an intersection of many blog topics—crowns, invaders, colors, poison, mollusks (for its fate is connected with that of predatory mollusks), opinion, and science…perhaps even “deities of the underworld”.  This is a lot of introduction…let’s meet our antihero!

Crown of Thorns (Acanthaster planci) photo by jon hanson

The crown-of-thorns starfish (or “sea star”), Acanthaster planci takes the form of a spiked disk with up to 21 prehensile arms (also covered in spines). On its underside, the starfish has numerous sticky tube-like suction feet running along the bottom of each arm. These legs run in parallel rows beside a series of closely fitting plates which form a central groove on the bottom of each arm.  The arm grooves each run ominously into the starfish’s horrifying stomach/mouth.  The starfish can grow to a diameter of up to 80 centimeters (31 inches) although they are more commonly found in the 35 centimeter range.  Acanthaster planci has a wide Indo Pacific range and lives in tropical and semitropical coastal waters from the Red Sea and the East Coast of Africa across both the Indian and Pacific Oceans all the way to the West Coast of Central America.  The starfish are usually dull grays and reds but they can range to brilliant purple, blue, orange, aqua (or display all sorts of mixed ranges). Their colors are highly mutable and variable! These starfish eat coral polyps!  It crawls into corals by means of its many sucker feet—compressing or elongating its body as needed.  When in position the starfish extrudes its stomach over the polyps it wishes to eat: the stomach can cover an area approximately equal to the starfish.  The creature then releases digestive compounds which dissolve the soft parts of the coral into a soup which the starfish slurps up.  It then retracts its stomach and moves on, leaving a bleached (i.e. dead) patch of coral skeleton.  A medium sized starfish can consume up to 6 square meters (65 sq ft) of living coral reef per year.  If times are lean the starfish can go for months (or longer) without eating. http://www.arkive.org/crown-of-thorns-starfish/acanthaster-planci/video-00.html Crown-of-thorns starfish are male or female and they do not reproduce by budding, but female starfish lay from 6.5 million to 14 million eggs each per breeding season [hereupon the author wiped his furrowed brow].  When the eggs hatch there are several interesting larval stages which the echinoderm goes through before reaching their adult form.  Suffice to say, the starfish reaches sexual maturity after 2 years and it lives as long as 8 years. Fourteen million offspring per season is a lot!  If predators do not keep the crow-of-thorns starfish in check, they can swiftly overrun entire reef systems and eat all the coral into bleached uninhabitable wasteland.  This leaves all of the multitudinous reef inhabitants homeless.  The reef skeletons dissolve in our newly acidified oceans and one of earth’s most diverse ecosystems becomes a weed-strewn graveyard. The starfish are hard to stop since they are provided with tremendous defenses: each animal is covered with 1-5 centimeter long razor sharp spines which in turn are covered with toxic saponins—soaplike chemicals which interact with cholesterols to tear holes in cell membranes.  The starfish can regenerate arms.  If removed from the water, the starfish develops holes in its body and loses its water, but it can swiftly reconstitute itself if placed back in the ocean.

Crown-of-thorns starfish wash up in Japan (BBC)

Fortunately there are some tough predators of the crown-of-thorns starfish.  Certain triggerfish, parrotfish, and blowfish can insouciantly crunch through the spines with hardened mouths.  Painted shrimp and polychaete worms can tear off and eat pieces of the starfish until the latter dies (whereupon the impatient scavengers devour the corpse).  Best of all, the magnificent Triton’s trumpet, a huge gastropod mollusk, can rasp the odious starfish to pieces with its sharpened radula and suck up the offending echinoderm!  Unfortunately, the fish are vanishing into the aquarium trade or the soup pot and the tritons have been killed en masse so their shells can be sold to tourists.  This results in a feedback loop wherein the crown-of-thorns devastate a reef to the extent that the predators can not survive at all.  The plague of starfish then descend of virgin reefs and kill them off too.

A plague of crown-of-thorns starfish (Photo: AFP/Getty Images)

Healthy reefs have a certain ability to fight off the crown-of-thorns star, but today’s reefs are coping with overfishing, invasive creatures, acidification, pollution, and fluctuating temperatures.  The crow-of-thorns is exploting these weaknesses (and the diminished stock of its predators) to run rampant.  Humans have stepped in late to try to kill of the rampaging multi-armed villains, but, for all of our skill at doing in other organisms, we seem to not be very good at killing these fiendish starfish.  They are difficult to rip apart.  They are hard to net or trap.  They are surprisingly resistant to punctures.  Recently divers have had success suppressing infestations by injecting the starfish all individually with sodium bisulphate (which echinoderms and my great uncle cannot abide, but which is relatively harmless to most other lifeforms).   Obviously this is an expensive and labor intensive solution (although if somebody wanted to hire me as a starfish bounty killer, I would not decline).

New frontiers of pest control (via DIVE QUEENSLAND)

The common name of the crown-of-thorns starfish is a reference to Christian mythology.  One of the tortures endured by Jesus was a crown woven of thorns (which pierced his temple and hurt him while simultaneously mocking his alleged crime—pretending to the throne of Judaea).  Throughout Christian art, the crown of thorns is the supreme crown of the king of kings which he wears during the passion or as he harrows the underworld.  The voracious starfish earned its sobriquet not by godliness, but by looking like a horrible alien crown made of thorns (and arguably also by bringing death and devastation to coral reefs).  I find it to be one of the most poetic and horrifying common names in all of taxonomy—and as the starfish destroys ecosystem after ecosystem, it seems fully earned.

A giant triton snail feeding on crown-of-thorns starfish. Image supplied by Australian Institute of Marine Science

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The Cornucopia

The cornucopia is an ancient symbol of harvest abundance.  It is commonly represented as a woven spiral basket overflowing with fruit, grains, vegetables, and other agricultural products.   In America it is one of the symbols of Thanksgiving time (second only to the magnificent turkey).  The wicker basket stuffed with fruits has become such a familiar image, that it is easy to overlook the Greco-Roman roots of the horn of plenty.

According to Greek legend, the cornucopia is the horn of Amalthea, the goat which served as foster mother to Zeus.   In the benign version of the myth, young Zeus, unaware of his own strength, accidentally broke the horn off of the goat while he was playing with her.   In the darker version, he slaughtered the goat when he reached manhood.  From her hide he fashioned his impenetrable aegis.  He gave her horn to the nymphs who had raised him, and this horn provided a magical eternal abundance of farm-raised food.  In memory of her generosity, he set her image in the stars as the constellation Capricorn.  There is yet another version of the cornucopia myth which Hercules broke the horn off of a river god and this became the original horn of plenty.

Infant Jupiter Fed by the Goat Amalthea (Jacob Jordaens, print)

Whatever its origin, the cornucopia remained a part of the classical pantheon.  It is most frequently seen in the hands of Ceres/Demeter, the goddess of agriculture and grains.  In Roman iconography the cornucopia was sometimes an attribute of Fortuna, the goddess of luck, and of the underworld god Pluto (who controlled the ground and thus was responsible for the gifts of the harvest).

Demeter holding a Cornucopia

I like the Hercules/river-god myth because it reflects on how important water is to agriculture, but I greatly prefer the myth of Zeus and his foster-mother which seems to embody the moral quandaries (and the promise of civilization) which are inherent in agriculture. The story—like that of Cain and Abel–hints at the replacement of hunting with herding and farming (indeed goats were the original domesticated animal).  Some cornucopias are now made of baked goods which makes the symbolic transition even more apparent.  The horn of plenty is an admirable symbol of humankind’s fundamental dependency on agriculture–which lies at the root of our civilization and our prosperity.  I am glad the cornucopia has kept its relevance for all of these thousands of years and has not been replaced by some tamer symbol.

The Feast of Saturn

Les Saturnales (Antoine-François Callet)

Today is the Feast of Saturn!  In Ancient Rome this holiday was officially celebrated on December 17 (XVI Kal. Jan.) and it initiated the multiple day festival of Saturnalia—the biggest holiday of the Roman Year. The Roman god Saturn was based on the Greek deity Cronus.  Although the Romans recognized that Saturn was a deposed ruler, a murderer, and a cannibal, Saturn was worshiped in Rome as an agricultural deity whose reign had been a golden age of abundance and innocence.  Saturn’s time had been one of gold–an age when people were naked, free, and kind. Jupiter’s age was one of iron when all men struggled greedily against one another–an age of wars, lawyers, oppression, and struggle.

Saturnalia was therefore a time to return to the imagined happiness of the past.  The cult statue of Saturn was freed from the shackles with which he was bound during the rest of the year and filled with olive oil (for the figure was hollow).  Schools and offices were closed so that special sacrifices could be made.  Great feasts were held and small presents were exchanged–particularly earthenware figurines called sigillaria and candles (which were a sort of symbol of the holiday and represented the return of light after the short dark days of the solstice).  There was a special seasonal market, the sigillaria. People decorated their houses and themselves with greenery and garlands.  Best of all, Rome’s famously rigid discipline was set aside during Saturnalia.  To quote the online Encyclopedia Romana:

During the holiday, restrictions were relaxed and the social order inverted. Gambling was allowed in public. Slaves were permitted to use dice and did not have to work. Instead of the toga, less formal dinner clothes (synthesis) were permitted, as was the pileus, a felt cap normally worn by the manumitted slave that symbolized the freedom of the season. Within the family, a Lord of Misrule was chosen. Slaves were treated as equals, allowed to wear their masters’ clothing, and be waited on at meal time in remembrance of an earlier golden age thought to have been ushered in by the god. In the Saturnalia, Lucian relates that “During My week the serious is barred; no business allowed. Drinking, noise and games and dice, appointing of kings and feasting of slaves, singing naked, clapping of frenzied hands, an occasional ducking of corked faces in icy water—such are the functions over which I preside.”

Various cults celebrated their mysteries during this time of year.  People from all walks of life lost themselves in uninhibited drinking, merrymaking, and fertility rituals.  Many Romans were born 9 months after Saturnalia (which would be approximately August 22^nd on our calendar).

Roman painting (Unknown Artist, Villa dei Misteri in Pompeii, Italy)

Saturnalia had started in Rome in 217 BCE after Rome had suffered a series of crushing defeats at the hands of the Carthaginians (and the citizens needed a morale booster), but the deep roots of the holiday stretch back to prehistory.  Additionally the various people whom Rome had conquered all had solstice rituals of their own–which became incorporated into Saturnalia.  The year-end ceremonies of the Gauls and Celts focused on evergreen trees particularly the yew.  In Roman Egypt, the ancient deities were still worshiped (indeed, worship of Isis spread through the Roman world).  During the solstice time Egyptians celebrated how their greatest god, Osiris, had returned to life after being murdered by Set. Strangely the Egyptians too focused their resurrection rituals around a tree–albeit the palm tree. Rome’s mightiest neighbor, the Persian Empire, burnt great fires for Mithras, a deathless god born in a cave on December 25th.   The Mithraic mysteries were particularly popular in the Roman military (although many of the details about the cult are unknown to us).  Across the complicated cosmopolitan Roman world, people of all classes and faiths dedicated themselves to pleasure and to getting through the cold darkness to a new year. Catullus called the time of Saturnalia, “optimo dierum” (the best of days) and that was definitely true in an empire which was otherwise beset by political unrest, war, agricultural failure, greed, injustice, and decline.

On an unrelated note, I will be away for a week to celebrate Christmas.  I might post some things here or I might be too busy eating, relaxing, and exchanging small presents with loved ones.  In the mean time I wish the very happiest of holidays to all of my family, friends, readers, and, in fact, everyone.