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A School of Humboldt Squid

A School of Humboldt Squid

The world is ever changing.  Some organisms are incapable of changing their habitat or behavior to adapt to this mutability, whereas other animals are always doing unexpected things.  Among the latter are Humboldt squid (Dosidicus gigas) large aggressive cephalopods which are always popping up in unexpected locations.  These squid usually live in the open ocean at water depths between 200 & 700 m (660 to 2,300 feet) however they are apparently capable of swimming higher or lower.   Similarly although they used to live predominantly in the Humboldt Current (which runs from Tierra del Fuego up through Central America), it seems they are now migrating north.  Great schools of Humboldt squid were spotted this week off the coasts of Los Angeles.  Lately they have been reported as far north as Seattle, British Columbia, and even Alaska.  Scientists speculate that the squid are moving north in response to overfishing and climate change.  It also seems that the acidification of the ocean is changing their metabolism and driving them to more shallow water (which allows for greater oxygen uptake).

A Humboldt Squid with a Diver

A Humboldt Squid with a Diver

Humboldt squid can grow up to 1.5 meters (4.9 feet) in length and weigh as much as 50 kilograms (100 pounds).  They have eight swimming/grasping arms and two long lightning-fast hunting arms lined with toothed suckers.  The squid assemble in great schools of up to 1,200 individuals.  They communicate through bioluminescence and rapidly changing body color.  They are capable of group hunting—which makes a large school into a 50 ton super monster with ten thousand arms.  The squid feed opportunistically on everything they can catch including fish, crustaceans, and other cephalopods (sometimes including each other).  Oh, also they have large razor sharp beaks and are surprisingly intelligent. Humboldt squid have been known to attack divers (which can be a problem because of their size, spped, and sharp toothed suction cups) on the other hand they are said to be tasty is prepared correctly.

humboldt-attack-1

The Mountains of Antarctica as seen from the Southern Ocean

The great Southern Ocean which swirls in a clockwise circle around Antarctica is home to many of the Earth’s largest animals.  Blue whales come here to gorge on vast schools of krill. Among the icebergs and the towering waves, southern elephant seals (the largest member of the order Carnivora) fight duels to build their harems, and highly intelligent killer whales hunt together in pods.  There are populations of sperm whales living in the Southern ocean as well and these leviathans dive to the cold floor of the world hunting for the world’s largest mollusk, a huge cephalopod which can only be found in the Southern Ocean.  In fact this bizarre creature, the colossal squid (Mesonychoteuthis hamiltoni) is also the world’s largest invertebrate.  Also known as the Antarctic squid or the giant cranch squid, the colossal squid lives in the abyssal depths.  Unlike other squid, the colossal squid does not have tentacles–its powerful arms are studded with sharp hooks (much like the long-extinct belemnites).  Some of these hooks swivel while others have three barbs in the manner of a fish spear.

The Colossal Squid (Mesonychoteuthis hamiltoni)

The measurements of the colossal squid are staggering.  Its eye alone (the largest of any known creature) measures 27 centimetres (11 in).  A fully grown adult squid is estimated to be 12–15 metres (39–49ft) long.  Although giant squid have longer tentacles, the colossal squid a long stout mantles and are thus much more massive. Their upper weight limits are unknown but are well over 500 kg (+1000 lbs).

The colossal squid is believed to be an ambush predator, which lurks in the depths waiting for chaetognatha, other squid, and benthic fish (such as the Patagonian toothfish) to pounce upon.  It is hypothesized that they have a slow metabolism and do no need great reserves of food (unlike the energetic endothermic sperm whales which prey on them).  The colossal squid are believed to be sexually dimorphic—the females become much larger than the males.

A rare specimen of colossal squid

There is a reason that so much of this article is couched in ambivalent language such as “estimated”, “believed” and “probably”:  colossal squid live in an environment where humankind can barely venture.  The colossal squid are fast enough and clever enough to usually evade our nets, lines, and traps (although fishermen trying to catch Patagonian toothfish hooked a 450 kg (990 lb) specimen which was about 39 feet (13 m) long).  Additionally our submarines and submersible robots are too slow and noticeable too stalk the squid in the abyssal depths.  Other ocean creatures do not suffer from the same problem.  Juvenile colossal squid are eaten by beaked whales, elephant seals, sharks, toothfish, and even albatrosses, however the adult squid are so large that only massive sleeper sharks and giant sperm whales can threaten them.  Sperm whales are often covered with scars from their battles with the giants but the whales easily have the upper hand.  Sperm whale stomachs have been found filled with hooks and beaks (which coincidentally were much larger than those found on the largest squid specimens recovered by humans to date).

A very lovely photograph of an octopus kite by Nigel Bence

Ferrebeekeeper has written about actual flying squids which dart above the water waving their lateral fins to extend their gliding ability.  But real squid are not the only cephalopods that one sees in the skies–especially around springtime.  Two of the classical shapes for kites are squid & octopus shape.  The squid’s finned oblong shape, and the octopus’ round shape are perfect for balance and for catching the wind.  The dangling tentacles act perfectly as multiple tails. This spring has taken a cold gray turn—at least in New York, but while you are inside planning what to do during May, perhaps you should build some octopus and squid kites.  Here is a little gallery of images from different kite festivals and kite makers around the world.

A Commercially available Octopus kite/kit

Like squids and octopuses, none of the kites I had when growing up ever lasted long (well none of the ones I actually flew).  The beautiful range of mollusks suspended on the wind in the sky makes me wonder if I have any time to get out some dowels and crepe paper and build some more kites [sadly you do not have any such time—ed.].  As the soon as the  weather clears up again, I hope you enjoy some kite flying!

Sealife Mosaic from "the House of the Dancing Faun" in Pompeii (ca. 1st century AD)

So much of Roman artwork is lost.  Except in remarkable circumstances, Roman paintings, textiles, and drawings were too fragile to survive the long centuries of neglect.  Almost all are now long gone.  Fortunately the Romans were masterful mosaic artists and mosaics are durable. Many mosaics concerning all sorts of aspects of classical life have lasted through the millennia.  Some of these tile artworks present the loves of gods or the wars of men but quite a few are more humble and show the aftermath of a banquet or fishermen hauling in a day’s catch .  Since Romans ate a huge amount of seafood, it is no surprise that many mosaics showcase mollusks of one sort of another.  Here is a gallery of Roman mosaics featuring octopuses, squids, bivalves, or snails.  I have tried to add as much information as I could but some of the photos I found were poorly labeled

Marine Life Mosaic from House viii in Pompeii demonstrating the vermiculatum technique (ca. 2nd century BC)

Detail of a Roman bath mosaic depicting a murex. (ca. late second to early first century BC)

Floor mosaic from "House of the Faun" Pompeii: Cat with bird, ducks, and sea life.

Ancient Roman Mosaic Prtraying Sealife from the British Museum

Triton with an octopus and squid (Forum Baths, Herculaneum)

Roman Mosaic of an Octopus

Modern mosaic makers were inspired by the Roman example and flamboyant cephalopods are a major theme of contemporary mosaics as well as ancient ones.  Here are some modern octopus and squid mosaics for millionaires’ swimming pools, elementary schools, or even everyday bathrooms.  Enjoy!

Modern copy of a Roman era mosaic from Milreu, Portugal

A Kraken for the bottom of a swimming pool (by Laurel Studios)

Octopus Mosaic for a public school

Contemporary Octopus Mosaic

A squid mosaic in downtown Pittsburgh, Pennsylvania

Octopus Mosaic from Seattle Country Day School

Navigation Mosaic by Mia Tavonatti

Berry's Bobtail Squid (Euprymna berryi) photo by Rokus Groeneveld

I have written before about the beautiful cuttlefish (marine mollusks of the order Sepiida). Cuttlefish are closely related to another order of mollusks, the Sepiolida, or bobtail squid, which are perhaps even more endearing.  With huge expressive eyes, tiny little tentacles, and opalescent skin, bobtail squids look like they were designed by a Sanrio artist having a strange day.  Sepiolida cephalopods appear to be all head (they are also known as dumpling squid or stubby squid because of this shape)–and their large rounded navigation fins, which stick out like Dumbo’s ears only add to the impression.   Members of the Sepiolida do not have cuttlebones but they are far more similar to cuttlefish than to other squid—perhaps their taxonomical classification will change as they are better understood.

Southern Dumpling Squid (Euprymna tasmanica) photo by David Mitchell

There are approximately 70 known species of bobtail squid living in the shallow coastal waters from the Mediterranean, to the Indian Ocean, to the Pacific.  To quote the Tree of Life Website, “Members of the Sepiolida are short (mostly 2-8 cm), broad cephalopods with a rounded posterior mantle.” The animals are gifted hunters which eat shrimp, arthropods, and other small animals which they chomp apart with a horny beak at the center of their arms. During the day, bobtail squid bury themselves in the sand with only their eyes protruding and then they hunt at night.  Certain species of bobtail squid are known to be poisonous, like the lovely Striped Pyjama Squid (Sepioloidea lineolata).  This poison is not well understood and may be contained in the slime produced by the creatures.

Striped Pyjama Squid (Sepioloidea lineolata) photo by Tony Brown

Bobtail squid are bioluminescent and they use this ability to disguise their profile when viewed from below–a helpful sort of camouflage which serves them as predators and prevents them from becoming prey.  Young bobtail squid are not born with the bioluminescent bacteria but must capture them from the water column in order to start the symbiotic colony within their own bodies.  The symbiotic relation between the bobtail squid and the bacterial colony has been much studied in the laboratory.

Bobtail Squid (photo by Adam Minu)

It was thanks to such studies that scientists first began to understand the method through which bacteria communicate with each other.  Called “quorum sensing”, such communication takes place within a group of bacteria by means of signaling molecules.  The chemical conversations allow bacteria to respond quickly and in aggregate to changes in their environment (to such a degree that a bobtail squid can tell the bacteria within its own tissues how much to fluoresce and can thereby determine its own luminosity by communicating with millions of living entities inside itself).  I have written before about how critical bacteria are to the planet and the Earth’s ecosystem.  Studying the bobtail squid provided the first understanding of the way that bacteria communicate with each other, but we are now beginning to suspect that such communication might take place on a vast—perhaps even a global—scale.

Juvenile Common Botail Squid (Sepietta oweniana)

An octopus or squid theme jar from the Knossos Palace in Crete (ca. 1500 BC)

Since the last two posts concerning mollusks have also involved the classical Mediterranean world (where cuttlefish ink was used for writing/drawing and murex mucous was employed as a costly dye), I am going to continue the theme by presenting a gallery of octopus vessels from ancient Greece.

A Mycenaean Octopus Vase (from beyondbooks.com)

Most of these vessels are from the Minoan culture which flourished from 2700 BC -1500 BC or from the Mycenaean city states which were most successful between 2000 BC and 1100 BC (when an incursion of mysterious aggressive “sea people” apparently destroyed the great palace kingdoms). Such vases and jars were made by trained craftsmen and were prized throughout the Levant.

Stirrup jar with octopus, (ca. 1200–1100 b.c.; Late Helladic IIIC, The Metropolitan Museum of Art)

Vase of the Late Minoan I Period (about 1600-1100 B. C.) found on Gournia, Crete Courtesy of the Metropolitan Museum of Art."

Minoan "Palace style," vessel (ca. 15th century BCE, Athens National Museum)

Because we only know tantalizing fragments about life in ancient Crete or in the Mycenaean palace states, the artifacts from that age have been subject to much conjecture and speculation.  These lovely octopus vases have led some thinkers into believing that Minoans worshipped the sea and the creatures therein.  Other scholars have conjectured that the ancient Cretans looked to octopus tentacles as inspiration for that characteristic Minoan architectural conceit, the labyrinth.  The real symbolic or ritual purpose of the octopus motif remains unclear and probably always will.  What is certain is that the vases, drinking vessels, and jars are quite lovely.  The octopus motif originated around 1500 BC and by the Minoan period the so-called “marine style” of decorating pottery had become even more prevalent and diverse.  Some ceramics were covered with fish, octopuses, dolphins, and crabs.  In fact there was even a vessel covered with murexes. Perhaps these people simply liked octopuses and sea creatures. I can certainly understand that motivation!

Terracotta rhyton painted in "Marine Style" with murexes (Zakros, Late Minoan IB, ca. 1525/1500-1450 B.C.) (Courtesy Onassis Public Benefit Foundation)

Rhyton, drinking vessel with painted octopus (From the Aegean, found in Ugarit "Minet-el-Beida", Syria. Late Bronze. Terracotta)

Minoan Amphora w Octopus Motif , New Palace Period , Knossos , Crete

I’m always surprised by how numerous and varied the cephalopods are.  A quick jaunt down the taxonomical branches of their family tree reveals marvelous creatures to delight even the most jaded marine biologist–and, we are still discovering new cephalopods all of the time!

Today’s post, however, is not a larger examination of squids and allied cephalopods (although I have been thinking about adding a “mollusk” category to this blog and embarking, to some small degree, on such a task), instead we are concentrating on a very specific and unusual behavior practiced by certain squid in dire circumstances—namely flying.

A Red Flying Squid (Ommastrephes bartramii) zips along above the Sea of Japan. Notice how the squid has altered its shape to become aerodynamic.  Original photograph by Geoff Jones.

Flying fish are well known for their aerial prowess, but flying mollusks (for such is, of course, what squid are) seem almost to strain credibility.  To imagine a cousin to the stolid clam whipping through the air propelled by jet propulsion takes temerity…or at least it would, if such behavior were not well documented.  Many different species of squid from around the world have been observed leaping out of the water to avoid heavier predators. In fact the common names of several commercially important squid reflect this: Spanish fishermen hunt for voladores “flyers”, Nototodarus gouldi is commonly known as the arrow squid, and Japanese Flying Squid (Todarodes pacificus) is a mainstay in Ika Sushi.

The Caribbean Reef Squid (Sepioteuthis sepioidea) propels itself above the waves with a jet of water.

These flying squid are not merely popping out of the water for a moment before returning: some of the creatures form their tentacles into a fan/wing then stretch out a membrane running along their body and actively flap the fins at the front of their mantle.  The Journal of Molluscan Studies cites an example of a squid flying 6 meters (20 feet) above the water for a total distance of 55 meters (180 feet) thus outdoing the Wright Brothers’ first flight!  I wonder if the ancient belemnites (extinct squid-like cephalopods of the past) were ever able to fly in such a way or if this is a new feature of cephalopod evolution–maybe in a few million more years we will have even more deft flying mollusks zipping around with the sparrows.

A cool acronym…or a harbinger of days to come?

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