Today it was announced in the journal Nature that the mystery of Nectocaris pteryx, a problematic fossil species from the famous Burgess Shale deposits, has finally been solved. This tiny Invertebrate that lived in the Cambrian oceans 500 million years ago is, in fact, the oldest known cephalopod.
[UPDATE: The image I originally used in this post seems to have been removed from Wikipedia Commons. Follow this link to see before and after reconstructions.]
The original Nectocaris specimen was discovered 100 years ago, but it wasn’t formally described until 1976. However, the phylogenetic identity of the two inch long creature remained uncertain. It seemed to have similarities to both arthropods and chordates, but didn’t clearly fit into any known group. In this new report, researchers Martin Smith and Jean-Bernard Caron examined 91 additional specimens and came to the conclusion that N. pteryx is a mollusk, specifically a primitive, non-mineralized (i.e. shell-less) cephalopod. This revelation pushes the origins of cephalopods back at least 30 million years.
As we can see from the above reconstruction, Nectocaris resembled a modern cuttlefish. It had a flat “kite-shaped” body with large lateral fins, but only a single pair of long, grasping tentacles. It had a pair of non-faceted eyes on short stalks and a large anterior funnel, suggesting that cephalopod jet-propulsion evolved very early on. The lack of a shell disproves a long held assumption that shell-lessness is a relatively recent adaptation. It now seems that cephalopods didn’t evolve shells until much later, most likely “in response to increased levels of competition and predation in the Late Cambrian.”
Architeuthis "princeps" Modified from Verrill, 1879
At long last, we come to the end of my countdown of Ten Sensational Squids, a close-up look at a few of my favorite Teuthids. The top spot belongs, of course, to the rock star of the squid world, the darling of cryptozoology, and the species that got me started on this whole cephalopod obsession in the first place, the one, the only, the Giant Squid!
1. Architeuthis dux (Giant Squid)
First officially recognized by science in 1857, the Giant Squid was considered for more than a century to be the world’s largest Invertebrate (both in length and mass), a title that now appears to belong instead to the Antarctic species Mesonychoteuthis hamiltoni, the Colossal Squid. However, this claim is not universally accepted, and some researchers still ascribe to Architeuthis a maximum total length of 18 meters…nearly 60 feet! The more conservative estimate, and one that has become commonly accepted in recent years, is that female Giant Squid max out at a mantle length of 2.25 m (a little over 7 ft) with a total length of 13 m (~43 ft), which falls just short of the estimated 14 m Colossal Squid. (Male Architeuthis, at a mere 10 m, are a bit smaller than their mates.)
So, what is the source of this size disparity? It all seems to go back to a single specimen which washed ashore at Thimble Trickle Bay, Newfoundland on November 2, 1877 (unless it was Nov 8, 1879). This particular squid was reported to have had 35 foot tentacles and a mantle and head which together measured an astounding 20 feet long! This means that just the body of this monster would have exceeded the total length of most Architeuthis specimens known to modern science! For comparison, the largest Giant Squid currently on display is an 8.62 m (28.3 ft) specimen caught off the Falkland Islands in 2004. Based on current data and the fact that the elastic nature of squid tissues (particularly their feeding tentacles) makes them notoriously difficult to measure accurately, the veracity of this 130 year old report is highly suspect.
There are several other unverified reports of similarly sized Giant Squids from the later part of the Eighteenth Century, and the cryptozoological literature contains accounts of even bigger squids. Could it be possible that 60 ft (or greater) Giant Squid actually do exist, lurking undetected in the ocean depths? Of course! In fact, that would be sweet as hell. However, the facts as we know them just don’t quite support such a claim. For further reading on this, I highly recommend you check out Cameron McCormick’s (aka, The Lord Geekington) pair ofexcellent articles that explore this issue in more depth.
Bonavista Bay, Newfoundland specimen, circa 1981 (photo by derekkeats, from Flickr)
So now that we’ve tackled the size issue, what else to we know about the Giant Squid? They have long, narrow mantles, small ovoid fins, and huge eyes. Their arms and tentacles are lined with serrated suction cups. In life, they are a deep red color, but this is generally not retained in recovered specimens. Architeuthis is found world wide at depths of 300-1000 m (~984-3,280 ft). There may only be a single global species, A. dux, or possibly three, based on geographic distribution: A. dux (Atlantic), A. martensi (North Pacific), and A. sanctipauli (Southern). Wikipedia lists an additional five nominal species, and as many as 20 different species have been named over the years (many named from single, badly damaged specimens). They are predatory, feeding on fish and other, smaller squid, and, in turn, they themselves are preyed upon by Sperm Whales. If one assumes that Giant Squid make up a significant percentage of the whales’ diet, it would seem that are actually quite common, despite their uncanny ability to evade human detection. Because they are so seldom seen, however, little else is known about their behavior.
Melbourne Aquarium specimen, photo by Fir0002 (from Wikipedia)
Nearly all known Architeuthis specimens have been found either in the stomachs of Sperm Whales, washed up on shore, floating dead on the surface, or accidentally caught by deep-sea trawling. Sadly, none of these scenarios are kind to delicate soft tissues, and consequently, most specimens on display around the world are in pretty rough shape. The first photographs of a living adult Giant Squid were taken in 2002 on Goshiki Beach, Japan (the 13 ft individual was found at the surface and died soon after). It wouldn’t be until 2004 that a living Giant Squid was photographed in its natural habitat. Japanese researchers were able to lure a 26 ft Architeuthis to a baited line at a depth of 3,000 ft off Japan’s Ogasawara Islands. They took 500 pictures over the course of four hours, and you can see some of them at NationalGeographic.com. In 2006, the same research team filmed video of a live Giant Squid for the first time. Again using a baited line, the squid, an 11 ft female, was brought to the surface, as seen in this segment from Japanese television.
In October of last year (as reported right here on ISK), a professional underwater photographer captured the first pictures of Sperm Whales in the act of eating a Giant Squid. (You can see some of these amazing photos here.) This took place, yet again, in the waters off the Ogasawara Islands, further proving that Japan is the new center of modern Architeuthis research. Maybe one day soon someone will finally get footage of the legendary battle that is thought to take place when a hungry Sperm Whale sets his sights on an unsuspecting Giant Squid. This encounter has likely been mythologized, but it is mysteries like this, still unknown after nearly two centuries, that have helped make Architeuthis such a fixture in popular culture. Clearly, it is one of the Most Awesome Animals Ever.
So, waaaaay back in January I started this series to count down the ten types of squid I find most fascinating (in no particular order, more or less). I’m not exactly sure why I lost momentum so tremendously, but I figure it’s finally time to wrap things up. If you’ve been following along, I’m sure it will come as little surprise which species made the top two spots. (If you missed them, follow the Ten Sensational Squids tag for entries 10-3.)
2. Mesonychoteuthis hamiltoni (Colossal Squid)
photo by K.S. Bolstad (from tolweb.org)
This is it, the longest and heaviest known squid. In fact, M. hamiltoni is the largest living Invertebrate. Well, probably.
First identified in 1925 from remains found in the stomachs of Sperm Whales, the Colossal Squid lives only in Antarctic waters. The largest known specimen to date (even bigger than the one pictured above with teuthologist Steve O’Shea) was captured by a New Zealand fishing boat in 2007 and measured an estimated 10 m (~33 ft) in total length and weighed 495 kg (~1,091 lb). It is currently on display at the Musem of New Zealand Te Papa Tongarewa.
Most known Colossal Squid specimens are of immature individuals, but extrapolating from the sizes of beaks recovered from whales, scientists have estimated that adults can attain a total body length of up to 14 m (~46 ft)! Mesonychoteuthis also possesses the largest eyes of any animal, over a foot across—even though that record is still commonly awarded to the slightly smaller, but more famous, Giant Squid (Architeuthis dux). Compared to the Giant Squid, the Colossal Squid has shorter arms and tentacles, but possesses a mantle that is both longer and more robust—as much as 4m (~13 ft) long. Another notable difference between these two species is that the arms and tentacle clubs of M. hamiltoni sport vicious-looking hooks instead of suckers, a distinction that is nicely illustrated in this display at London’s Darwin Centre.
photo by Ben Templesmith
M. hamiltoni, which is the only known species of the genus Mesonychoteuthis, is Cranchiid squid, which makes it closely related to the wee Piglet Squid we encountered earlier in the countdown.
For more on the Colossal Squid, check out this slideshow by Tonmo.com which collects a lot of cool images and facts about this rarely seen giant.
February has been a hectic and exhausting month, and it turns out I needed a little break from my usual frenetic schedule of daily blog posts. (Plus I’ve become slightly addicted to the Winter Olympics.) Of course, during the down time I’ve ended up with a large backlog of material—not the least of which are the final two entries of the Ten Sensational Squids countdown. So, while I work on getting caught up, please enjoy the following video presentation by David Gallo, which reminds us all why cephalopods are so freakin’ awesome.
Pacific Bigfin Squid, photo by Richard E. Young (from tolweb.org)
Rare and poorly understood, Bigfin Squid were first formally defined in the 1990’s (although a single damaged specimen discovered in 1907 —M. talismani—has been subsequently assigned to the genus). Species of Magnapinna are characterized by small heads, large eyes, and very large fins that extend well beyond the posterior tip of the mantle. Almost all specimens described to date have been paralarvae or juveniles, and the adult forms are officially unknown. However, on multiple occasions in recent years, ROV submersibles have captured footage of a previously unknown large squid that is suspected to be the adult form of Magnapinna. Also known as the Long-arm Squid, these mysterious cephalopods are unlike anything previously observed.
photo by NOAA (from Wikipedia)
Its arms and tentacles (which are of equal length) are held perpendicular to the body and then angle downward (sometimes at 90°) at strange “elbows.” The relative length of arms/tentacles to the body is greater than in any other known squid (15-20 times the mantle length), and the total length of the animal is estimated to be as much as 8 meters (~26 feet). The Long-arm Squid has been observed in the Gulf of Mexico, the Indian Ocean, waters off Ghana and Brazil, and, as seen here, Hawaii.
T. danae is the sole species of the genus Taningia, and it is one of the largest known species of squid. It can attain a mantle length of 1.7 meters (5.58 ft) and weigh up to 61.4 kg (over 135 lb). (The specimen pictured above has ML of just over 1 meter.)
Apart from its impressive size, Taningia has many distinctive characteristics. The common name “Octopus Squid” (which also applies to the other species in the family Octopoteuthidae) reflects that adults only have eight arms, having lost their two tentacles during development. Two of these arms are tipped with large photophores. These light-emitting organs have muscular lids, giving the squid the ability to produce intense flashes of light when it attacks its prey. T. danae also has exceptionally large, muscular fins, which are fused on the dorsal midline and are nearly the length of the mantle.
In 2005, live footage (including the video below) of the the Dana Octopus Squid was shot by Japanese researchers at depths of 240-940 meters off the Ogasawara Islands in the North Pacific.
Additionally, here is another video that shows a squid that looks very much like Taningia danae that has attached itself to a light on a deep sea oil rig.
Also known as the Sparkling Enope Squid, W. scintillans is a small squid (~3″ long) found only in Japanese waters, where it is fished commercially. It is known for spectacular displays of bioluminescence and has 2-4 large black photophores on the tips of certain arms, 5 on each eyeball, and a galaxy of tiny photophores covering its body. The Firefly Squid is also the only cephalopod known to have color vision, possessing three visual pigments and a double-layered retina.
The video below is a clip from a Japanese talk show, and it features three different types of glowy sea life: Firefly Squid, bioluminescent plankton, and bioluminescent comb jelly. The squid part goes by pretty fast, but you get a good look at a school of W. scintillans all lit up!
After a brief pause to attempt (unsuccessfully) to recover from yet another mysterious “flu-like virus” (my third since October), the Sensational Squid Countdown resumes! If you are just joining us, here’s what we have so far…
H. cerasina - photo by Richard E. Young (from tolweb.org)
The Jewel Squids get their name from the distinctive large integumental photophores that make it look as though they’ve been run through a Bedazzler. They are moderate sized squid with long arms and short mantles (up to 33 mm long) with very small fins at the posterior tip. They are also commonly known as Cock-eyed Squid because their eyes are different sizes—the left eye is significantly larger than the right, is semitubular (not hemispherical), bulges out of the head, and is directed vertically, pointing up toward the surface.
S. hoylei - photo by R. Young
Depending on who you ask, the family Histioteuthidae contains either one or two genera, and up to 19 species. Some researchers place three of the species in the genus Stigmatoteuthis, which is distinct from Histioteuthis by the presence of even longer arms (relative to mantle length) and paired secondary reproductive organs.
Histioteuthids are oceanic squid found world-wide at depths of around 2500 ft. They have often been observed from submarines with their arms curled up over their heads in a way that give the appearance that the arms are tied in knots.
The next two squids in the countdown are not very well known, but both have achieved a small degree of Internet fame…which is similar to actual fame only not nearly as impressive.
8. Promachoteuthis sulcus
photo by R. Young (from tolweb.org)
P. sulcus is known from a single specimen collected in the south Atlantic at a depth of 1759-2000 meters. The holotype* is an immature female with a mantle length of 25mm. Its diagnostic characteristics include tentacles that are thicker at their base than the arms, and arm suckers that are bigger than the suckers on the tentacle clubs. However, the thing that got this obscure little squid noticed was this photo of its mouth, showing what seem to be disturbingly human-like teeth.
*A holotype is a single example of a specimen used to formally define a species.
photo by Richard E. Young (from tolweb.org)
These “teeth” are actually the circular, folded lips that surround the squid’s beak (which isn’t visible in this photo). Not long ago, this photo started making its way around the Internet, eventually getting the inevitable Lolcat treatment. Like so…
Considering that P. sulcus doesn’t have a common name yet, I think “Lolsquid” would be quite fitting.
7. Helicocranchia sp. (Piglet Squid)
H. pfefferi - photo by Richard E. Young (from tolweb.org)
Piglet Squid belong to the Cranchiidae (aka cranch squids, aka glass squids), a family of squids that include some of the smallest and largest known cephalopods. There are at least three species of Helicocranchia (although there may be as many as 14), and these small (mantle length ~100 mm) oceanic squids are found in tropical and subtropical waters world-wide. They are characterized by extremely large funnels that extend beyond their beaks and which resemble the snouts of pigs (hence the common name). Additionally, their arms jut out over the eyes like a shock of hair, and they have very tiny, and adorable, paddle-shaped fins. (Inset photo of Helicocranchia sp. by SERPENT Project.)
Additionally, their arms jut out over the eyes like a shock of hair, and they have very tiny, and adorable, paddle-shaped fins. (Inset photo of Helicocranchia sp. by 
