Tuesday, March 13, 2007

The Other Gigantic Squids

Dear Constant Readers,

You've heard me talk about the Mighty Mesonychoteuthis and the still impressive Giant Squid. You've even heard me address wacky Cryptozoological claims on gigantic cephalopods. I still can't believe I gave that one as much attention as I did. Much as how the Colossal Squid was completely out of the public eye until recently, there are several other species of big squid that are surprisingly poorly known. I imagine that somebody could make quite a story with a few of these species, assuming they have a recent specimen on hand.

Due to my obsession with obscurity, I'll be organizing these squid from the best known species to the most obscure. I wish there was an empirical way of determining that, but oh well, I'll just have to use my best reasoning (ooooh boy). I'll put the criterion for a "gigantic" squid at either having at least a 1 meter mantle length or a 6 meter total length. If there's any species I overlooked, please let me know!


Dosidicus gigas

Called the Humbolt squid, Jumbo (Flying) Squid, Diablo Rojo, et cetera, this is by far the most popularly known species here and is squided heavily in some Pacific locations. They belong to the family Ommastephidae, muscular predators that are powerful enough to eject themselves from that water and "fly" for a distance. Despite being harvested, the local squidermen are scared of the creatures, and there are tales of cannibalism and men being killed by the species. However, there is a pretty good show on PBS called "Encounters with Sea Monsters" where diver Bob Cranston demonstrated that they actually are rather inquisitive and probably quite intelligent creatures. They normally live in deep water 200-700 meters (600 to 2300 feet) down, and their behavior while lured on the surface by fishermen is abnormal. It's a fascinating show and I'd highly recommend watching it. While popularly known, the species doesn't seem to be well-known scientifically, which makes the squidery problematic. It is also far from clear how large this species grows. The maximum length is normally given at 1 meter (3'3") mantle length, 2 meters (6'6") including the tentacles, and a weight of 45 kg (~100 lbs). They only live a year or two and grow an astounding 1 mm a day. There is a mention of a squid nicknamed "Scar" that was 8 feet (2.4 m) long and 200 pounds (90 kg) at the end of this article. Wikipedia claims a 1.5 meter (4'11") mantle length (with a source) and Richard Ellis's book Encyclopedia of the Sea has a maximum size of 10 feet (~3 meters) and 300 pounds (135 kg), which is roughly equal. Perhaps rather than being due to the monsterization Architeuthis has succumbed to, maybe these size records actually do reflect abnormally old or even faster growing specimens. Even at more modest sizes, this is still one of the more fascinating animals in the ocean.




Taningia danae

This is a bizarre species of squid belonging to the family Octopoteuthidae. Its common name is the Dana Octopus Squid. This strange name is due to the fact that uniquely among the squids, the two long tentacles are entirely absent in adults. Very oddly for squids, two series of retractile hooks are present on the arms with suckers only at the ends. Of course, the Colossal squid also posesses this feature despite being distantly related. The fins are very large, fused to the middle of the mantle, and probably supply the majority of the locomotion. This species has a mantle length of up to 1.7 meters (5'6"), a total length of 2.3 meters (7'6"), and a weight of 61 kg (135 lbs). Despite being one of the world's largest squids, this species has become notable for having the world's largest light producing organs. These photophores are at the ends of two of the arms and are the size of lemons. Behavior for this species has been theorized, and recently it made the news for having been filmed by the Japanese. This species apparently can use its photophores to blind prey and apparently for courtship as well. Like many other deep-sea species this one was initially theorized to be sluggish, but has turned out to be a rather active predator as well. See the Tree of Life page, this article for the video, and this journal for more information. This species is apparently on its way to becoming fairly mainstream.




Onykia robusta

Belonging to a family called Onychoteuthidae or the hooksquids, this group is marked by two series of suckers on the arms and two series of hooks on the tentacle clubs. The phylogenetics of this group is undergoing upheavals, and this species was until recently in the genus Moroteuthis. According to Richard Ellis, its common name is the Pacific Giant Squid and Wikipedia calls it the Robust Clubhook Squid. Wiki keeps citing this book called "Cephalopods: A World Guide", I'll have to check it out to see if the claims are trustworthy. Despite having common names, mentions of this squid in popular culture are quite rare. I recall Ellis discussing one Japanese photo of a dying O. rubusta taken with forced perspective to make it look larger, but that's about as mainstream as it seems to have gotten. It is at least mentioned in books with some frequency, but in-depth articles are a rarity. It makes up a large portion of Sperm Whale diets and may be responsible for long scratches on the whales. The mantle length is commonly 1 meter (3'3"), but can get at least 1.615 m (5'3"), or over 2 meters (6'6"). The total length is either over 4 meters (13 feet) according to the last link, but Richard Ellis gives a figure of 19 feet (5.8 m). This may of course be due to post-mortem tentacle stretching like Architeuthis. Maybe somebody will come along and research this potentially charismatic species and finally clear up these uncertainties.




Magnapinna

A bizarre case to say the least. The description of this genus was originally based off of peculiar larvae with extremely large fins. The adult form was unknown, and for some reason Cryptozoologist Karl Shuker included them on a cryptid list. This is unfair to say the least, you already very well know that they are real flesh and blood animal! My criticisms of Cryptozoology will have to wait for another day. The first species M. talismani was described in 1907, although may not be a valid taxa anymore and could be synonymous with other species. M. pacifica was described in 1998 and M. sp. A finally got described as M. atlantica in 2006. M. sp. B and M. sp. C are still awaiting description. This could undergo a lot of taxonomic revision though. You might notice that these juveniles are a little small to say the least, apparently up to only around 95 mm (less than 4 inches). So what are these larvae doing on this post? Some researchers have concluded that the adult forms are indeed known, but only from videos. They're quite bizarre, to say the least. They retain the big fins; but now the arms and tentacles are held out with "elbows" and have become indistinguishable. I don't know of any other species of squid where this happened, and the 10 identical (or nearly identical) appendages are typically characteristics of belemnites. But this is indeed a relative of Chiroteuthid squids (see last entry). The tentacles and arms are extremely elongated, at least 10 times the mantle length and possibly being able to stretch to 15-20 times the mantle length. The overall length of the squids has been estimated at 7 meters (23 feet), although others say "at least" 8 meters (26 feet). Remarkably, many of the videos have made it online. The adults have yet to be captured, so once that happens, you can probably anticipate more news and a definitive placement at last.




Kondakovia longimana

This species belongs to the family Onychoteuthidae and is a fairly close relative of Onykia. Common names for this species are the Giant Warty Squid and the Longarm Octopus Squid. It is possible that the earliest specimens refer to a different species, so who knows what revision this species and other members of the group will go through. Unlike other hooksquids, this one has about 33 marginal suckers in addition to 33 hooks on the tentacle club. The Tree of Life webpage puts the mantle length at 0.74 m (2'5"), but Dr. Steve O'Shea's factsheet puts it at least 0.85 m (2'9") and "probably" over 1.15 m (3'9"). It could very well get larger, since it is only known from 5 complete adult specimens (and 12 fairly complete ones). One specimen from 2000, here, actually did make the news as the largest known complete specimen at over 2 meters (6'6") and 29 kg (63 lbs). It is the second largest Antarctic species after, of course, the Colossal Squid. Despite being so poorly known (it was first described in 1972), an estimated 2,100,000 tons of the species is eaten annually by Sperm Whales, their second largest food source.




Galiteuthis phyllura

This species belongs to the Cranchiidae family of squids marked by bloated bodies, short arms, and a large buoyancy chamber taking up the whole length of the mantle. With 60 species it is one of the larger squid families, but many species are poorly known. It belongs in the diverse Taoniinae sub-family and apparently forms a clade with the Colossal Squid, Mesonychoteuthis. The genus is defined by two rows of hooks on the tentacle clubs, long lance-like terminal fins, and typically grows to a mantle length of 0.66 m (2'2"). However, one species called Galiteuthis phyllura has an estimated mantle length of around 2.7 m (8'10"), exceeding the mantle length of Architeuthis, the Giant Squid! Even though it was based on fragmentary evidence, Dr. O'Shea mentions that the describer of the specimen was not one to exaggerate, so I think this report can be trusted. A wikipedian apparently translated the article from Russian, and the remains were apparently of a 40 cm (16") arm and 1.15 m (~4') tentacle; which makes sense given that they are proportionately very small. It was also remarked that while the mantle is incredibly long, it is also narrow, and the mass is much less than that of other large squids. Also remarkable is that this species has not had the least bit of media attention, making for some great potential.




Megalocranchia

This genus is also a member of the Taoniinae subfamily of the Cranchiidae, and is a fairly close relative of the Mesonychoteuthis/Galiteuthis clade. Suffice to say, there really doesn't seem to be much information on this genus at all. According to the Tree of Life page there are either four or six species, some of which reach up to 1.8 meters (5'11") in mantle length. It has a picture of a 2.7 meter (8'10") specimen of Megalocranchia fisheri, and apparently Megalocranchia maxima grows just as large. This quasi-English page has is another reference. It is not known if any of the other species grow around this size. Like other cranchids, it appears to be quite gelatinous overall and has very short arms. The short tentacles have clubs without suckers, unlike Galitheuthis and Mesonychoteuthis. The diagnostic characteristic for the genus are photophores on the digestive gland. At least female M. fisheri have additional photophores on the third arm pair. Dr. Steve O'Shea comments that a large Megalocranchid was just recently discovered off New Zealand and that a big, potential charismatic species like this could make a very good thesis for someone. I look forwards to when these species finally hit the news.




Asperoteuthis acanthoderma

This species actually has had a very recent news story, pulling it out of the extreme obscurity, but you'll see why I'm placing it last. It is only known from a handful of specimens from the Pacific, and one from the Atlantic (which caused the news story). It belongs to a family called Chiroteuthidae, slender, slow moving, gelatinous deep-sea squids which often have incredibly elongated tentacles. However, the only characteristic unique to the family is a bizarre larval form (termed doratopsis stage) with an incredibly long tail that appears to mimic colonial siphonophores. This genus is marked by strange "fins" on the tentacle clubs and extremely elongated tentacles. A specimen with a mantle length of 45 cm (~18") had a total length of 5.5 m (~18 feet), so it had tentacles almost 12 times as long as the mantle length. Specimens have been measured up to 78 cm mantle length (2'6") theoretically creating a squid up to around 9.5 meters (~30 feet) long. The reason for this extreme elongation is unknown and a little on the biomechanically ludicrous side if you ask me. And here's the cinch...there are no known adult specimens! If somebody happens to find one, it could theoretically rival Architeuthis and Mesonychoteuthis for the title of the longest cephalopod. And I think, properly told, this could make quite a news story.




And of course, why not compare all of the species?

Left to Right: Mesonychoteuthis, Architeuthis, Dosidicus, Taningia, Onykia, Magnapinna, Kondakovia, Galiteuthis, Megalocranchia, Asperoteuthis. There was confusion if the entire length and mantle length corresponded in Mesonychoteuthis and Onykia, and they have longer tentacles than is normally depicted. Dosidicus size is unclear and may need to be smaller (or larger?). Galiteuthis size is also speculative and may need revision (O'Shea estimated a much longer animal with different proportions). Magnapinna length is speculative and assumed the arms/tentacles were at "normal" 10 times the mantle length when estimated; entire length could theoretically be halved or doubled (if stretched). Asperoteuthis assumed tentacles 12 times longer than the mantle rather than 7; length may be significantly increased when adults are discovered.


I'm sorry that this post has taken so long to get up. Not only has the research taken a while, but I really haven't found an efficient way of illustrating and getting them online! They always lose a lot look nowhere near as good as the originals. Suffice to say, this post took me well over 20 hours to complete and my future ones probably won't be this in-depth!

Despite that, I hope you still enjoy whatever I end up posting. Could be anything. Even more cephalopods.

-Cameron

5 comments:

WK said...

Not sure if this qualifies:

Thysanoteuthis rhombus

http://www.cephbase.utmb.edu/spdb/speciesc.cfm?CephID=400

Cameron McCormick said...

Ooh, crap I think it does. According to the Tree of Life it has a 1 meter mantle, which is pretty dang big.

Well, hmm, I'll at least give the link for it from the Tree of Life here:

http://tolweb.org/Thysanoteuthis_rhombus

Toren Q Atkinson said...

Are you a member of tonmo.com ?

Dr Karl Shuker said...

Hi Cameron,

The reason I included Magnapinna in my update to Heuvelmans's cryptozoological checklist is that the postulated adult form, i.e. the long-arm squid, is currently known only from video evidence, not from any physical, tangible remains, so it is only supposition that it is indeed the adult Magnapinna - examination of a physical specimen may determine that it is an entirely unrelated, hitherto-undescribed species.

All the best,

Karl (not Kark!) Shuker

Cameron McCormick said...

Sorry Karl!

This is of course quite an old article and my opinions have changed somewhat on the frequent intersections between zoology and cryptozoology... I'll probably cover this again later.