Wednesday, June 20, 2007

The Revenge of the Honkin' Big Animals!

Dear Constant Readers,

Y'know, it really doesn't seem like there are any books these days with nothing but random, interesting facts. Sure knowing the record for the largest male blue whale (107'1" !?) isn't theoretically of the utmost importance, but as a connoisseur of the random animal fact it still is something I enjoy knowing. It really gives that sense of wonder and nostalgia to my not-so-distant boyhood of reading outdated books. I literally travel to the ends of Rhode Island and Providence Plantations to read Gerald Wood's Animal Facts and Feats (part of the Guinness family)...well that and eat falafel pockets. As soon as I get over my miserly nature and cough up the 9 dollars (plus shipping) for the book, expect a grand finale to this trilogy started here.


Perhaps one of the most vaguest classification terms ever, this covers well over a dozen diverse phyla of generally elongated animals. Judging by how people discussing this video were baffled by what they were seeing, it is safe to say that nemerteans are among the least familiar "worms". Nemerteans are typically marine (occasionally freshwater and terrestrial) unsegmented predatory worms characterized by a proboscis. And they're huge, did I mention that? The worm in the video (a previously unknown species?) measured a fairly respectable 7 feet (2.1 m) in length. This very nice website has a picture of a 20 foot (6 m) long specimen, which about the same length as the record African Giant Earthworm (an entirely unrelated Annelid). The author points out that the biology of Nemerteans is virtually unknown, including how such an elongated animal can forage in the wide open without being eaten. I'd like to know why they need to be so outrageously elongated in the first place. It is known that they can reabsorb most of their bodies when resources are scarce and can reproduce asexually from fragments, so maybe that's part of the answer. Still, looking from the previous video and this one the length still seems a little...needless.

I led on that 20 feet was something impressive for this certainly isn't. Dr. Shimek has another photograph of a 40 foot (12 m) worm. And even that isn't too much considering the awe-inspiring (or nausea inspiring?) Lineus longissimus. He relates one story from the prominent E. Ray Lankester who measured a worm while playing golf near a beach that was over 100 feet (30 m) long stretched from hole to hole (not golf holes). A nemertean that washed up in St. Andrews, Scotland in 1864 was collected in a jar measuring 8" by 5", which it half filled. So while the nemertean was incredibly skinny (the norm is 5-10 mm wide!), Professor V. C. McIntosh measured out 30 yards (27.4 m) of it before the worm ruptured. He had measured less than half of it. This is where the occasionally cited figure of 180 feet (54.5 m) comes from...but it should have been at least that. So can this animal break the 200 foot (60 meter is you prefer) barrier, perhaps with the outrageous dinosaur Amphicoelias fragillimus as its primary contender? According to Gerald Wood, nemerteans can "shrink" to about 1/3 of their length, which would put this worm down to a measly 60 feet (18 m). These worms are apparently quite stretchy as well, exaggerating their length. But since Wood's account revealed that this wasn't measured on a beach (which I presumed at first) but post mortem by a scientist, should this length be accepted? Even if it isn't, a worm presumably 5-10 mm by 60 meters stretched (6-12,000 times longer than wide!) is biomechanically insane. How do the nerves work? How can it possibly stay intact? How can it do anything? Should I become a Nemerteanologist (neologism?) to find out?

I've always had a fear of living "spaghetti", and I think becoming a L. longissimus specialist is a bit out of the picture. As disgusting as that concept is (thanks Heuvelmans), I find internal parasites to be far more disturbing. Ugh, just the thought of this thing inside of me, biting some part of me I'm helpless to defend, draining my precious bodily fluids is....revolting to say the least. Tapeworms are not Nemerteans but an even simpler group called Platyhelminthes or flatworms. It includes planarians...but also other parasites like flukes. Wikipedia claims a length of 18 meters (~59 feet) from a dead website, but for once it seems to be under-exaggerating. Wood's book lists a tapeworm an utterly astounding 82 feet (25 m) taken from a human being. The longest tapeworm ever was found in a Sperm Whale: it measured 98'5" (30 m). It is curious to note that while people certainly do not have 80 feet of intestine, Sperm Whales have around 250 feet (~75 m) of tract. Are there even longer tapeworms out there? Who knows...but I am sufficiently disgusted by them to move on. If that amount of intestine is impressive to you, then it's segway time...

Elephant Seals

While Elephant Seals certainly are big and strange looking (and like buckets and not having them stolen), there is just one part of their anatomy which I just can't believe. According to Wood's book, a Southern Elephant Seal bull measuring 15'9" (4.8 m) had an intestinal tract measuring 662 feet or 202 meters long. That is 42 times as long as the seal itself! How does it cram itself into there? This paper (which I can't access) says the seals have intestines 25 times as long as themselves, so apparently that specimen was an exceptional one. Even then, that's a lot and what it is used for apparently isn't known. The abstract said it probably wasn't related to deep diving. Longer digestive systems are typically characteristics of herbivores; but if I recall my Vertebrate Bio textbook correctly, dolphins have long intestines to compensate for the fatty foods it eats. Still, 1/10 of a mile or more of intestine seems a bit...unnecessary for anything really.

Oh yes, their regular bodies are quite big too. The average size for a bull is (or probably, was) 16'6"(4.9 m) and around 5000 lbs (2200 kg) according to Wood. Females are about 1/3 the size of the males, making them impressively sexual dimorphic...for a vertebrate. Dr. Robert C. Murphy observed the flensing of a bull that was estimated to measure over 22 feet long originally (6.85 m) and weighed an incredible 5.5 tons (5 tonnes) the same size class as the seal's namesake. Murphy mentioned another seal that was a mere 18'4" (5.6 m) long, but was outrageously obese. Apparently it was so obese that even after half the blubber was removed, the men still had great difficulty moving it. It was never weighed or apparently even estimated, but judging from the sheer difficulty it very well could have been heaver that 5.5 tons. How something that size can move on its belly on land just seems ludicrous.

Equally absurd is that not only is the Southern Elephant Seal the biggest Carnivore (the Order) with the longest intestines around, Wood claims it has the most flexible spine of any vertebrate. I can't find a picture online, but the book definitely did have a picture with the seal bending over backwards to get a fish on its flippers. The Northern Elephant Seal can't do this, why would this one species need a much more flexible spine? Is it related to the increased mass? Does anyone know of a vertebrate that can contest this claim? Why do I end up asking so many questions?


Back to Invertebrates. Simpler yet than Platyhelminthes is this group containing the familiar jellyfish, corals, Portugeuse men o' war, and the somewhat familiar hydras. I won't get too into them here, but I will mention two that have been touted as the "longest animal". The impressive looking Lion's Mane Jellyfish certainly is far more massive than the worms mentioned so far; a specimen washed up in 1865 (wiki oddly says 1870) apparently had a bell diameter of 7'6" (2.3 m) with tentacles stretching an additional 120 feet (36.5 m)! So I guess you could say that this is the longest length recorded from an animal, but not the implied longest. There are anecdotes of larger specimens but, well, I'm kinda tired of dealing with those anecdotal reports.

It should be noted that there are claims, undoubtedly reliable, that the Siphonophore genus Praya can reach 30-50 meters (100 to 165) in length...apparently judging from sonar hits. This "creature" has two swimming organs at the end and is greatly elongated with numerous tentacles for capturing prey and thousands of stomach. Thousands you say? Siphonophores are made out of numerous different "individuals" acting in a coordinated manner as some sort of super-organism. Since the individuals really can't live on their own, it is quite ambiguous if this is in fact a colony or a single organism. But that really is just an arbitrary human definition now, isn't it?

Since Ernst Haeckel is long departed, I'm sure he won't mind me posting one of his awesome drawings of Siphonophores:


I guess there was no real transition into this topic, oh well. Despite being encased in armor and usually being quite small and numerous, some Arthropods can get considerably big indeed. Well, not the size of the pit bugs on Skull Island, but quite considerable none the less. Here is our first subject....don't ask:

Yes, I steal stuff from 4chan. This thing, occasionally confused for a living trilobyte or apparently some sort of Zerg (or Reaver?), is the giant isopod Bathynomus which can reach 18 inches. An isopod is a Crustacean familiar to most people as roly-polies, woodlice, pillbugs, et cetera. That's right, that enormous sub-Phylum has far more than just those decapods. Before I get ahead of myself, does anybody know of a phosphorescent species of isopod in Maine? They seem to be quite common but I have not currently been able to identify them.

I'll make no secret that centipedes scare the hell out of me. They're far too fast for having all those legs, the dang things are just so eerie looking. The largest centipede is occasionally cited as being Scolopendra galapagoensis, but it appears tales of its size have been greatly exaggerated. The largest species appears to be S. gigantea which can reach over a foot in length. You can read more about these monsters here.

Now on to the really big arthropods.

Over a month ago David made this neat little comparison pic which I intend to steal conceptually and modify somewhat. Oh yes, and Sordes, do you have any more information of that giant shrimp that you saw? I'm tantalized.

The leftmost animal is Arthropleura. The uppermost animal is the trilobite Isoletus and the animal below it is the American Lobster. In the center is me (1.74 meters tall) and the animal next to me is the Japanese Spider Crab. The animal farthest to the right is the Eurypterid Pterygotus.

Pterygotus was a gigantic Eurypterid, a group of large predatory chelicerates (horseshoe crabs, spiders, scorpions, et cetera). The largest known complete specimen measured 1.26 meters long (~4'), but there is evidence for specimens getting up to 2.3 meters (~7.5 feet) long. That is the hypothetical size portrayed in the illustration. There have been some old claims of 3 meter Eurypterids, but it doesn't seem like this is accepted anymore.

Arthropleura is another potential candidate for the largest Arthropod of all time. It is a centipede or millipede-like creature known as an Arthropleurid that is definitively known to get a meter in length. Tracks indicate that it could get 2 meters in length, but for some reason Wikipedia claims up to 3 meters. Once again I chose the more modest size...unless there is strong evidence to prove otherwise.

Certainly not the as massive at the other Arthropods, the Japanese Spider Crab (Macrocheira kaempferi) is still dimensionally shocking, especially for an extant animal. I used the same scale as the trilobite from the Pharyngula website (well, actually the paper it cites that I can't access) that is the source for these images. The commonly cited figure is a 3 meter/10 foot leg span, which I suppose the illustrated animal can live up to. Something that long and spindly being able to function encased in armor seems quite ludicrous, and it makes even larger claims (e.g. 8 meters/26 feet) quite hard to believe.

I already sorta mentioned the Trilobite and gave the link. For those of you that didn't look, Isotelus rex reached a pretty incredibly 0.72 meters long...for a trilobite.

I'm also portraying the American Lobster Homarus americanus with the same scale model as the giant trilobite. The portrayed lobster is 0.5 meters long (~20 inches) along the body. The record claim is 1.18 meters (3.9 feet), but it is not clear what that is measuring. Is that including the outstretched antennae, or the claws? So while this illustrative size may be overly modest, it still is quite impressive. The specimen weighed 22 kilograms (48 lbs), which is utterly astounding for an Arthropod. The Japanese Spider Crab nearly equals it with a weight of 20 kilograms (44 lbs).

So it looks like that wraps up this edition of the Revenge of the Honkin' Big Animals. I really wasn't expecting this to be so invertebrate heavy, but these sorts of things can be a tad bit unpredictable. I was expecting to transition from elephant seals to elephants, but it didn't quite work out. Since Anomalocaris evidently got in the same size-class as Arthropleura and Pterygotus I was thinking of sneaking it in here somewhere, but it is unfortunately Arthropod-related and not a member of the group itself* . These posts are mostly meant to cover the size of animals, but I anticipate that if I get sufficiently interested in one of these groups I'll most certainly give them a more detailed coverage.

*[Edit: There are some who claim that Anomalocaris and kin are indeed Arthropods, other who claim they fall outside the group, and other who claim that any similarities are convergent. More on this later]

During the course of writing this blog (yes, it actually is a multiple day affair), I had ordered Gerald Wood's book. You can probably anticipate some changes to this blog in the future, seeing as how I did not consult it for the big Arthropods. I won't write the finale just yet, but I'll let it ferment for a while. I've still also got to write a post covering the future of Cryptozoology, make up some more hypothetical animals, and of course attempt to write fiction. I've still fortunately got a summer left to try and do this all.


Addendum 6/26/07:

I got the 3rd Edition of The Guinness Book of Animal Facts & Feats, which has a photograph that really puts the size of elephants seals in perspective:

No information on this photo was given, but note how the animal doesn't even have a developed trunk yet.

Wikipedia's claim of lobsters weighing up to 22 kilograms and 1.18 meters along the body (48 lbs, 3'10") are exaggerations, but the apparent record is 1.067 meters from (extended?) claw to the tail and 20.13 kilograms (3'8" and 44 lb 6 oz). This is really outrageous in light that a thorough study in 1911 by Dr. Francis Herrick did not turn up a lobster larger than 25 lbs (11.3 kg). Even bigger sizes have been reported of course, there is a lobster grabbing a human in Olaus Magnus' famous 16th Century Carta Marina. The 18th Century Erik Pontoppidan mentioned a report of a lobster with a 6 foot (1.8 meter) claw spread that terrified fishermen. Given the oft-dubious nature of that time, these really are just amusing anecdotes. I'm pretty satisfied with a freakish arthropod as big as a moderately sized dog.

The largest validated lobster caught off Nova Scotia in February 1977. Other information on this photo is lacking. The tape measure isn't in the best of positions, so it is hard to tell if it actually does go up to 42 inches. Was it measured with the claws more stretched out? Regardless, I have seen another photograph of this specimen (or another similarly large one) in an unambiguous position that ridiculously dwarfed an average lobster. As far as outsized growth is concerned, this seems extreme.


Anonymous said...

I have another animal fact for you: A squirrel can run faster up a tree then it can on flat ground.

Mmm, that little falafel place...

I am not overly happy that now with the faster internet I can click on all of the link that you have, because some of those things I would rather not see, and I am quite happy not knowing that they exist.

You make some rather interesting segways in this one, but I really enjoy all of the pictures. The one with the green background is very pretty and the one with the doritos is rather creepy, but they look cool. Of course the picture tha tyou made is by far the best.

The Key Question said...

Arthropods and Doritos, I should've known... :D

Wow you certainly have some huge animals there. I write about more dimunitive critters like voles and planarians in my science blog Fresh Brainz.

Would you like to exchange blog links?

Best regards!

Anonymous said...

Very interesting post. Those elephant seals are really monstrous. There is one stuffed specimen in the entrance hall of the Museum of Natural History. This animal is really unbelievably huge, and the bulk is really unbelievable. I have once seen an
elephant seal in a zoo, but it was much smaller. I was also a bit shocked when I saw a stuffed walrus, which had also real monster-proportions. It was comparably short, but the overall bulk was really enormous. Sadly it was very dark in that room,
and I couldn't make good photographs. Another interesting fact about elephant seals is the colossal amount of food they consume. I can't remember the exact dates, but they catch and eat many tons of fish and squid over the year.

About the giant shrimps, I found some time ago something very interesting at underwatertimes:

The giant shrimp I saw was of similar body size, but it had very long and thin arms, and was therefore much longer.

Darren Naish said...

Congrats Cameron - I've just awarded you with a Thinking Blogger Award, for which you get your own snazzy little icon thing: go here to find out more. The post in which I gave you the award can be found here.

Darren Naish said...

Oh, and I've also just tagged you with the 'why do I blog?' meme: my article nominating you can be found here, and the meme tracker that shows the spread of the thread can be found here.

Anonymous said...

but it is unfortunately Arthropod-related and not a member of the group itself.

What definition of Arthropoda are you using...?

Cameron McCormick said...

Oh god, there hasn't been phylogenetic re-arranging since I've last looked, has there? I was defining it as a segmented animal with a chitinous exoskeleton and jointed appendages or tardigrades < insects for instance. Lacking appendages and chiton and having unique features (e.g. the pineapple ring mouth) would seem to place it outside of Arthropoda...unless this is some sort of highly derived stem group and/or Arthropoda is expanded to include things like tardigrades and onychophorans as well.

Cameron McCormick said...

Correction: Anomalocaris actually did have (unsegmented) appendages. This is pretty interesting stuff, so I'll try posting on this sometime in the near future.

Neil said...

hi. Just found this blog through darrens tetrapod zoology. I also have a strange fasination with the biggest animals in there groups (and the smallest) and found this article very interesting :)

Sordes said...

Hi Cameron! I just blogged a bit about giant lobsters. I saw a specimen of monstrous proportions in the NHM Berlin, mounted on a wall of biodiversity. It was really a giant, about the same size-class as the clouded leopard shown next to him, and well bigger than the lobster on the scale-drawing with the giant arthrpods in this blogpost:
BTW, I will probably blog about Arthopleura in the next time, because I have some nice photos of a life-sized model and even a fossil from the NHM Karlsruhe. This beast are even known from Germany, and some time ago relics of one were found which was about 2,3 m in length.