Why is the Giant Squid so giant?

Steve O'Shea

TONMO Supporter
Supporter
Joined
Nov 19, 2002
Messages
4,671
Interesting distinction between neoteny and paedomorphosis, John - I was hoping this thread/question would be picked up at some point, as it was left dangling; thanks. I'd like to explore this a little further myself, but right now I don't have time on my side. If anyone else has anything to contribute then PLEASE jump in.

Re this prehistoric 'mega squid' - that was a hypothetical case I gave (that it could be shrinking in time, as opposed to increasing). There is a tendency for people to think of the ancestral Architeuthis as being smaller than the modern-day animal, attaining its present size by way of gradual or spontaneous increase in size (depends whether you believe in periods of stasis followed by rapid bursts of change/evolution [punctuated], or the gradual acquisition of characters/change of character states [eg., size] through time). Who knows ...... But the animal could equally be decreasing in size as our fossil record really is quite poor for these animals/squid in general/and for octopus almost non-existent.

The maximums for the modern-day Architeuthis, almost certainly of which a single species, Architeuthis dux, exists world wide, are:
Length (mantle; female) 2.5m
Length (mantle; male) 1.7m

Total length (female, relaxed, not stretched like a rubber band, incl tentacles): 13m
Total length (male, relaxed, not stretched like a rubber band, incl tentacles): 10m

Total weight (female): 275kg
Total weight (male): 150kg

These are slightly larger than the largest specimens I've ever seen (of 96 of them). Even though 60 foot, or ~ 20m, is frequently cited as the max, and the specimen on which this was based was actually a New Zealand specimen that washed ashore back in the 1880's (or thereabouts), the specimen was NOT measured with a ruler, tape measure or yard stick - it was PACED (and this is clearly stated in the original publication) - this is overlooked in any subsequent citation to it. Moreover, this specimen almost certainly had been regurgitated from a whale stomach (in those bad old days) and was partially digested (and thus its length exagerated further, as they go to mush). Its tentacles were probably stretched out the thickness of a rubber band to make it larger/longer still (this can be done) ..... and the chap who 'paced' it probably took 'baby steps' and then exagerated some. People need their monsters, but the fact is they do not grow this large.

No specimen remotely approaching this size has been recorded since, anywhere, and so many have been measured world-wide now. All specimens we get in New Zealand are fully mature, and thus unlikely to grow any larger (they're not babies); those caught overseas/stranded are similarly almost always fully mature, and agree with the maximum sizes we get in NZ specimens (if not being slightly smaller/shorter).

Trying to reduce the size of this animal is, however, just about impossible - people refuse to believe it is actually smaller than it is. No matter what I do the same old hogwash is perpetuated in nearly every report ... and if its not its total length that they blow out of proportion then it is the size of its eyes, beaks or suckers...... It would be so much easier to raise $$ to find this animal if I was prepared to perpetuate the nonsense ... maybe I should just continue like everyone else?

Cheers
O
 
Joined
Dec 24, 2002
Messages
1,169
Steve,

Ah, well... I will admit that I would like to think that there were some monsters out there. For some reason, people need their monsters. Where I live the local legend is Bigfoot. A distant cousin has the Loch Ness Monster. I can name a million cryptozoological legends, each more fantastic than the last. From seas serpents to the chupacabras, I think that people need their monsters. I think that somehow these stories play on some deep seated desire to be part of something much bigger than ourselves. Go see "The Lord of the Rings: The Two Towers"... Samwise has a monologue which I think defines this to a tee.

I don't blame you for getting a bit frustrated. My first love was astronomy, and while I believe in life on many, many other worlds, I can't get myself to believe in the standard UFO stuff. Oh, I would LOVE to see a flying saucer complete with aliens, and there very well may be some out there, but the reality of science so often gets buried in the pseudoscience of legend and folklore. It frustrates me because science can be rewarding and so much more interesting than people are willing to believe. But the folklore can make for some great reading, and fun, if you're willing to treat it as such.

Heck, a sixty-foot Archeteuthis would be a sight to say the least. Maybe they exist, maybe they don't. Let's not detract from the fact that the deep sea has incredible lifeforms the likes of which we probably have not even considered yet.

If this doesn't make you feel better, then we could always fake an ammonite sighting and sell it to the Discovery Channel! :P

Just spending time waiting for the eventual cephalopod takeover,

John
 

Steve O'Shea

TONMO Supporter
Supporter
Joined
Nov 19, 2002
Messages
4,671
Fujisawas Sake said:
Just spending time waiting for the eventual cephalopod takeover
...I don't think this was a good month to quit smoking. How long have we got?

That ammonite is out there ... not necessarily on this planet .... but it would sure be a buzz to go looking for it. I've often dreamed of doing the sub thing down 9000 metres off northeastern New Zealand (into the Kermadec Trench) .... it's never been explored you know .... only problem is the deeper you go the reduced likelihood of finding the ammonite (implosion) [unless that shell is fluid filled]. Spirula manages to do it ... astronomical depths .... and you can crumble its shell in your hands (it's not that strong) .... so just maybe there's hope for us yet. In fact, why don't we build a submersible in the shape of a Spirula shell??? Hmmmmm.
 
Joined
Dec 24, 2002
Messages
1,169
Steve O'Shea said:
...I don't think this was a good month to quit smoking. How long have we got?

Steve,

According to Animal Planet's "The Future is Wild", we have about 200 million years before the the Squid Dominion. You can find out more at:

http://animal.discovery.com/convergence/futureiswild/futureiswild.html

I like specials like these... I have two books by Dougal Dixon; After Man: A Zoology of the Future" and The New Dinosaurs: An Alternative Evolution. Yeah, for the most part its sci-fi, but evolution never stops, and its fun to dream about what lies ahead. Oh, and Steve, your 120 foot squid is only 200 million years away, and the trees belong to the Squibbons...

You really think that there are still ammonites out there?
 

Steve O'Shea

TONMO Supporter
Supporter
Joined
Nov 19, 2002
Messages
4,671
I think the chance of finding a live ammonite today is greater than the chance of a 120-foot-long terrestrial squid in 200 million years, unless there are rather serious changes in the atmosphere and gravity, and if so I don't think we'll have squibbons. Some many-armed thing could occur on land, look like a squid, but likely through some quirk of evolutionary convergence only. ...imagine that slime trail :yuck:

Maybe ammonites weren't even squid .... maybe the shells are simple buoyancy chambers of an extinct mega-slug. You have to wonder about those asymmetrical ones don't you ... perhaps they were benthic, screwing themselves into the sediment .... maybe they still are out there in the abyss.
 
Joined
Dec 24, 2002
Messages
1,169
Steve,

Chances are that the climate in 200 million years will be a lot different. As far as gravity, well... I doubt it, unless Earth loses some serious mass.

As far as cephs making the transition to land... Well, evolution is a harsh mistress. The types of selective pressures needed over time to create a land-walking ceph... Hmm... Hate to say this, but that's a real brain scratcher. I can't completely discount the possibility, only because I can't shake the feeling that Molluscs share a common, if not INCREDIBLY distant, relationship with the Arthropods and Annelids. The move to land would be tumultuous at best, and how they would solve the problem of non-skeletal muscle based movement... What would result would be akin to calling a therapsid reptile a human... It wouldn't be a cephalopod anymore, only a very, very derived descendant.

Well, anyway... About your ammonite idea: What if they were gastropods, but of the Order Pteropoda? A massive group of sea butterflies may sound farfetched, but so does the idea of undersea "lakes" and chemosynthetic-based ecologies. What if they were related to the Scaphopoda? If they were, let's hijack a sub and start digging!! :biggrin2:

Also, what if the ammonites were actually paraphyletic groups of molluscs? Maybe some may have been cephs, others gastros, or even some other, long extinct Order? The shells could have been homologous across the early mollscan line. Food for thought

What really bakes my noodle is, what if some of these shells were INTERNAL? :shock:

:lol: *sigh* Only time will tell. Thanks for the reply!

Sushi and Sake,

John
 

Steve O'Shea

TONMO Supporter
Supporter
Joined
Nov 19, 2002
Messages
4,671
The pteropod idea is not so far-fetched John - it is something I've considered myself. Moreover, I am absolutely convinced that a number of ammonite shells were completely internalised - we had this discussion on an earlier board (since gone ... and I regret now not having transferred the content over).

It would pay, if you want to continue with this theme (internal vs external and anything to do with ammonites) to start up a separate topic on this board. By doing this we can clearly separate the two topics (giant squid and ammonites), and maintain succinct threads. I'm sure Phil would be pleased to see this subject up and running again also.

There's much to be added on this subject. I actually have Neil Landman (AMNH) visiting early next year (oooooh....that's tomorrow), and one of the things I wish to discuss with him is this internal/external business, and more info on the aptychus as a jaw or gizzard plate. The 'radular' (adj) teeth described for some of these ammonites are also more similar to gizzard teeth ..... I'll try and get him to bring some specimens with him so I can do some photography and post here. For all the world these structures resemble those we see in some opisthobranchs today (eg., Philine spp.).... There is no way that the buccal musculature associated with operating these jaws/aptychi could be accommodated within the last chamber of the ammonite, if their basic body plan was anything akin to that of Nautilus (I realise the relationship is distant). My only concern re the scaphopod/slug/gastropod/pteropod relationship is this siphuncle.

I'm rambling, but you've sparked my interest in the subject again.
Cheers
O
 

tonmo

Cthulhu
Staff member
Site Owner
Joined
May 30, 2000
Messages
10,881
we had this discussion on an earlier board (since gone ... and I regret now not having transferred the content over).
I'll see what I can dig up.
 
Joined
Jan 6, 2003
Messages
476
Melissa the correct answer is species. There are over 200 species of Squid in the ocean and each of these species grow to different lengths, sizes, and have different characteristics. Archetuthus which i dont think i spelled right but who cares is one of the species that can grow up to about 55 to even 60 feet in length including the 2 long prey grabing tentacles. Thats why Giant Squid are so big its because of the species type and this kind of species of quid that grows very large just happen to grow the biggest in size out of all the Squid species there are.
 

Steve O'Shea

TONMO Supporter
Supporter
Joined
Nov 19, 2002
Messages
4,671
....and there you have it :wink:

Welcome aboard Armstrong; you were rather busy there yesterday weren't you ... tiz hard to keep up right now.

Are you studying cephalopods, or is this a hobby of yours?
Cheers
Steve
 
Joined
Dec 24, 2002
Messages
1,169
ALERT!!! NEOTENY NEWS!!!

D'OH!! *slaps head*

Sorry folks... upon further review of my notes, I should re-state the neoteny thing...

Paedomorphosis and Neoteny are pretty much the same... Neoteny is the retention of juvenile characteristics during and beyond sexual maturity... its the SAME as paedomorphosis.

BUT... there are two types:

Obligatory: Where juvenile characteristics are always retained

Facultative: Where environmental factors affect the neotenic characteristics and metamorphosis...

Thanks for your patience folks!

Sushi and Sake,

John
 

Steve O'Shea

TONMO Supporter
Supporter
Joined
Nov 19, 2002
Messages
4,671
Another explanation for giant squid 'gigantism' is copied below, taken from the link:

http://www.cnn.com/2003/US/South/01/23/arkansas.fossil.ap/index.html

Wherein "The professor said the cephalopod found by the students is a pathological giant, which possibly suffered from parasitic castration. In other words, parasitic algae destroyed the reproductive organs of the creature and the creature continued to grow."

....but for acquired gigantism like this to be passed from one generation to the next, as in inheritance of acquired characteristics, one would need one's reproductive organs .... and the likelihood of these being available (or existing) following 'parasitic castration' is pretty remote (having trees in your tubes sounds painful). Guess our good giant nautiloid was a dead-end in evolutionary history. I do wonder why the report singles out parasitic algae though ... have these a habit of infesting cephalopod reproductive systems?
 
Joined
Jan 25, 2003
Messages
18
G'day Folks,
Thoroughly fascinating subjects you guys have here. I have been lost for two days in this site now and still cant find the will to move on!!!
Anyways, I am a non educated guy when it comes to scientific research, but I have spent hundreds and hundreds of hours reading everything i can about what makes animals and physics tick.
I noticed here the refections of how a squid uses his tentacles.
I am a very keen fisherman and every winter here in south east Queensland, Australia the squid come in to breed. Most of my catches of squid have been with the use of prawn style jigs or scoop nets, both used at night. I am yet to catch a squid by the tentacles on its first attack of the jig. They move in for the kill immediately with its arms as thier first attack. If I miss setting the hooks on that attempt, the squid will use its tentacles to "taste" the jig to see if its edible. If it decides its not worth trying again you will in no way entice it into another take.
As for how it postures while actively hunting under the lights, i have noticed that the tentacles will in most cases be retracted short and held slightly wider than thier arms.
There are two main types of squid here that I have access to. The most prolific is an Arrow squid, and the second is what we call a tiger squid.

I do have a question tho.

Do squid and octopus have an olfactory system of sorts for detecting scents?

I should have stayed at school and followed my childhood dream and become a biologist i think. A little late now to start uni for a degree at 38.

Keep up the fascinating studies folks, Take care and keep smiling. :smile:)

Tony.
 

Architeuthoceras

Architeuthis
Staff member
Moderator (Staff)
Joined
Nov 19, 2002
Messages
2,460
In the article by Manger, Meeks & Stephen I refered to in this thread (Dr. Manger is the professor interviewed in the news article above). They refer to living Giant cephalopods as phyletic giants with a reference to Cope's Rule. They also refer to living pathologic giant gastropods that have been castrated by nematodes (I dont know where the algae fits in). Alot of Actinoceroid (Rayonnoceras) fossils have been found in Arkansas that are less than 1 meter long, I think the fossil in the article is only the second Giant Actinoceroid found.

Dwarf ammonites have also been found. I have a picture on my site.
http://ammonoid.topcities.com/turonian.htm
The Pteroscaphites is considered a progenetic dwarf offshoot of the larger Scaphites.

:nautilus:
 

Steve O'Shea

TONMO Supporter
Supporter
Joined
Nov 19, 2002
Messages
4,671
heydiddlesquiddle said:
Do squid and octopus have an olfactory system of sorts for detecting scents?

Heydiddlesquiddle, aka Tony, howdo. I have a lot riding on this very question myself. I am aware that pheromones have been identified in Sepia (cuttlefish)......but just how many squid release pheromones I don't know (yet). This is something we are to look at this coming year.

Neither squid nor octopus have an obvious 'nose', but a system is in place, somewhere. More to follow soon.

That parasitic algal business being responsible for neutering the aforementioned beast is probably another example of the press getting things all wrong. Thanks Kevin.
O
 

Jean

Colossal Squid
Registered
Joined
Nov 19, 2002
Messages
4,218
Hiya Heydiddlesqiddle, I'm certain that arrows ( Nototodarus spp anyway!) have some sort of olfactory system, no real evidence to support this, but on the odd occasion we've held live ones, they've been held in a very large and dark tank (Steve you'll know the ones I mean, the big concrete ponds under the lab building at Portobello!) Anyhow when we've fed (or attempted to feed) them they will be nowhere in sight but shortly after the food (usually filleted fish, until such times as we can get the fish traps out to catch live food!) hits the water they appear out of the gloom. Now unless they have some sort of super xray vision, my feeling is that they smell the fish.

BTW it's never too late to enrol at varsity, my Mum has this year and she's 64 in May!!

J
 
Joined
Jan 25, 2003
Messages
18
Thanks Steve,
I'm glad to be here learning more and more each few mins :smile:

Thanks also Jean,
I have noticed that squid can react to other senses incredibly quickly.
I fish for squid always on the new moon nights as they are the darkest and i fish on piers which have lights on them. I generally dont fish under the lights due to crowds so i move away 30 feet or more and jig the shadowed areas for better results.
During mid winter here when the squid are around, if the action is slow I will tie on a pair of bean sinkers about 2 inches long on separate loops so they rattle together with the retrieve, and cast them out as far as i can. The retrieve i make is as fast as i can wind while jigging the rod furiously. Within seconds of the sinkers leaving the water the squid will start to appear. I have counted 23 squid appearing after one cast once before but that was outstanding, usually its 6 or 8 squid that appear. This sort of brings me to thinking they use a sense of vibration as well as extremely good vision for thier major hunting techniques. I have tried fish scents in the water before and the squid only appear after the bait fish begin to school around. That's what was making me wonder.

As for going to uni and changing careers Jean, I would dearly love to do that but unfortunately atm money is my biggest hurdle. The costs for uni to obtain a degree then a masters is out of my price range until i pay this house off.

Thanks for the replies folks and i will be looking for results of more ceph data in the future.
Keep up the excellent work guys and girls :smile:)

Tony.
 
Joined
Dec 24, 2002
Messages
1,169
Heya!

Well, time to throw my two "scents" in (groan!) :lol: . "Smell" is kind of a relative term here, mostly since taste and smell are chemoreception, and therefore are related. I tend to think of them as pretty much the same underwater, where traditonal definition of smell doesn't quite apply here. Chems in the medium (water) are detected by cephs by a system of chemoreceptors on the suckers. So they do "tastesmell" the water.

An interesting side note: Many molluscs have small patches of sensory epithelium located near the gill or mantle wall called osphradia. These are chemosensory, and perhaps serve in bivalves as a sediment detectors. However, the only ceph with osphradia is Nautilus. I would theorize that the suckers of cephs are so specialized that osphradia would be unecessary.

Oh well... Sorry if this is a confusing post. Its late, and I can't sleep, so I decided to post. I'm wierd that way...

"Aye, breach thy last to the sun Moby Squid!"

Sushi and Sake (and Hello Panda! crackers),

John
 
Top