Colossal Squid Necropsy

Clem

Architeuthis
Registered
Joined
Apr 6, 2003
Messages
1,839
Reaction score
49
Steve O'Shea;8683 said:
Cranchiid squid like Teuthowenia can pull their head entirely within their mantle, inking within the mantle and appearing like grapes (this is actually what I thought we had in one sample several years ago - deep-sea 'grapes'). As the eyes of Mesonychoteuthis have photophores, perhaps this animal can also withdraw the head (and arms) within the mantle ... ouch ... and the black lining of the mantle wall conceals any bioluminescence from the eyes. You still have to have a large-enough predator to warrant this behaviour, however. Perhaps the smaller animals need to be able to do so, and the character state is just carried forth through to the adult (where it isn't really required, but is a non-lethal behavioural attribute ... as in it doesn't harm the animal to be able to do so, rather than it being advantageous to be able to do so).
...elsewhere in the forums ob brought up the 1981 Meso specimen caught by a Russian trawl. We were discussing Mesonychoteuthis eyes. The '81 squid's eyes look very well-preserved...which is amazing, when you consider that the squid was trawled. The mantle and arms look as banged-up as you'd expect, but the visible portion of the head hasn't suffered nearly so much abuse. Trying to account for the high level of preservation of the most delicate parts, I recalled Steve's earlier post. The photo of the '81 Meso suggests to me that large sub-adults are capable of retracting the head into the mantle cavity, and that's what this squid did when the trawl hit it.

Thoughts?

Clem
 

Attachments

Joined
Feb 5, 2003
Messages
373
Reaction score
7
cuttlegirl;88872 said:
Hmmmm... which might explain why the head looks so much smaller than the mantle, because it has to fit inside the mantle.
I agree. And looking at this photo with the latest discovery in mind, the head does look quite smaller than the mantle. I never really noticed that before.
Interesting stuff!
 

ubiquity

Blue Ring
Registered
Joined
Apr 16, 2003
Messages
46
Reaction score
0
rather interresting stuff here. something that kept occurring to me was that the reason for "cloaking capability" might well be courtship related,and that rather than some fearsome as of yet unknown predator the culprit was more likely members of it's own species. just a thought.
 

ubiquity

Blue Ring
Registered
Joined
Apr 16, 2003
Messages
46
Reaction score
0
in the case of it being a courtship related issue,what i'm getting at is the possibility of rival males needing to escape one another when they are outmatched.

but something else occured to me while researching humboldts the other day...cannibalism. don't know if there's been any evidence in the stomachs of necropsied messies,but i'd run across an artice out there somewhere stating that in 1999 a tasmanian archi turned up with tentacle fragments in it's belly.

just shooting in the dark here.
thought i'd share and all that.
 

Clem

Architeuthis
Registered
Joined
Apr 6, 2003
Messages
1,839
Reaction score
49
ubiquity;89053 said:
in the case of it being a courtship related issue,what i'm getting at is the possibility of rival males needing to escape one another when they are outmatched.
Hi Ubiquity,

That makes sense if the mantle of the cranchiid in question is transparent/translucent at the age of sexual maturity, and we do see that feature in smaller cranch squid. A grown Mesonychoteuthis's mantle is thick and opaque, and has a black-stained inner lining to boot, so inking inside itself may not have an appreciable benefit. It would be beneficial in the early stages of Meso's life, when it is more clear-bodied and vulnerable to a wider variety of would-be predators, including other squid. But, maybe I've been making an assumption about the self-inking being deliberate in the first place. Is it possible that it's involuntary, a consequence of the squid turning itself into a ball?

Cheers,
Clem
 

ubiquity

Blue Ring
Registered
Joined
Apr 16, 2003
Messages
46
Reaction score
0
howdy clem! :smile:

involuntary?

you really think so?
...what's leading you to this conclusion?

and by the by it's good to be back. haven't had a chance to keep up with you guys in quite some time.
 

Steve O'Shea

TONMO Supporter
Registered
Joined
Nov 19, 2002
Messages
4,671
Reaction score
27
ubiquity;89053 said:
but something else occured to me while researching humboldts the other day...cannibalism. don't know if there's been any evidence in the stomachs of necropsied messies,but i'd run across an artice out there somewhere stating that in 1999 a tasmanian archi turned up with tentacle fragments in it's belly.
Hi Ubiquity. We put a paper out on this very thing in 2004 (NZ Journal of Zoology I recall). There's a version of it online here, although I do note some corruption in some of the characters (if you want a pdf of the paper just pm me). The Zeidler & Gowlett-Holmes paper to which you refer (from Tasmania) didn't attribute the sucker rings in the stomach caecum of Architeuthis as belonging to Architeuthis, but they were certainly of a size consistent with them. There has been a further, more recent paper recording cannibalism in Architeuthis, based on genetic screening of stomach contents, so it doesn't appear to be too infrequent in occurence.
 

OB

Colossal Squid
Staff member
Moderator
Joined
Oct 19, 2003
Messages
3,097
Reaction score
52
I'm afraid I can't chime in with regards to Russian trawl Meso's headsize, it's actually just slightly smaller than the mantle opening, but there's a notable "constriction" between the massive eyes and the posterior portion of the head.

Was this specimen's ML determined at all?
 

ubiquity

Blue Ring
Registered
Joined
Apr 16, 2003
Messages
46
Reaction score
0
thanks for the link steve!
a good read for sure and very informative.

needless to say it has my wheels spinning.
so,..
any evidence of cannibalism in messies yet?
 

Members online

No members online now.

Latest Posts

Forum statistics

Threads
20,346
Messages
204,920
Members
8,485
Latest member
Bee_bee

Monty Awards

TONMOCON IV (2011): Terri
TONMOCON V (2013): Jean
TONMOCON VI (2015): Taollan
TONMOCON VII (2018): ekocak

Top