News Article on Giant Squid Reproduction

tonmo

Titanites
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#1

CapnNemo

Vampyroteuthis
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#2
Very interesting stuff there. Do we have any more information on that series of strandings?

"For many years the race has been on to try to film a giant squid going about its business in the ocean depths, and many marine scientists are vying to get the first video footage. So far all expeditions have been unsuccessful, but a new Spanish expedition is currently being planned and maybe this time we will be lucky."

Exciting stuff. I'm well and truly outside the scientific community, how much do marine scientists know of other teams' plans and efforts. Is there any chance of creating a kind of 'year planner' or 'timetable' of planned expeditions or research? Does such a thing exist?

Sorry if that sounds really naive, I just been watching The Life Aquatic and have just read 'Mapping The Deep' again so my head is filled with visions of marine teams zooming round the world, desperately trying to make headway before funding runs out.
 

monty

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#3
self-insemination or not

It seems like an obvious check to do some quick DNA sequencing, and see if the sperm in the injected packets is a haploid form of the DNA of the male squid they're embedded in-- if so, then he injected himself, if not, the packets came from another male...
 

Jared

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#5
Here is the source for this article. What I find interesting here is their speculation on the cause of the strandings.

Internal examinations shed some light on the mystery, with the discovery that two of the squid had suffered extensive damage to internal muscle fibres and their stomachs were ripped open and their digestive tracts mangled – one animal in particular had probably died from its injuries. The squid had also suffered severe damage to their ears that would have effectively disorientated them. The coincidence was that at the time of both mass strandings, geologists had been running a seismic airgun survey in the vicinity with a line of 10 towed airguns – each capable of firing 200 decibel sound pulses down to the seabed.
While the gay squid / self insemenating squid angle is interesting, I think possibility that seismic surveys are killing squid is a far more important news story.
 

monty

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#6
Jared said:
Here is the source for this article. What I find interesting here is their speculation on the cause of the strandings.



While the gay squid / self insemenating squid angle is interesting, I think possibility that seismic surveys are killing squid is a far more important news story.
The fact that squids don't have ears makes me question the credibility of the whole article, although it's certainly plausible that strong shock waves could hurt squids... I don't know of an authoritative scientific study, but it's mentioned in one of Richard Ellis' books that someone has a theory that sperm whales use a sonar "blast" focused by the big oil-filled cavities in their heads to stun squids before eating them....

I found the idea that someone in Norway had measured the oxygen transport capacity of blood in architeuthis at depth and surface to be intriguing, but it also raises a lot of "skeptic" flags-- it's hard to imagine how they'd measure it at the surface, and I can't come up with even a far-fetched way they could have any idea of what it is at depth. From Dr. Gilly's work on dosidicus described at TonmoCon, it's known to be pretty hard to understand these sorts of physiological issues even when you know how to catch large numbers of healthy animals and observe them in their natural environment. (also, even if the blood's affinity for oxygen went down, there's a lot more oxygen in the water at the surface, so it's not clear to me that this would be fatal for the squid, although it does raise questions of whether the gills are better suited to extracting rare O2 from the water and storing it in the blood as a resrvoir or something like that...)
 

Jared

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#7
The article was published in the newsletter of the International Council for the Exploration of the Sea. They publish a journal as well and seem to be a reputable organization.

It appears that the newsletter is published for a general audience (hence the annoying lack of citations). When they referred to "squid ears", I assumed they were talking about statocysts. According to Roger Hanlon and John Messenger's book on ceph behavior, destruction of these organs causes the type of disorientation referred to in the article. Since these organs affect balance and the detection of sound (at low frequencies), it's understandable why someone might refer to them as ears rather than going through the hassle of explaining what a statocyst is.

I'm also curious oxygen transport statements in the article. I wish their sources were cited. I've got one more year to go on my marine biology degree and I'm afraid I'm not entirely up to speed on the subject of physiology yet so I'll have to leave that to people who know more.

...Steve? ...Roy? ...Gilly? ...Jean? ...others who's names aren't coming to mind?
 

Jared

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#8
Rather than doing the homework I'm supposed to be doing, I allowed myself to be sidetracked buy the questions raised by that newsletter article. I managed to find the journal paper that inspired the newsletter piece.

Records of giant squid in the north-eastern Atlantic, and two records of male Architeuthis sp off the Iberian Peninsula
GUERRA A, GONZALEZ AE, DAWE EG, et al.
JOURNAL OF THE MARINE BIOLOGICAL ASSOCIATION OF THE UNITED KINGDOM
84 (2): 427-431 APR 2004

That paper cites a letter to Nature regarding the oxygen binding capability of Architeuthis blood. The letter is by Ole Brix of Norway and it's from volume 303 published in June of 1983. The gist of it is that blood was taken from a giant squid that had been dead for two days and the oxygen binding properties of the blood were tested at different temperatures. Apparently, their blood doesn't work very well at higher temperatures. I think I'll need to take BioChem before I actually understand the entire letter though.

The cool thing about the article is that it says the squid was actually alive at the time of capture and that it was hooked in small bay that was about 15 feet deep!
 

monty

Colossal Squid
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#9
Jared said:
Rather than doing the homework I'm supposed to be doing, I allowed myself to be sidetracked buy the questions raised by that newsletter article. I managed to find the journal paper that inspired the newsletter piece.

Records of giant squid in the north-eastern Atlantic, and two records of male Architeuthis sp off the Iberian Peninsula
GUERRA A, GONZALEZ AE, DAWE EG, et al.
JOURNAL OF THE MARINE BIOLOGICAL ASSOCIATION OF THE UNITED KINGDOM
84 (2): 427-431 APR 2004

That paper cites a letter to Nature regarding the oxygen binding capability of Architeuthis blood. The letter is by Ole Brix of Norway and it's from volume 303 published in June of 1983. The gist of it is that blood was taken from a giant squid that had been dead for two days and the oxygen binding properties of the blood were tested at different temperatures. Apparently, their blood doesn't work very well at higher temperatures. I think I'll need to take BioChem before I actually understand the entire letter though.

The cool thing about the article is that it says the squid was actually alive at the time of capture and that it was hooked in small bay that was about 15 feet deep!

That's really interesting; I'll have to look those up sometime soon!
 

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