Friday Squid Blogging: Dissecting a Giant Squid

In Santa Barbara.

Among other dissection highlights, Hochberg pulled out plastic-like pieces, which comprised what could be best described as a backbone, as well as a translucent brownish-yellow piece of the beak, which is made of fingernail-like material. The giant squid’s anatomy features a mouth at the top of the head, which means the esophagus travels through the brain. “So you have to get very small chunks of food,” said Hochberg, “or you’ll blow your brains out.” The sharp beaks, then, are used to chomp food into tiny pieces before sending it down the esophagus, through the brain, and into the gut.

Posted on September 19, 2008 at 4:56 PM13 Comments


Peter E Retep September 19, 2008 6:53 PM

When I was a kid, I was taught Ontogeny Repeats Phylogeny, which led to many spectacular misconceptions, including the idea that embryo starts out as a lower order invertebrate, becomes a coelate like squid, repeats a gill creature stage, and slowly retraces evolution through gestation through amphibian, reptillian, to animal, and ultimately human form.

Genetic Code has now resolutely lain this false assumption to rest.
Taxanomic Speciation by structural differences may rest on a similarly slippery slope, also to be pushed over the edge by DNA realities.
(I refer to “As a taxonomist, Hochberg is hoping that this squid’s samples will shed light on whether California’s populations are the same species as the ones in Japan and others than show up as far south as Hawaii.” )

Currently speciation is decided by gene matrix (DNA code), by color phase, be behavior, and even by politics. [The Endangered Species Act’s “identifiable and distinguishable population in an identified region” which led to the spotted [recessive] feather phase of the barred owl being declared an endangered species, and, by some reports, shutting down the northwest timber industry.]

Under these criteria, sometimes a dalmation is a different species from a [Beverly Hills] chihuahua, and sometimes it’s only a breed difference.

To rely on taxonony to speciate when we have DNA testing available seems so last millenium. Just ask the tiglons and the grolars.

Carlo Graziani September 19, 2008 9:58 PM

“…Hochberg pulled out plastic-like pieces, which comprised what could be best described as a backbone…”

If you wish to see a minature version of what (I think) this is describing, go get a whole squid from your local seafood retailer. Pull the tentacles away from the body, together with the attached head and internal organs. The body — a hollow cone — is stiffened by a translucent, feather-shaped bit of cartilage that looks for all the world like a piece of transparent plastic. You can reach in and gently pull it out, and wonder.

Then make calamari.

Clive Robinson September 19, 2008 11:57 PM

“which means the esophagus travels through the brain.”

Ouch, and I thought heart burn was bad enough….

2esophagus September 21, 2008 7:18 PM

‘…small chunks of food…or you’ll blow your brains out.’ < replace food with truth, how truth is handled, just like boiling a frog, about as pleasant as dissecting a giant squid as well.
In recent news migration to New Zealand is really picking up.

FNORD September 21, 2008 9:49 PM

@Peter E Retep:
Reality doesn’t nicely follow species boundaries anyway. You may end up with slight cline between/within (a) species. In it’s most simple form, you have populations A, B, and C along a cline. Each can breed within itself (obviously), and B can breed with both A and B, but A and C do not produce fertile offspring. How do you assign the populations into species?

Peter E Retep September 22, 2008 5:29 PM

Good point.

By the way, has this ever been observed above the level of invertebrates?

I know about the cypress cross Mediterranean species appropriation by pollen, but that only approximates the example.
(And of course there is the recessive seedless varieties of fruits, but that hardly counts.)

Davi Ottenheimer September 22, 2008 7:24 PM

Strange, why not put the brain more out of the way? What’s the advantage of a supra-esophageal doughnut-shaped brain for invertebrates? It does not seem like a very intelligent design.

Peter E Retep September 26, 2008 7:26 PM

@ Davi Ottenheimer

It does not seem like a very intelligent design.

Maybe it’s the best the squids could do = = 😉

Daniel C February 5, 2009 8:58 AM

Has a squid ever actually damaged its brains by ingesting something too large, or does it always break up its food well enough?

It would seem that if the brain damage thing were a frequent occurrence, this design would not have lasted very long. It is possible that the beaks are sufficiently well designed to make the redesign of the brain unnecessary.

It makes no more sense to disparage the design of the squid from an evolutionary perspective than from an ID perspective. The distinction between evolution and ID is not whether designs are good or bad – it’s pretty obvious that biological organisms are elegantly designed. It’s whether such design can be accounted for by spontaneous natural processes.

J May 14, 2011 11:58 PM

@ Daniel C

Nicely stated.

Evolution requires the design works. If any working reason for this layout is later found, it’ll be easily hijacked by evolution and/or too subtle for the public to understand/care about, this argument will be dropped, and we’ll all just move to something else we don’t understand, just like with the vertebrate eye.

Evolution cannot be falsified outside of hard probabilistic analysis, and hardly anyone cares to speak of that.

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