Good Vibrations

[Fujisawas Sake]

Second major ceph question for the week:

Most marine animals have a sense of vibrational detections. Fish have lateral lines, marine mammals can hear, etc. Now, given that squid are pretty much the molluscan evolutionary equivalent of fish, do they have a sense of "sound" (vibration) detection? Any sign of organs designed for this purpose?

Sushi and Sake,

John

 

[WhiteKiboko]

i think this was somewhat addressed earlier in the year (though i do recognize that was a LONG time ago).... someone who was involved or at the least had been out on squid boats off CA, described tossing 'Seal bombs' (essentially oversized fireworks) to scare away the seals before hauling in the squid.... so in my uneducated opinion, id have to say no with a 'but'.... if you don't like that, i might be persuaded to change it to a yes with an 'if'.....

of course i encourage truly knowledgable people to chime in....

 

[andermuffins]

I've whipped out my copy of Cephalopod Behaviour by Hanlon and Messenger and the bookmark happened to be on the 'Lateral Line Analog' page. They say that at least nine genera of cephs distributed among the Sepioidea, Teuthoidea andOctopoda have lines of hair cells along their arms and on their heads. Here's the central sentence or so (referring to cuttlefish):

They contain many thousands of hair cells, and physiological studies have shown that these respond to sinusoidal water movements within tthe 0.5--400 Hz range (Bleckmann, Budelmann and Bullock, 1991). The most effective frequencies are between 75 and 100 Hz, with the minimum threshold and 0.06 μm peak-to-peak water displacement at the level of the receptor cells.

I recall them mentioning these lateral line analogs in several other parts of the book, but it's late and I'm not going to try to find them.

--
Mark

 

[Fujisawas Sake]

Mark,

Sounds good. BTW, where did you get that book?

WK,

Yeah, I've also heard of Seal Bombs, but I wasn't aware of how they were used exactly. Thanks for the info.

Happy Gnu Year everybody!

John

 

[andermuffins]

John,

The book was a birthday present. I think my sweetie found it at the Barnes & Noble here in Berkeley. BN has it available on its website for about forty bucks U.S. for the ~200 page paperback. Not cheap, but it's a good, dense book. Judging by many of your posts you've advanced somewhat farther in biology studies than I have, so I can't say how much new material there would be for you but to me it's a great reference and is reasonably well-written and full of great ceph stuff. It's focuses on behaviour, but it gives a good physiological and ecological background as well.

Here's the full info about the book if you want to try to find it a bit cheaper somewhere.

Cephalopod Behaviour
Roger T. Hanlon & John B. Messenger
Cambridge University Press, Cambridge. 1996
ISBN: 0 521 42083 0 hardcover
ISBN: 0 521 64583 2 paperback

--
Mark

 

[Fujisawas Sake]

Mark,

Wow... You actually read some of my posts? I wrote most of them while drunk on sake so I didn't think they were coherent.

Seriously though, its always good to hear from another Bio student. I'm a few notched away from a degree in Marine Bio/Zoology, with (hopefully) a Psychology minor.

Gee... what really blows is that cephalopod books are hard to find and expensive as hell. My invert zoology book was nearly $200! Crickey!

Thanks for the info!

Sushi and Nigori Sake,

John

 

[Tintenfisch]

Here's another reference - same guys, earlier paper.

Budelmann, B.U.; Bleckman, H. 1988. A lateral line analogue in cephalopods: water waves generate microphonic potentials in the epidermal head lines of Sepia and Loligunculap. Journal of Comparative Physiology A 164: 1–5.

 

[andermuffins]

John,

While I'm sure it is nice to hear from other Bio students I must admit that I have inadvertently mislead you. I am a *shudder* Chemistry student aiming for Chem. Oceanography in some future degree. You know, learning how to poison cephalopods en masse.

Basically I prefer to play with fire and acids rather than do too many dissections or vivisections. Critters are just too gooey inside for me, but I'm glad someone (else) studies these important things.

Textbooks *are* frightfully expensive. I haven't had a single text cost over about $140 U.S. so far, but books for any given class can easily break $200. Fortunately one can makes hundreds or even thousands of dollars every year in the environmental sciences.

--
Mark

 

[Fujisawas Sake]

Thank you Kat (or should I say "Jonah"?)

Mark,

I liked chemistry, and while the subject was always conceptually easy for me, the actual classes kicked my butt. The very fact that you would major in it is impressive.

As far as dissection goes, I hate it. I prefer my animals alive and (preferrably) in their natural environs. That being said, I am a huge fan of the Monterey Bay Aquarium and similar research institutes even though such places keep animals in captivity. I feel that anything you can do to bring something like that to the people is worth its weight in gold-pressed latinum (yes, I am also a part-time Star Trek nerd.. so sue me).

I remember a chemist named Bassam Shakashiri at the U. of Wisconsin, Madison. He has a fun series of great chemistry experiements that are entertaining and educational. Look him up sometimes, or at least his work.

Sushi and Ginjo,

John

 

[andermuffins]

John,

I too receive the odd butt-whomping from a chemistry class. The subject, while genuinely somewhat difficult, is unfortunately used to 'weed out' 'undesirable' students from the sciences in many Universities (at least in the USA).


It seems to me that it is desirable to interest more people in the sciences (cephalopods!) rather than try to push them out. Biology, chemistry, toxicology &c. play such important roles in the modern world that it's insane to think that many nations could have a reasonably 'informed electorate/populace' if we try to show people that the sciences are too hard and they just shouldn't try to study them at all. Not that they aren't hard, they're just worth the effort, even if it's not one's full-time career.


I actually visited the Monterey Bay Aquarium for the first time a month or so ago even though I've lived only a few hours away for the whole time they've been around. I like the 2 or three really huge tanks they have there for the kelp bed exhibit and the pelagic fishies. The little tanks with big animals like the Enteroctopus dofleini in them tend to depress me a bit. Nonetheless they do seem to be addressing my rant above by showing this groovy stuff off to the public.

The 'science communicator' folks there do seem to light up a bit when they find out they're talking to an adult who wants to study oceanography. They get all chatty about what schools they went to and where and what to study.


Mushroom broccoli stir-fry and IPA

 

[um...]

It seems to me that it is desirable to interest more people in the sciences (cephalopods!) rather than try to push them out. Biology, chemistry, toxicology &c. play such important roles in the modern world that it's insane to think that many nations could have a reasonably 'informed electorate/populace' if we try to show people that the sciences are too hard and they just shouldn't try to study them at all. Not that they aren't hard, they're just worth the effort, even if it's not one's full-time career.

Bravo! Well stated, indeed.

Mushroom broccoli stir-fry and IPA

Bravo! Well sated, indeed.

 

[Jared]

I have the same Cephalopod Behaviour book that andermuffins mentioned. In the section just before the stuff about the lateral line analogs, they discuss the role of the statocysts in sensitivity to sound. The main functions of the statocysts are sensing orientation and acceleration but also (according to the text):

"Only recently has it been shown unequivocally that cephalopods are quite sensitive to low-frequency vibrations."

Apparently there was a study (Packard, Karlsen, & Sand 1990) where Sepia, Loligo, and Octopus were trained to respond to sound and they responded well to frequencies below 10 Hz.

As for the "seal bombs", I'd imagine that the squid were aware of the explosions but they just didn't care. Those squid only seem to have one thing on their little minds when they're mating. I've been diving and seen a Loligo extruding her egg case. I got right up in front of her (within inches) and she just kept on about her business. I've also seen video of sharks cruising through the crowd of spawning squid chewing up as many as they can fit in their mouths. The squid don't even try to run away because they're busy.[/i]