Sep 23 2011

Friday Cephalopod: Blue is beautiful

Categories:

Cephalopods, Organisms

by PZ Myers

(Also on Sb)

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25 comments

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1

Aquaria

23 September 2011 at 5:03 pm (UTC -5) Link to this comment

What a beauty! I could look at her all day.
2

Glen Davidson

23 September 2011 at 5:03 pm (UTC -5) Link to this comment

Blue — rings means “Get thee gone.” They do look vaguely like infected skin lesions, IMO.

Still, why must venom-bearers look so attractive?

Glen Davidson
3

Robin Raianiemi

23 September 2011 at 5:04 pm (UTC -5) Link to this comment

I think I’m in love.
4

James Emery

23 September 2011 at 5:05 pm (UTC -5) Link to this comment

Blue means, “You’re freakin’ dead, mate” ;)
5

ritebrother

23 September 2011 at 5:08 pm (UTC -5) Link to this comment

These awesome Friday Cephalopod pics do rotation as my desktop. Thank, PZ!
6

Dhorvath, OM

23 September 2011 at 5:23 pm (UTC -5) Link to this comment

Magnificent!
7

fastlane

23 September 2011 at 5:29 pm (UTC -5) Link to this comment

Gorgeous! I remember the first time I saw one of these in a shallow reef off the coast of Okinawa. I didn’t stick around to get too close of a look once I saw the rings.

My 8th grade science teacher (in Okinawa) was a marine biologist with 14-15 30 gallon saltwater aquariums in the room. She used to take us on field trips to some of the local beaches about once a month. She liked to relate the story of the blue ring that some students had captured, but apparently, it never got irritated enough to display until she had it in a aquarium for several weeks! Could have been a story to scare us into being more careful, but I have no real reason to doubt her.
8

joed

23 September 2011 at 5:59 pm (UTC -5) Link to this comment

how is this animal venomous?
touch
bite
spray like a cobra?
certain death?!
9

Foolish-Rain

23 September 2011 at 6:01 pm (UTC -5) Link to this comment

No-no words. No words to describe it. Poetry! They should’ve sent a poet. So beautiful. So beautiful… I had no idea.
10

joed

23 September 2011 at 6:03 pm (UTC -5) Link to this comment

it look like a piece of jewlry
a pendant worn round the neck
made of siver and turquoise
inlaid in the finest egypt alabaster
11

ChasCPeterson

23 September 2011 at 6:15 pm (UTC -5) Link to this comment

how is this animal venomous?

Bite. In its salivary glands are bacteria that produce tetrodotoxin. And that’s nasty stuff. It blocks the sodium channels that produce neuron action potentials. The muscles we breathe with require action potentials to cause them to contract.
Not certain death, but almost.
12

Luke Scientiae

23 September 2011 at 6:29 pm (UTC -5) Link to this comment

I remember a hypothesis that brightly colored Amazonian frogs had bright colors to ward off predators; the bright color was supposed to be an indicator of how nasty the consequences of messing with the frog could be.

Is there an anologous thing cephalopods? Are the intensities of their colors roughly correlated with how poisonous they are? How general is that in the animal kingdom, anyway? And, do cephalopods have color vision?

Thanks in advance.
13

Glen Davidson

23 September 2011 at 6:45 pm (UTC -5) Link to this comment

And, do cephalopods have color vision?

The general answer is “no,” but I thought I’d better check, and it’s said that the only cephalopod known to have color vision (or at least more than monochromatic color) is the firefly squid. Many haven’t been checked for it, though. Three pigments for the firefly squid.

Still, many–or all?–cephalopods can see polarized light, so if most are lacking in one sort of vision, they have other visual abilities that most vertebrates, including ourselves, lack.

I believe it’s assumed that venomous or poisonous animals in the sea also often advertise the fact through striking visual effects, including color. Still, isn’t that something that’s largely a surmise for any animal? It’s difficult to test, but seems to make sense. Still, humans seem not to have much innate sense of it themselves, so do other animals? Or, supposing that it is true, do they have to learn that.

Glen Davidson
14

ChasCPeterson

23 September 2011 at 6:52 pm (UTC -5) Link to this comment

bright colors to ward off predators; the bright color was supposed to be an indicator of how nasty the consequences of messing with the frog could be.

aposematism
15

Snoof

23 September 2011 at 6:53 pm (UTC -5) Link to this comment

Is there an anologous thing cephalopods?

Possibly. Blue-Ringed Octopus don’t actually have the rings all the time; they generally show up when the octopus is stressed, so it’s quite possibly some kind of warning display.
16

daveau

23 September 2011 at 7:00 pm (UTC -5) Link to this comment

It looks like a baby blanket. A beautiful, beautiful, poisonous baby blanket. Yay, Friday!
17

captainahags

23 September 2011 at 7:05 pm (UTC -5) Link to this comment

I used to have this computer program called Dangerous Creatures back in the Windows 97 days, when I was a youngun. . . these little guys were in it. I never realized quite how small they were until much later though, when I saw Steve Irwin catching one. Quite a wallop, and a gorgeous color scheme to boot! IIRC, it’s not 100% lethal in that it’s not the venom itself that kills you, but the suffocation (if that makes any sense at all) so if they get you into an iron lung fast enough you can survive until the poison makes it out of your system. I seem to remember something like this in one of the Michael Crichton books- the bad guys had blue ringed octopi(uses?) and they would put them in sandwich baggies and then agitate them while putting them on the protagonists. . . Or something like that.
18

David Marjanović, OM

23 September 2011 at 7:08 pm (UTC -5) Link to this comment

do cephalopods have color vision?

Isn’t it more important whether vertebrates (…”fish”) have color vision? Because they do. Most that aren’t mammals even have 4 different color receptors, not just 3 like Old World monkeys.
19

Brownian

23 September 2011 at 8:06 pm (UTC -5) Link to this comment

it’s said that the only cephalopod known to have color vision (or at least more than monochromatic color) is the firefly squid. Many haven’t been checked for it, though.

I blame lack of funding for schools.
20

otrame

23 September 2011 at 8:49 pm (UTC -5) Link to this comment

Brownian, I want to have your children.

Of course I am old, fat, and ugly, but the impulse is still there.
21

andrewv69

23 September 2011 at 10:23 pm (UTC -5) Link to this comment

@Dhorvath, OM

There you are! As I recall you were one of the very few, apparently willing to engage me in an honest exchange of viewpoints and without any apparent ulterior motives. So when I came across this cartoon awhile ago, I thought that perhaps you may appreciate it: In which we betray our gender
BTW Gabby also has art for sale if you are so inclined.Note: I do not know the artist personally, and I have no financial interest, or profit in any way from any sales made.
22

axewaquestion

24 September 2011 at 12:56 am (UTC -5) Link to this comment

That is one amazing animal.
23

DingoDave

24 September 2011 at 1:42 am (UTC -5) Link to this comment

Small, but deadly.
Where I live they’re not uncommon, and I have advised my young son not to touch any octopus/i he might encounter in any tidal pool around here.
24

Agi

24 September 2011 at 5:46 pm (UTC -5) Link to this comment

Beaut tnings,
more’s the pity you have to actively annoy them to go blue ringed and its just short of them biting and possibly nearly not killing you.
25

Gyeong Hwa

25 September 2011 at 5:38 am (UTC -5) Link to this comment

Beautiful and deadly,
Kinda like the oleander flower.