Scaled reference drawings of architeuthis?

[CarlS]

Hi again Steve :)
Here are some questions pertaining to the images you posted in this thread.

I was expecting to see the arms more symmetrical about their radial axis.
In the book by Ellis, a roughly triangular arm cross section was mentioned, with some flatening on the oral face. Is this description consistant with what you have seen?

Related to the above question, is the cross-sectional shape of an arm roughly constant throughout the arm's length, or does it become more symmetrical with distance from the base?

Does the cross-sectional shape of the tentacles become more cylindrical a short distance from the arm crown?
Also, is there noticable flattening along the oral surface where the tentacle's "clip" together?

The buccal membrane appears to be very loose and almost baggy.
Has it just relaxed post-mortem, or did it have this looseness when the animal was alive?

How large is the beak with respect to the arm crown width?

Is the buccal lappet a thickening in the buccal connective where it merges with the membrane around the beak?

Is the buccal bulb visible behind the buccal membrane, or does it just provide underlying shape and support?

I'm under the impression that the buccal connectives and lappets in a ring around the beak, and originating from each arm, would have an appearance like a rather baggy eight armed starfish.
Is this correct, or am I off the mark here?

Thanks again for all your time and effort on this, 8)
--Carl

[Steve O'Shea]

Hi again Steve :)
I was expecting to see the arms more symmetrical about their radial axis.
In the book by Ellis, a roughly triangular arm cross section was mentioned, with some flatening on the oral face. Is this description consistant with what you have seen?

Definite flattening of the oral face, but the cosss-sectional shape of the arms is quite variable, depending on the arm; I'd be reluctant to say that they were triangular, or universally triangular. This is something we'll have to look at later on [next month].

When Richard wrote that book he had never seen the fresh animal; the jacket picture of him holding the Architeuthis tentacle club is ctually a photo taken after the book was completed, in New York, and is the specimen I took over for the AMNH. It is likely that reference to arm shape was taken from a NIWA memoir by Ellen Forch.

Does the cross-sectional shape of the tentacles become more cylindrical a short distance from the arm crown?
Also, is there noticable flattening along the oral surface where the tentacle's "clip" together?

The oral face of the tentacles actually flattens, and the surface is covered with tiny bumbs, giving it a rough texture [that assists in their clasping]; there are also the alternating series of knobs and suckers, that further locks the two tentacles together - these are distributed on the flattened oral face of the tentacles. I'll post a few more pics shortly (couple of weeks).

1) The buccal membrane appears to be very loose and almost baggy. Has it just relaxed post-mortem, or did it have this looseness when the animal was alive?

2) Is the buccal lappet a thickening in the buccal connective where it merges with the membrane around the beak?

3) Is the buccal bulb visible behind the buccal membrane, or does it just provide underlying shape and support?

Re 1), very loose and baggy is norm; I've pics of this structure live in Histioteuthis; will post these later today.

2) Yes

3) For the sake of this, I'd say that it provides underlying shape and support; it is visible orally but not laterally.

I'm under the impression that the buccal connectives and lappets in a ring around the beak, and originating from each arm, would have an appearance like a rather baggy eight armed starfish.
Is this correct, or am I off the mark here?

Picture an octopus mouth/oral region. There is no buccal membrane and no connectives top each of the arms. Picture the same for a squid, then shove an open umbrella inside the arm crown. The umbrella would flop about everywhere unless it had some lateral support - and that's what the connectives do (just cut a hole in the middle of the umbrella to accommodate the beaks).

The query re beak size, will address that one with fresh material; will augment this post with a few other images when at work later today.
Toodles
O

[CarlS]

Thanks for the information here Steve, I'm looking forward to seeing the images you mentioned. :)

--Carl

[Steve O'Shea]

Here are a few of the beaks, extracted

[Steve O'Shea]

.... and the upper beak

[Steve O'Shea]

These are of juvenile Moroteuthis (ML ~ 15mm), taken beneath a microscope (very difficult to focus on a moving animal this small, beneath a scope).

It'll give you some indication what the buccal membrane/beaks are doing, and how far they protrude from the arms of the animal.

Moroteuthis and Architeuthis are VERY similar beasts (if you forget about the adult hooks on the tentacles, and warty skin of Moroteuthis).

[Jean]

Nice shots Steve, can I ask what scope you're using? Mag? Camera?

J

[Steve O'Shea]

Here's a few of larval Nototodarus (the rhynchoteuthis stage ... a true larva, rather than paralarve for the majority of other squid and octopus); although you can't see the beaks/buccal membrane on tehse, they might be of greater interest to you Jean (am posting them here rather than starting a new thread).

I've long-since forgotten the camera specs, but there are so many systems on the market now that this sort of image could be obtained by the majority (you just want to limit the objective lens to 0.32-1x).

The entire larval Nototodarus (probably 5-6mm TL)


Close up of head of larval Nototodarus

Close up of fused tentacles (proboscis)

[CarlS]

Terrific shots and very helpful, thanks Steve :)

The multiple views of the beak with the ruler are just what I needed. 8)

If I’m interpreting the images of Moroteuthis correctly, it looks like the lower beak is nearly transparent and the buccal membrane is extending beyond the beak tip on the ventral side?

--Carl

[Jean]

FANTASTIC!!!! I'm soooooo jealous! I assume they're gouldi I WANT some!!!


J

[Steve O'Shea]

If I’m interpreting the images of Moroteuthis correctly, it looks like the lower beak is nearly transparent and the buccal membrane is extending beyond the beak tip on the ventral side?

It's subject to some interpretation Carl; indeed the beaks of paralarval forms are nearly transparent (the hood darkens first), and on the earlier images are probably surrounded by the buccal lips rather than buccal membrane; without the exact specimen before me I couldn't say for sure.

This is an even closer image of the beak, lip etc. in paralarval Moroteuthis (I didn't know I had this shot myself ... been dredging through the old files ...); the view is from the lower (ventral) surface; that's the funnel to the left of the image; the ventral arms are quite poorly developed ona paralarva of this size.

This image is the lower beak of a comparably sized Moroteuthis specimen; you can see that the lateral walls are without pigment. This beak is way small .... 1-2 mm or so ... doesn't pay to drink too much coffee when extracting these things!

And this image is quite a neat one of the beaks and buccal membrane of Histioteuthis (violet squid). Unfortunately it is the best I have, and it isn't as good as I once thought it was ... At least the animal is live, so it'll give you an indication of what this structure might look like in Architeuthis.

[Steve O'Shea]

... pre-empting a request for info on squid eyes, here are a few (they are tiny animals; forgive me for exposure and focus problems).

Of these, the Architeuthis eye is most similar to this one (an onychoteuthid, like Moroteuthis).

And quite different to this one (of Chiroteuthis), which has a large ventral photophore on the eyeball.

And different again to this one, an enoploteuthid eye, which has series of photophores around the eye.

I've posted them all so as you don't go giving the eye all sorts of human qualities; they're quite different from ours.

[Steve O'Shea]

... and a couple more ...; one of Histioteuthis (upper), the other of a pelagic octopus, Ocythoe tuberculata (lower).

[TPOTH]

Holy. Molly.

*preparing night raid on Master O's conputer to marvel at the amazing pictures*

TPOTH
--ninja skillz

[Steve O'Shea]

....

Preparing coprolite cannon!

I have eyes that see in the dark!

[TPOTH]

....

Preparing coprolite cannon!

I have eyes that see in the dark! I am omnipresent!

...

Dang!

And yet another great idea down the drain...

TPOTH
--fears the barrage of coprolites

[CarlS]

All I can say is great shots, thanks 8)

The extra Moroteuthis image and the Histioteuthis image clarifiy things a lot.

Question:
I imagine the image shows the buccal region of Histioteuthis in a relaxed state.
When feeding, does the beak ever extend beyond the buccal lips and membrane, or does it tend to remain in place within the lips and membrane?

... pre-empting a request for info on squid eyes, here are a few

I guess you saw that one coming

Another question:
If you could apply lines of latitude to the eye globe, with the 90 degree polar latitude at the center of the pupil, at what latitude would the eye globe emerge from the head?
If I get this value too close to the pole, the eye will appear small and flat.
If it's too close to the equator, the poor guy will look like Marty Feldman.


--Carl - up for a minute at 2:30 AM and wasn't expecting anything like this 8) 8) 8)

[CarlS]

Here is a very simplified mockup of the front view of the buccal region of Architeuthis based on the images posted by Dr. O’Shea on the second page of this thread. The arm/tentacle cross-sections are shown as rectangular just to make the placement of the keels and buccal connectives easier to see. The buccal membrane, bulb, and lips are not shown.



The buccal connectives are shown in blue.
The keels are shown in red with the length of the line proportionate to how pronounced the keel appears.

The purpose of the mockup is to make sure I understand how the arrangement of these parts before I start modifying my model. Otherwise, I’m liable to paint myself into a corner on my hard drive.

Questions:
The fourth arm wasn’t shown in the photo set. Are there any pronounced keels on that arm and, if so, where are they located?

Are there any keels missing other than those on the fourth arm?

If anybody has any comments, additions to this, or see something that's just plain wrong, I'd love to hear from them. :)
Thanks in advance for the feedback,
--Carl

[Steve O'Shea]

Just a tad preoccupied right now Carl; could be a day or so before I get around to responding to your queries (and updating arm section 4).
Sorry, O

[Steve O'Shea]

Matt Jones has been so kind as to take pics of the CT-scanned Architeuthis we did several years ago ... that I promised for an eternity that I'd get online.

Some of the pics are not that informative, like this one here, which is of the head region of the squid, but as we progress down the animal and look at everything in section you'll figure out a lot more.

This is just a taste of things to come (the yellow line points to the penis - this being a fully mature male).

The eye lenses are those white structures!!! Will post more on these another day. The dorsal surface of the head is to the right, the ventral to the left. The cavern-like process beneath the head (ventral surface) on these images is a depression into which the funnel sits; the lateral extensions probably envelop the funnel in life.

Now these pics are slightly out of sequence, in that the upper left image of this next block is actually the next image in the sequence from the earlier image upper right block (so you can just see the eye lens disappearing). The original scans are 3 images across, and we've gone for 2 only in the sequences here, to try and preserve as much detail as possible. Sorry for any confusion. We are heading down the head, towards the arms. Soon (next post) we'll get nice images of the arms in cross section (you can just see the two thick ventral arms in the lower left, with the two rather pathetic tentacles at their bases, between the 4th and 3rd ventral arm pairs).