Squid beak variation (and stuff)

[Steve O'Shea]

Kat has sent me pics of the type specimen of Mesonychoteuthis (the one that Robson himself based the description of the species on - WOW!), and of the beaks, but I don't want to post them online yet because she should do that (don't want to do anything that might jeopardise me ever getting my Neil newspaper clipping back ). It's way cool to see it, after all of this time!

I can't believe that you were with her there at the BM, behind the scenes (where few ever get to go), and that thing was sitting in a tub behind you and you didn't see it I'll just have to come over one of these days, have a few beers, then go take a peek at it together.

 

[Steve O'Shea]

Well, bit of a buzz for me. Was sorting through the contents of whale # 10, actually the first stomach I received years ago (the one with all of the Mesonychoteuthis beaks in it, and the heavily scored hide), a male that stranded several years ago on the East Coast of NZ (rather than the West, where all of 1-9 have stranded over the past year).

One of the very last beaks I extracted was a minute/juvenile Architeuthis, with a lower rostral length (LRL) of 4.5mm. To give you some indication of scale I have placed it next to a mature female lower beak of LRL 18mm, and to a sharpened pencil lead.

Malcolm Clarke has earlier reported juvenile Architeuthis in the stomachs of whales caught off Durban (left hand figure, below); I've put a heavy black dot on the axis where the New Zealand and Durban specimens sit on the graphs. I've not encountered one before, so that's kind-of made my last two years!

It is very significant that the juvenile occurs in waters near New Zealand (we've only ever had the paralarvae and adults from these waters); it is also significant that the juvenile Architeuthis has not been identified amongst any stomach sample from the West Coast thus far (though I haven't finished yet).

 

[Steve O'Shea]

One of the most difficult beaks to identify are those of cranchiid squid (Cranchiidae). As there are few illustrations of beaks of these beasts out there I've put a few online here.

This first composite is of Megalocranchia sp., the lower beak from a specimen received late last year from the stomach of a blue shark off northeastern New Zealand. The lower image is a comparison of beaks - the dark, left-hand and incomplete beak taken from the stomach of sperm whale # 10.

And the animal from which this beak came:

Even though this squid was in a pretty bad way (digested and incomplete), the beaks prove invaluable for identification of other samples from whale stomachs. I haven't attached a species name to this animal - it is not a very well known genus, and adults are extremely rare in collections.

 

[Steve O'Shea]

I couldn't help myself - they're just so exquisite. Here are a couple of plates of Mesonychoteuthis hamiltoni beaks throughout their ontogenetic range, all taken from the stomach of Whale # 10.

The juvenile and subadult beaks are all quite brown, the greatest majority lacking wings (these develop at greater rostral length/mantle length).

Larger beaks are quite dark, black, and extensively eroded ...

 

[Steve O'Shea]

You'll not find images like these anywhere else online - they're a TONMO exclusive!

.... even the broken pieces are exquisite