Squid beaks from whale stomachs

Steve O'Shea

TONMO Supporter
Staff member
Nov 19, 2002
Hi all. Tintenfisch and I have just returned from a talk we gave on giant squid, giant octopus and other mysterious denizens of the deep, up country a bit. Whilst at the venue someone from the NZ Department of Conservation gave us a chilli bin of squid beaks (at least a thousand beaks) recently extracted (during autopsy) from the stomach of a stranded sperm whale (of length 13m, or ~ 40 feet). Therein were several (2 at least) giant squid beaks, and at least 4 (we haven't really looked at them in detail yet to give precise counts, and they still smell seriously evil and are covered in parasitic worms) of those belonging to Mesonychoteuthis hamiltoni. Those of Mesonychoteuthis just leave those of Architeuthis for dead in the seriously evil stakes - they're considerably larger and CONSIDERABLY THICKER - almost capable of doing the 'cutting through cable' trick that you'll sometimes read about (with respect to Architeuthis).

In the months to come we'll try and describe a few of these beaks online for you (as a small project), as we try and reconstruct what species this whale had been eating, and where it had been eating them; it is really quite interesting stuff!! We also have the stomach contents of three pygmy sperm whales (Kogia) to examine, so the comparison might be of interest to people here.

Mesonychoteuthis is an Antarctic squid species (none is known from New Zealand waters, or at least none is represented in collections from NZ waters), so the sperm whale, stranding in subtropical waters, was likely feeding quite a bit south of New Zealand. I don't know the cause of death of the sperm whale, whether sick or disoriented, but will let you know as soon we find out.
Steve & Tintenfisch
You said you would try to find out where the whale was eating the squid, I was just wondering, how can you tell location from what you have? It sounds like it is an interesting process, and I just wanted to know what it involved.
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I'll take a crack at this question - don't mind me infringing on your forum, Steve. :wink:

We can figure out which species of squid are normally/have previously been found locally (in NZ waters) - whether throughout their lifetimes or transitorily, during migration - by going through the squid collections in museums here. The upper limits of their size ranges can also be conjectured from the preserved specimens' sizes at various states of maturity; however, specimens recovered from whale stomachs often represent larger animals than those found in the collections, and sometimes come from species for which we have very little comparative material because they are quite rare within the collections. By checking the capture details on preserved specimens, we can then extrapolate where (geographic and depth) and when (time of year) the whale was likely to have eaten a particular size/species of squid.

If we keep a continuous record of all specimens captured in NZ waters, we get a pretty good comprehensive idea of which species are found here, again whether only during certain times of year or more or less always. So when stomachs yield beaks from species not previously recorded locally (e.g. Mesonychoteuthis), even if the whale beached here in NZ, we can be fairly sure (because the museum collections are extensive) that the squid in question was consumed somewhere outside local NZ waters. The literature then tells us where the squid is generally found or where specimens have been previously recorded, and we deduce that the whale has probably been feeding in that general area. In this instance, Mesonychoteuthis hamiltoni is an Antarctic species, so therefore we believe the whale to have been foraging in Antarctic waters - a theory supported by the presence of beaks from other Antarctic squid species in the same stomach. The whale therefore most likely stranded while on a migratory path between the Antarctic and central-eastern NZ.

It is also possible that Mesonychoteuthis does occur locally and has simply never been recorded - in fact, some very surprising squid have turned up here recently - but until we have an actual specimen recorded here independent of a migratory host, we have to exclude it from the known NZ fauna.

Does that help?
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I'm impressed :mrgreen:

For those who might not know, you can often identify a prey item (in this case squid) based on the shape of the beak. Differences in beak shapes, characters, and character states can be subtle, but there is a growing body of literature on the subject to help identify them.

Identifying the natural diet of toothed whale species (by examining the squid diet from stomach contents of stranded dead specimens) has an applied application (in conservation). This is particularly true of rehabilitating stranded whales (the likes of the pygmy sperm whale, such as they do at Mote Marine Laboratory, down Sarasota, Florida). By knowing what squid species are naturally consumed by a whale you can then procure the most appropriate diet for them for rehabilitation. Pygmy sperm whales experience all manner of gastric problems trying to digest squid that are commercially available in the US (and thus available to feed them), so if we can provide the appropriate diet of deep-sea ammoniacal squid (the likes of Histioteuthis, Moroteuthis and Architeuthis) to supplement its diet then rehabilitation will likely be more successful. These squid are normally discarded as trawl bycatch as they have no current commercial value (their ammoniacal tissues render them 'unsuitable' or 'unpalatable' as far as we humans are concerned).

I don't know if anyone has successfully rehabilitated a sperm whale yet, but one day this will be achieved (you'd need an awfully big tank or compound).
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Hmmmmmmmmmmmmm, I could think of nothing better to do on a wet and windy Sunday than be in at work looking at whale stomach contents.

The two Architeuthis were both male at mantle lengths of ~ 1.1m; I've seen many a mature male at this size, with weights ~ 55-75kg. Not exactly huge, but the male only grows to ~ 1.5m ML.

There are at least eight considerably larger beaks attributable to Mesonychoteuthis hamiltoni; seems like the whale had been dining well whilst further south. The beaks look old and quite blackened (as if they've been burnt in a camp fire).

The incidence of Architeuthis beaks in the stomach contents is particularly interesting (both upper and lower beaks of the two being present), as both sets are relatively fresh (although no soft tissues remain). Architeuthis almost certainly migrates into New Zealand waters about this time of the year (but where from is a great mystery), so I wouldn't be too surprised if these two beaks belonged to animals consumed in our waters.

Time to make a prediction: you'll probably start hearing reports (maybe headlines if people are not bored with the squid already, and nothing else is happening in the news) of Architeuthis washing ashore or being caught in fishing nets in about 8 days (15 December) through to Feb (at least).

There are many many many other beaks to identify yet - the story will be really quite interesting.
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Hi Steve,
This tale of stomach contents and squid beaks is fascinating! Please continue to tell us what you are finding as the story unfolds.

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Steve O'Shea said:
There are at least eight considerably larger beaks attributable to Mesonychoteuthis hamiltoni; seems like the whale had been dining well whilst further south. The beaks look old and quite blackened (as if they've been burnt in a camp fire).
Any thoughts as to why these beaks look the way they do? Seems they're remarkable to you, when compared to the others, yes?

Very cool stuff here you two -- thanks!
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Tintenfisch will not be happy with me ... coz I'm having fun ... and she's not here to participate.

Not sure Tony; may be quite old and digested/affected by the whales digestive juices, or they may be naturally blackened like this - I don't have any experience with Mesonychoteuthis beaks when fresh (the adult is a very rare animal in collections, although is supposed to be quite common down there in the Antarctic). All I can tell you is I wouldn't want to be in the water with this thing .... live or dead!

Well, the latest newsworthy item is a beak from our good old friend 'the giant gelatinous octopus' Haliphron atlanticus. Newsworthy because the sperm whale had obviously been feeding in the Antarctic; Haliphron has only recently been recorded from the South Pacific and is considered to be a tropical to subtropical-dwelling species. So where did this beak come from? The Antarctic, Subantarctic or Subtropical New Zealand? Puzzles! The beak is well worn and looks quite old (so, ?not-so-recently eaten).

There's a beak or two (or thousand) amongst that lot that has me scratching my head. Think I'll call it a day there - best go scrub up.
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Steve O'Shea said:
Well, the latest newsworthy item is a beak from our good old friend 'the giant gelatinous octopus' Haliphron atlanticus....
Do you find it interesting that this sperm whale has an octopus (Haliphron atlanticus) in its belly along with all those squid? I've never had much trouble envisioning a whale swooping down into a mass of squid for a hearty meal. But as far as we know, aren't octopus species generally solitary animals?

I guess you just say "a" Haliphron beak, not a bunch. So perhaps he just picked him off, ay? I wonder what other things this sperm whale ate, besides octopus and squid? What does a sperm whale's diet typically consist of? I mean, do they just eat any living thing within their sights, or do they scope out specific prey? I wonder what the likelihood is of one whale dining on such a variety of ceph species, especially the (seemingly?) solitary ones. Or perhaps there are way more of these animals in the ocean than my feeble mind imagines.

Here are some links to the beasties being discussed:

Mesonychoteuthis hamiltoni (note the distribution map)


Haliphron atlanticus (note the in-action video)
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This is all fascinating! I had the dubious pleasure of seeing a Mesonychoteuthis beak myself a couple of months ago at the Natural History Museum in London. It was almost jet black and looked much more robust and powerful than the beak of Architeuthis.

My question is, are there any squid species that are known purely from beak specimens retrieved from Sperm whale stomachs? That is to say, are beaks occasionally found that cannot be classified and may represent undescribed species?
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Absolutely Phil ... there are a few unknowns out there still!

Yes Carol, the beaks probably do digest (certainly the delicate, transparent beak margins have already digested on most of them); otherwise they supposedly are 'purged' from the system, either by vomiting or as # 2's. Having said that, however, if they were 'purged' from the system on a regular basis (supposedly very fast) then what were those Mesonychoteuthis beaks doing in there? I cannot see the whale moving at supersonic speed, from the Antarctic to central-eastern New Zealand in the space of a day or so. Obviously some beaks linger, but just how long they linger is a question I've asked myself repeatedly, and have no answer for. Quite a few Antarctic squid have been recorded from or proximal to New Zealand waters on grounds of beaks identified from stomach contents or regurgitations of these long-distance foraging marine predators (sperm whales and albatross); I don't believe a number of squid so reported from New Zealand occur anywhere near here; two of them in particular, Mesonychoteuthis hamiltoni and Kondakovia longimana (two Antarctic giants), and a third Psychroteuthis glacialis (quite a bit smaller) - all Antarctic dwellers (and there are more that have been reported from NZ waters but are not represented in collections by in situ captured specimens).

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In response to Tony's question(s) I've had to go to my books (I am no sperm whale biologist). I'll digress a bit (some of this might sound a tad gory), because some of what I've tracked down is rather interesting. I'm quoting Clarke, M.R. 1980: Cephalopoda in the diet of sperm whales of the Southern Hemisphere and their bearing on sperm whale biology. Discovery Reports, 37: 1-324.

Re the diet of sperm whales, well, it is almost exclusively squid (and octopus, like Haliphron). Teleosts (fish) and elasmobranchs (sharks, rays etc.), and crustaceans generally account for a very small part of the whales diet. Not all of these large deep-sea squid that the whale eats are likely to form shoals; many may be solitary my nature (but still far more common than net captures would lead us to believe).

A little bit about the sperm whale anatomy, based on a male of 50 feet length, might be of interest to you (Clarke 1980: 49):
"The complete tract measured 215m from the opening of the oesophagus to the anus. The oesophagus (unstretched diameter 28cm and estimated at 2.2m in length) opens into the first almost round stomach (2m outside diameter). The lining of the tongue, oesophagus and first stomach is extremely tough, white in colour and has a network of furrows. To one side there is an opening (25cm diameter) into the second stomach (120cm internal length) which has a smooth soft lining anteriorly becoming longitudinally furrowed in the posterior half. Just in front of the furrowed region an opening (12 x 6cm) connects the second stomach with the narrow tubular third stomach (120cm internal length). This then opens into an expansion of the duodenum by a constricted opening with a strong sphincter. This duodenal ampulla (70cm across) opens into the small intestine which gradually broadens into the large intestine (at a position 180cm from the duodenal ampulla). The walls of the small intestine (13-19cm circumference) and large intestine (27cm circumference) have thin transverse folds (mean depth 1-1.8cm) projecting into the lumen. At a position 24m from the small intestine the large intestine broadens suddenly to form the rectum (1m in circumference and about 4m long).

The way in which the sperm whales use their mouth must be a matter of speculation but the extreme narrowness of the jaw would cause little drag if it were held open during rapid swimming or 'snapping' at cephalopods. The teeth must be used only for holding the prey because fish and squids in the stomach are often nearly undamaged. Presumably squids caught between the front of the jaws at speed are transferred to the back by forward motion of the whale because the tongue lies far back and the lips are not long enough to close the sides of the mouth so that suction generated by swallowing cannot influence food at the front of the mouth. The highly elastic tongue must aid swallowing. The tough lining of the mouth, oesophagus and first stomach is ample protection against the hooks and beaks of a struggling squid. The food is presumably retained in the first stomach until its struggles are over and then it is passed into the second stomach where digestive juices are poured upon it. Break-up of the tissues is greatly facilitated by the large numbers of nematodes (various species of Anisakis) which force their way into all the softer tissues. Mixed with the flesh there are often large numbers of cephalopod beaks and there is little doubt that these also have a macerating effect on the freshly ingested food."

Well, I can't quite reconcile the individual lengths of some of the alimentary structures with the total length of 215m for the digestive tract myself, but that aside, it is an interesting account of the anatomy and possible feeding behaviour of the squid. Thought it might be of interest. In case you didn't know, only the lower jaw of the sperm whale has teeth. I've heard also that the whale might skim along the sea floor with its' jaws open, shovelling up/snapping up squid and octopus this way.
With regard to how long the beaks remain in the stomach (Clarke 1980: 52, 53):
'If the average whale eats 10 meals a day it would consume 330 squids a day and the average number of beaks in the stomach [1300] would represent 4 days food. This figure, for both sexes combined, is not very different from a direct calculation of the average rate at which beaks are accumulated in whale's stomachs estimated from their food requirements [between 700-800 squids per day for the average female and 300-400 for the average male]. Dividing these figures into the average number of lower beaks recovered from sperm whale stomachs shows the average female retains the beaks for 2.1-2.5 days and the average male for 1.2-1.6 days' [slightly paraphrased].

So it doesn't sound like squid beaks are retained in the stomach for very long at all. Of course that still doesn't explain the incidence of Mesonychoteuthis beaks in the NZ-stranded sperm whale .... the whale would need to have travelled at near-supersonic speed to reach NZ from the Antarctic in such a short period of time. These are, however, 'averages'.

Hope that answers some of your questions. Haliphron (the octopus) is often recorded in the stomachs of sperm whales, but it is a large animal. Moreover, I had one beak referable to this species only, amongst the thousand plus other squid beaks, so it would appear to be a bit of a loner.
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...struggling...not...to crack joke.... about... strong sphincter!!! :lol:

Mixed with the flesh there are often large numbers of cephalopod beaks and there is little doubt that these also have a macerating effect on the freshly ingested food...
How's that for poetic justice?

That is a staggering amount of squid being eaten by sperm whales. Not too surprising considering their size, but still. When I visited Maui in 1992 I picked up a book on humpback whales which had similarly impressive figures on the amount of food they eat.. I can't locate the book, but I don't believe they eat squid. I do recall that their method of catching food is to swim under a school, and then produce billions of tiny bubbles which shoot upward and serve to stun the school. Then the humpback shoots upward to grab its meal. Reading about the behavior of the humpback was one of the things that got me seriously interested in sea life, and led to the creation of this site! For example, I read about how it is unknown (at least in 1992 it was unknown) why the humpback breaches, but it was observed that their eyes are often open during breaching, so it is speculated that they probably do it just to catch a glimpse of the "outside" world. How interesting!

BUT... I digress. :talker: Back to the amount of squid being devoured here -- I'm not sure how many sperm whales it is estimated there are in the world, but with that figure one could easily calculate the number of squid being eaten on a daily basis, by sperm whales alone (which I would have to imagine is their #1 predator). Which then makes me marvel at the amount of reproduction that must be going on amongst squid!

This is great stuff Steve. Only on the Internet can I sit in landlocked Pennsylvania and converse with a marine biologist in scrubs about his first-hand accounts in dealing with things plucked from our oceans. Thanks!
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This is exciting stuff Steve! Although, rather you than me sorting those beaks, I had enough fun :!: with the ones from my squid stomach samples!!

Just a comment, dredging back to my physical oceanography classes, isn't there water of Antarctic origins off the coast of NZ? I'm pretty sure that at least off the east coast of the south island there is Antarctic Intermediate Water (for those who are not familiar with these terms that's kinda like midwater of antarctic origins and it is distinctly different to the other water in this area-----any oceanographers feel free to jump in here, my memory may be a tad hazy!). I guess my point is this; is it not possible that these antarctic species like Mesonychotuethis may occasionally migrate up with this water and be present in NZ waters? Something like a sperm whale is far better equiped to take a "sample" than we are! If this is the case it may in part explain the time thing, the whale hadn't been feeding in the antarctic but in southern NZ???? Some speculation anyway!!

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