Whale # 10 stomach content analysis

Discussion in 'ID Requests' started by Steve O'Shea, Dec 26, 2004.

  1. Steve O'Shea

    Steve O'Shea Colossal Squid Supporter

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    Whale # 10 was the first whale stomach we ever received, back in good-old 2002. This male stranded early (7am) 28 November 2002 on the southern side of Mahia Peninsula, NZ. The stomach contents were retreived for us by Debbie Freeman of New Zealand's Department of Conservation.

    [​IMG]

    Like 'Whale's 1-6 and 8 and 9', as far as I know (to the best of my efforts), every squid beak in the stomach was retained (I've yet to count the upper beaks). The identifications must be treated as provisional, and a number of the beaks have proven quite a challenge to identify. As for other beaks identifications in other whales, 'Octopoteuthis/Lepidoteuthis'), cranchiids, and this time Histioteuthids prove quite diverse, and sometimes problematic.

    There's a lot of work to do yet on this stomach - a lot of checking of identifications. Nevertheless, I don't expect too many changes. I'm putting it online now because it's real interesting, and sparked the thread 'squid beaks from whale stomachs' so long ago.

    If you like you can look at the squid composition of this whale, compare it to that of the previous lot, and try and make some sense out of the jigsaw (again based on what we know of the New Zealand and adjacent water mass squid faunas). I've not provided lower rostral lengths for the beaks, as I've yet to measure them.

    Identifications are based on lower beaks.

    Here goes:
    Whale # 10, male, ~ 13m, stranded 28 November 2002, Mahia Peninsula (East Coast North Island, NZ).
    Number of upper beaks: TBD
    Number of lower beaks: 409
    Number of extensively damaged/unidentified beaks: TBD (~ 20)

    Lower beak-determined squid composition in diet of Sperm Whale # 10
    Architeuthis dux: 5
    Pholidoteuthis boschmai: 8
    'Octopoteuthis' sp.: 9
    'Lepidoteuthis grimaldii': 5
    Taningia danae: 10
    Moroteuthis 'ingens': 35
    Moroteuthis 'knipovitchi': 9
    Moroteuthis robsoni: 17
    ?Kondakovia longimana: 1 (extensively damaged, large)
    Histioteuthis cf. eltaninae: 162
    Histioteuthis miranda: 28
    Histioteuthis sp. A5 (sensu Clarke): 17
    Histioteuthis spp.: 8
    Mesonychoteuthis hamiltoni: 28
    Cranchiid Type 1: 7
    Cranchiid Type 2: 7
    Cranchiid Type 3: 3
    Cranchiid Type 4: 9
    Cranchiid Type 5: 11
    Chiroteuthis sp.: 3
    Gonatus sp.: 18
    Mastigoteuthis sp.1: 1
    Mastigoteuthis sp. 2: 4
    Haliphron atlanticus: 4

    A lot more could be said about this one. See the 'squid beak variation (and stuff)' thread; the smallest Architeuthis beak thus far, and series of Mesonychoteuthis beaks recovered from this whale are depicted in this thread.
     
  2. ArchyNorth

    ArchyNorth GPO Supporter

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    Hey there,

    After reading all the stomach content threads and doing some basic number crunching, a question has popped up in my head.
    I'll get to the actual question in a second, but I want to show you what led me to wonder.

    After reading the species names found in the stomach contents of the 10 whales, I noticed that the species Histioteuthis cf. eltaninae makes up a relatively large percentage of the species found.
    eg,

    #2 - 13 species, with Histioteuthis cf. eltaninae making up 23%
    #3 - 14 species, with Histioteuthis cf. eltaninae making up 18%
    #4 - 9 species, with Histioteuthis cf. eltaninae making up 21%
    #5 - 15 species, with Histioteuthis cf. eltaninae making up 15%
    #6 - 12 species, with Histioteuthis cf. eltaninae making up 17%
    #7 - 20 species, with Histioteuthis cf. eltaninae making up 29%
    #8 - 9 species, with Histioteuthis cf. eltaninae making up 85%
    #9 - 17 species, with Histioteuthis cf. eltaninae making up 59%
    #10 - 24 species, with Histioteuthis cf. eltaninae making up 40%

    Whales #4,5,6 have Histioteuthis miranda as their highest percentage at 33%,29% and 55% respectively.

    Whale #3 seemed to have a less discrimiting taste with 4 species between 13% - 18%.

    So, my question is: Is Histioteuthis cf. eltaninae incredible common in the waters where the wales came from? Or are they easier to catch?
    I'm just wondering why the seem to comprise such a large percentage of these whales diets.

    I know that 10 whales is a small sample size, and all the numbers may not have been listed. Also all the %'s I gave are approximations.


    A quick second question if I may. I assume that classifying the beaks is based mostly off of metric analysis. Is there a large variation in shapes and sizes between species?

    Very interesting stuff.
     
  3. um...

    um... Architeuthis Supporter

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    Is there a nice spreadsheet of all these data somewhere?
     
  4. ArchyNorth

    ArchyNorth GPO Supporter

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    Hey Umm,

    If you are asking about my attempt at complex math, it was all pencil and paper with a 15 year old calculator. :smile:

    Though, I think a compilation of known stomach contents, put into spreadsheet form, would be interesting to see.

    Steve has done a wonderful job with the stomach content threads, I could use the information he has provided and make one if someone wants. Shouldn't take me too long.

    Would be fun.
     
  5. um...

    um... Architeuthis Supporter

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    I started one while waiting for supper to cook. I'm ~50% through the mindless part of it as the oven timer starts beeping. I'm going to give it hyperlinks to the Tree of Life pages, I think.

    Is that burning I smell?

    ...
     

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