Tracking Giant Pacific Octopuses in Alaska

Fish & Invertebrate sightings and descriptions, hosted by resident NWDC ID expert Janna Nichols (nwscubamom).
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John Rawlings
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Tracking Giant Pacific Octopuses in Alaska

Post by John Rawlings »

Another cool photo article from the BBC:

http://www.bbc.co.uk/nature/17561456

I particularly liked the fact that the previously believed "range" of a hunting GPO has been expanded. Previously thought to be 250 sq meters, they found that large GPOs hunted over an area around 50,000 sq meters! That's quite a huge change!

- John
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morayeel
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Re: Tracking Giant Pacific Octopuses in Alaska

Post by morayeel »

This article is so cool!! Thank you for posting it. In addition to the expansion of hunting range, I also like the fact they stay hiding 94% of the day. That means if you see an octopus open, you are very lucky. :)
Tidepool Geek
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Re: Tracking Giant Pacific Octopuses in Alaska

Post by Tidepool Geek »

Greetings,

The study shown in this article is essentially a confirmation of one done about 20 years ago at Saanich Inlet by Jennifer Mather and NWDC forum member Jim Cosgrove. You can read about this and other studies in Jim's book "Super Suckers" and the original papers may be obtainable by doing a Google Scholar search on "JA Mather".

The Mather and Scheel studies seem to have generated very similar results - Saanich GPO's appear to have a slightly larger hunting range than do PWS residents which may have to do with the size of the animals (repotedly, Puget Sound GPO's get bigger than Alaskan GPO's)

Confirmationally yours,
Alex
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johndo88
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Re: Tracking Giant Pacific Octopuses in Alaska

Post by johndo88 »

Am I doing the math right. 50,000 sq m is about 31 square miles?
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Greg Jensen
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Re: Tracking Giant Pacific Octopuses in Alaska

Post by Greg Jensen »

No, it's about 0.02 square miles- if it were square, it would be 733.6 ft on a side.
Also note the original estimate was 250 square meters, not 25 as stated in the first post.
KneeDeep
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Re: Tracking Giant Pacific Octopuses in Alaska

Post by KneeDeep »

looks like I might be doing some dives between of 01:00 and 04:00... you know, for science.
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John Rawlings
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Re: Tracking Giant Pacific Octopuses in Alaska

Post by John Rawlings »

Greg Jensen wrote:No, it's about 0.02 square miles- if it were square, it would be 733.6 ft on a side.
Also note the original estimate was 250 square meters, not 25 as stated in the first post.
Thanks, Greg!

You're absolutely correct. I obviously missed a digit when I was typing, and I've corrected the original post so that there will be no confusion if/when anyone else reads it.

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edofleini
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Re: Tracking Giant Pacific Octopuses in Alaska

Post by edofleini »

Hello John: In a recent study by David Sheel in Alaska he has some evidence that suggests that there may be a second species that is very similar to the GPO but is unidentified as yet. That may put a wrinkle in our understanding of this animal if it turns out to be a complex like O. vulgaris. Science is such fun!

Jim Cosgrove
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