It’s difficult to imagine that a giant octopus could have gone undescribed until 2017, but this is actually what happened with the newly described frilled giant Pacific octopus (no scientific name yet, but most likely belongs to the genus Enteroctopus). This giant octopus is pretty commonly found in Alaska, so why has it gone unnoticed for such a long time? To answer this we need to go back to a discovery in 2012.
First clues of the undescribed frilled giant Pacific octopus
Back in 2012, researchers from Alaska Pacific University and the US Geological Survey took small tissue samples from giant Pacific octopus (Enteroctopus dofleini) in the Prince William Sound in Alaska and found some of the samples to be genetically different from the sequenced genome of the giant Pacific octopus. This meant that there had to be a new species, or even a subspecies out there living alongside the giant Pacific octopus that no one had really known was different from it. Unfortunately this study had only collected very small tissue sample, so they could not compare the samples to a complete octopus, and were therefore unable to tell if there was a morphological difference between them.
This was of course a big mystery, and everyone wanted to know if there was in fact several different species that looked the same, or if it would be possible to tell them apart without doing a complete genetic test.
A giant Pacific octopus. Image by Magnus Manske, posted with the Creative Commons Attribution 2.0 Generic license.
The same researchers tries to find the difference
Fast forward a few years, and the same researchers from Alaska Pacific University sets out to find out if there is indeed a morphological difference. They allied themselves with fishermen that often caught octopuses as bycatch, and were able to get their hands on 21 octopuses.
The results showed that one third of the caught octopuses were morphologically different from the regular giant Pacific octopus. As per the scientists own words about the newly found octopus species:
(They have) an absence of longitudinal mantle folds, the presence of a lateral mantle frill comprised of a semi-continuous line of broad merged papillae forming a frill or flap along the mid-lateral mantle, the absence of papillae or rugose texture on the ventral mantle below the frill, and two distinctly seperated frontal white spots (rather than a single simple or compound spot, or none).
To put this into english, the frilled giant Pacific octopus has frills that kind of looks like eyelashes around its eyes, and a frilly ridge running down its mantle. These small differences might not sound like a big deal, but this is certainly enough to make them their own species. Genetic tests of the same animals also concluded that they were their own species. With some training, it should also be entirely possible to tell the two species from each other when finding them in the wild, or as bycatch.
The new octopus has not gotten its scientific name just yet, and there needs to be more studies of it before this point, but the scientists who found this has decided to use the common name frilled giant Pacific octopus in order to make it easier to know the difference.
Why it matters that we now know that there are two giant octopus species in Alaska
I guess some of you might ask yourself “why does this even matter”? At first glance it might not seem that important to know that we now have two different species of giant octopus in Alaska instead of one, and considering the fact that a third of the caught octopuses were of the new species, it is most likely not endangered.
However, now that we do know of its existence, we are able to study it and determine if this new species is in need of protection. A lot of octopuses end up getting killed as bycatch from fishermen, and it is therefore very important to keep a track on their population number. Many scientists fear that octopuses will be a victim to the climate change, since they are somewhat fragile compared to a lot of other marine species. Now we should be able to determine the potential need for protection, and act accordingly.
Thanks for reading
I linked to my sources in the text, so make sure to take a look at them if you want to learn more about this new species. In addition, I urge you to take a look at the project website that goes into a lot of detail without being too difficult to understand.
If you want to learn more about octopuses in general, make sure to check out my post about observational learning in the common octopus. It’s almost 7 months since I posted that, so many of you have probably not seen it. Thanks for reading!