Predatory interactions between sharks and large squid

Large squids are evidently an incredibly important part of deep sea ecologies; giant whales have revolved their lives around feeding on these sizeable cephalopods, but it appears they are not alone. Research published in October of 2023 suggests predatory interactions between large-scale deep sea squid, potentially even the Giant Squid (Architeuthis dux), and great white sharks around Guadalupe Island, Mexico - https://www.nature.com/articles/s41598-020-74294-4

figure 1

These sharks bear sizeable, nasty scars that suggest an impressive struggle, which were first documented in 2008. Surveys each year showed that these interactions were occurring consistently in deeper waters. 14 different individual sharks were recorded with these scars; adults and juveniles of both sexes bore these scares, but subadult males were the most common. These scars were very clearly left by squid suckers due to their shape, and their position suggests that they were defensive. Large squids are an incredibly nutritional meal, containing many proteins, fatty acids, and carbohydrates, perfect for a juvenile on the cusp of sexual maturity; these would be vital for the development of reproductive processes. 

There was actually a Shark Week documentary called Jaws vs Kraken on this paper and its potential implications, albeit a fair bit dramatized, revolving on what an interacting between a Giant Squid and great white shark could entail 

Interestingly, these are not the only documented instances of sharks interacting with large squids – a 2020 paper paper reported similar scars on a male Oceanic Whitetip around Hawaii, likely feeding on squids for the same reason.

There's also this 2012 footage of a blue shark attacking a (already dead) giant squid

And a 2004 paper which went over the squid remains found in the stomachs of dissected sleeper sharks. This study dissected 36 sleeper sharks and reported a large portion of cephalopod prey (52% by mass), calling the shark "a fish with a sperm-whale-like diet", but also note that they don't know if they prey on live Architeuthis or scavenge dead ones

A TONMO thread further details potential sleeper shark specimens with suckermarks on them, there's a couple great links and images in there, would highly recommend reading through - https://tonmo.com/threads/possible-mesonychoteuthis-sucker-marks-on-an-antarctic-sleeper-shark.18691/

On the other side of the coin, there are reports of squids eating sharks; apparently an arrow squid was filmed doing this in 1998 



Architeuthis was also implicated in this incident from 2022, although this remains unconfirmed - https://www.newsweek.com/fishermen-big-shark-eaten-larger-shark-giant-squid-mystery-1695862

Squids and sharks interacting has been portrayed in the media as well, such as in The Meg (2018) - https://www.youtube.com/watch?v=A93aV9U46A4

and The Future Is Wild - https://www.youtube.com/watch?v=kedHEfbeAzU&t=1140s

On a fun little speculative sidenote – we have potential evidence of eusociality in great white sharks. The, albeit incredibly unlikely, potential for a pair or “pack” of great white sharks hunting giant squid is a fun one.

There's plenty of potential for further observations of these sorts of interactions, I cannot wait to see what we find next!

Sources - https://drive.google.com/drive/u/3/folders/1wmFW2x2b9iukbBO87HvKMVALJGEVvNlQ