In looking at the walrus wiki it says.
Raw oysters are usually pretty tightly sealed and it requires a knife and deft hand to crack open the shell to get at the meat. I’m not clear on how a walrus is manipulating a clam into position with his mouth, forcing the shell open, then producing enough suction just with tongue action to pull the clam out.
Is there some movie or diagram showing how this works?
The trick is that you want to know what’s going on inside the walrus’ mouth as it’s feeding.
It’s really hard to get external images of walruses feeding in the wild - you can watch videos from a 2003 paper here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC270045/ (scroll down to supplementary material for 3 videos.) - you can see how little information one might get from such videos if these are some good ones.
It’s easier to get external videos in captivity, but it still won’t show what happens inside the walrus’ mouth, and I don’t know of an animation that might show it.
But I think you’re discounting the amount of crushing walruses do as they feed - it’s not like they will daintily suck only the flesh out without touching the shell, they most likely are crushing the shells to some extent, and feeding on molluscs smaller than what you might be thinking; a common size for a prey mollusc might be 1-4 ounces. Remember that walruses are large mammals, and can probably apply many hundreds or thousands of pounds of force with their jaws.
I did a Google Video search for “walrus feeding mollusc” and didn’t find anything useful. I doubt “mollusk” will return better results, but it might be worth a try.
Thanks for the link. I’m surprised in the paper that the precise mechanics of how locates food is still open to competing theories, you’d have thought that some enterprising marine biologist PHD would have laid it all out by now.
There’s potential here for a superlative comment on someone’s Oral Communication skills. Only I’ll bet most women wouldn’t want to be compared to a Walrus.
Less than an hour to get a good answer complete with references & videos to a question about the inside of feeding walrus’s mouths.
Gotta love the Dope.
Bravo wevets.
Appreciate the responses but I’m still not clear on the process. If (per the documentation) walruses are eating 3000 to 6000 clams at a time over a few hours of feeding there’s no way each clam is being individually positioned by the mouthparts for suction extraction. There’s just no time.
Ho Lee Shit! Tell me walrusses aren’t really that huge!
I am pretty sure that is a sea lion with the bucket. Walruses are bigger.
No external ears means it’s not a sea lion. No tusks means it’s not a walrus. I know that elephant seals can get that large.
According to knowyourmeme.com on the lolrus:
"Typically a walrus who has lost a bucket, is searching for a bucket, or is enjoying a recently found bucket of some kind.
PROTIP: lolrus is not actually a walrus — he was an incredibly obese seal named Minazo who passed away in 2008 at the ripe old age of 11 (pic)
May he find his bukkit in heaven."
I understand. In general, this isn’t a subject about which very much is known. To give you an idea of how sketchy knowledge in general on what goes on inside a walrus’ mouth is, perhaps the best available information on this comes from a 1991 paper with results based on a mere 2 (yes, two) walrus skulls:
http://www.aquaticmammalsjournal.org/share/AquaticMammalsIssueArchives/1991/Aquatic_Mammals_17_3/Kastelein.pdf
From Kastelein et al. 1991. The anatomy of the Walrus head. Aquatic Mammals v. 17.3, pages 178-179.
I’m not really enough of an anatomist to judge how accurately this paper may reflect reality, but briefly summarized, the Walrus traps clams with the siphon inwards at its lips using both whiskers and lip muscles. Using the tongue like a suction pump, it can suck out the meat. It seems to do so in about 10 seconds, which is not inconsistent (although it is quite an achievement! and probably represents an unusual amount of feeding time) with feeding on 6000 clams in a day, since such an effort would take about 17 hours.
There are photos and diagrams in the linked paper - but the scanned photos are none too useful, you might be able to Interlibrary loan the paper to get a better look, but I hope they help.
ETA: I should probably also mention this is likely not as clean a process as when humans eat clams. Walruses are likely to accept a certain amount of shell with the meat, probably more so than humans would.
Thanks, LSLGuy!
