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Sci-Fi Science

Some Moray Eels Have Two Sets of Jaws 158

Posted by kdawson
from the one-was-bad-enough dept.
mikesd81 writes that the Mercury News reports that scientists at UC Davis have discovered that some eels have an extra set of jaws deep in their throats that launch forward into their mouths to help pull prey in. "'It looks like a funny pair of forceps with curved sharp teeth,' said evolutionary biologist Rita Mehta, lead author of the research, which appears Thursday in Nature. Before the discovery, scientists thought that all aquatic predators swallowed their prey using suction. By dropping the lower jaw and creating a flow of water into their mouths, they draw in the prey. The two species of moray eels studied by Mehta and Wainwright are the first examples of an alternative feeding method. Instead of sucking, one of these eels bites its prey with its primary set of teeth. It then draws the second set of teeth into its mouth by contracting long muscles. The secondary jaws clamp down on the prey, allowing the eel to move its primary jaws forward in a gulping motion to take in more of the prey. The two sets of jaws take turns until the whole animal has been swallowed." mikesd81 adds a link to a YouTube video of an eel eating, noting "If you look closely right around 34 seconds you can see what looks like the other set of jaws chewing."
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Some Moray Eels Have Two Sets of Jaws

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  • by dc29A (636871) * on Thursday September 06, 2007 @08:34AM (#20493535)
    Well, this certainly seems odd, but, heh, who am I to question the work of the Almighty? Oh, we thank you Lord for this mighty fine intelligent design! Good job!
    • by Jugalator (259273)
      I'm still a bit sad that our Designer don't design animals with three jaws. Imagine what a concept, 50% more powerful than these!
    • by winkydink (650484) * <sv.dude@gmail.com> on Thursday September 06, 2007 @11:06AM (#20495561) Homepage Journal
      and the pain makes you beg
      that's a moray
      • by demonbug (309515)
        Someone was listening to NPR this morning...
        • by winkydink (650484) *
          Someone was listening to NPR this morning...

          I'd sooner bite my own leg. :)

          It's a really, really old pun. I can remember singing it before going snorkeling in Hawaii over 15 years ago.
      • by i.r.id10t (595143)
        Almost a spoof of Spider Robinson's stuff...

        When an eel bites you knee as you swim in the sea, that's a moray

        A New Zealander man with a year 'round tan, thats a Maori

        There's others....
    • Re: (Score:2, Informative)

      by fishfishfish (726241)
      Virtually all fish have two sets of jaws - oral jaws and pharyngeal jaws, also known as the pharyngeal mill. The pharyngeal mill is normally used for crushing and grinding hard foods, such as crustaceans, but morays have evolved the ability to use them to grab prey held in the oral jaws and pull it into the oesaphagus. There's a good interview here: http://www.practicalfishkeeping.co.uk/pfk/pages/it em.php?news=1367 [practicalf...ping.co.uk]
    • Hey if you are into intelligent design check out the awesomely designed tongue replacement parasite [sciencemadecool.com].

      Roll down to "Friday Parasite #10: Tongue Rolling"

      Now only a loving creator could create such a lovable creature such as that.
       
  • by Zwerker (918632) on Thursday September 06, 2007 @08:35AM (#20493555)
    OMG - ALIEN! Defrost Ripley RIGHT NOW!
    • Freaky real life duplicating freaky scifi.

      The second set of jaws grabs and pulls the victim further in; in Alien* their purpose is not clear beyond being scary. Probably the same function, laying the case for interstellar convergent evolution, or common ancestry... It'd be interesting to learn how they came up with the detail in the films

      And btw, why do aliens in movies not have clothes? Flying saucers, ray guns, specialized cow scalpels, but not one pair of shorts or shoes.

      • Re: (Score:2, Funny)

        by Champ (91601)
        Well, the Predator [imdb.com] had a sexy little fishnet get-up.
    • We've got to close the beaches!
    • by Locutus (9039)
      And these guys think it's funny!

      "It looks like a funny pair of forceps with curved sharp teeth," said evolutionary biologist Rita Mehta

      Have they never seen Xenomorph in action, tearing people apart? Great, now it looks like the nightmares might be coming back and it'll be back in therapy and the sleeping pills again. ;-)

      LoB
  • Nature Article (Score:5, Informative)

    by eldavojohn (898314) * <eldavojohn AT gmail DOT com> on Thursday September 06, 2007 @08:36AM (#20493563) Journal

    "If you look closely right around 34 seconds you can see what looks like the other set of jaws chewing."
    I don't believe that is what you are seeing.

    From the original source [nature.com] of information and in the Journal Nature's News [nature.com], these jaws are definitely not for chewing. If you look at the images of x-rays [physorg.com] you will see that these are more 'hooks' or teeth than jaws.

    In the rest of the articles, they talk about this mearly being the method by which the eel pulls the food down or holds on to it. I don't believe any fish (or snakes for that matter) really 'chew' their food.

    I think what you are seeing in that video is the extra skin around the inner part of the mouth billow out as the animal attempts to suck the food in (which as mentioned, most fish do). I don't know a lot about eels so I can't verify that the eel in that video is a moray eel much less one of the kinds that have that kind of device to ingest food. There's over 200 species of moray eels so I guess it would be futile to try and verify it. Still an interesting video but I predict you would see that kind of action when any fish feeds.
    • by TubeSteak (669689)

      I think what you are seeing in that video is the extra skin around the inner part of the mouth billow out as the animal attempts to suck the food in (which as mentioned, most fish do). [...] There's over 200 species of moray eels so I guess it would be futile to try and verify it.
      Come on.. this stuff isn't that hard to verify.
      You don't need high speed cameras.

      Wouldn't a scalpel and some scissors resolve any lingering questions?
      • Re: (Score:3, Informative)

        by Otter (3800)
        Wouldn't a scalpel and some scissors resolve any lingering questions?

        The paper [nature.com], for those with access to Nature, has extensive dissections. It's not just based on the film of feeding, although I think that's what started them looking.

    • by mikesd81 (518581)
      This is why I used the wording "what seems to be.."
    • Morays are saltwater animals. The fish in the video isn't a moray eel, it's a freshwater tropical fish from a petshop, probably Symbranchius marmorotus. Both it and real morays are covered in this months issue of Tropical Fish Hobbyist magazine.

      I've had S. marmorotus before. They're much less agitated at feeding time than this one is. It mush have been really hungry. Uut you know the lemming story, it's just like Hollywoo... uh, youtube to distort things.

      • I was about to make the same comment as you, but I decided to Google first.

        http://www.aquaticcommunity.com/predatory/freshwat ermoray.php [aquaticcommunity.com]

        Anyway, many fish actually have "teeth" near their throat. Anybody who's ever gutted a relatively large carnivorous fish has probably seen this, though the teeth are more like extensions of the gills. Even my 2-inch bettas have some kind of grinders in their throat. I can hear the crunching sounds they make when they chew on pellets.
  • by $RANDOMLUSER (804576) on Thursday September 06, 2007 @08:38AM (#20493593)
    When an eel bites your face, that's a moray.
  • Am I missing something here?
  • My Eel is full of teeth.
  • H.R. Geiger better be notified, the Eel is copying his Xenomorph Alien! Best get Ridley Sct and James Cameron involved too!
  • movie rights (Score:1, Offtopic)

    by psbrogna (611644)
    Anybody else feeling like there's a certain Sci-Fi channel mediocre miniseries in our near future?
    • by Psmylie (169236) *
      Anybody else feeling like there's a certain Sci-Fi channel mediocre miniseries in our near future?

      Sadly, yes. I always feel certain that there's a mediocre Sci-Fi channel miniseries on the way, even before I'd heard of these double-jawed creepy eel things.

      They'll probably pair it up with an erupting volcano and call it "Double-Jawed Lava Eels"

      What the heck... it can't be worse than Ice Spiders, right?

  • Reminds me of one of my favorite quotes:
    Peter: That's what...
    Brian: If you say "that's what she said" one more time, I am gonna pop you.
  • Two jaws? Pah. (Score:3, Interesting)

    by pzs (857406) on Thursday September 06, 2007 @08:50AM (#20493735)

    That's nothing. [bbc.co.uk]

    Peter

  • The second set of jaws is quite interesting. One of the claims of the Creationists (yeah, it predates ID movement and it has been debunked so thoroughly even IDers don't mention it anymore) is the difference in articulation of the jaw between reptiles and mammals. The way the Creationists said it, the jaw first has to be disarticulated from the joint and then re-articulated around a different bone end and during the interim the animal would not be able to eat. So such an evolution is impossible.

    Then speci

  • From TFA:

    "It's like a scene from an Aliens movie: a scaly underwater creature looking something like a piranha crossed with a python strikes at its prey which is then reeled deeper into the beast's throat by a second set of toothy jaws."

    Too bad moray eels don't actually have scales...

  • Other than a tenuous link with the Alien film which might be somewhat geeky I can't understand why this is newsworthy. Are these eels part of the open source community? I don't think so.

    • Re: (Score:3, Funny)

      by Overzeetop (214511)
      Some of us are still sore over Ubuntu not having an "ecstatic eel" release. See, it all ties together.

      Oh, and for the record, the Alien tie-in is reason enough on /. because, well, it's /.
    • Prejudice abounds! Moray Eels are living beings too! Maybe they want to learn how to use a computer and we just haven't made one that's accessible. We should enact a new law requiring all electronics to have an eel interface to allow them to use them!
    • by plague3106 (71849)
      Um, because most geeks here also have an interest in science outside the computer variety. These kind of stories aren't new here... they've been on /. for quite a while now.
    • Open your hand, and gently wave it back and forth in front of your face... now re-read the summary:

      ...deep...throats...

      "Instead of sucking, one of these ... bites ... with its primary set of teeth. ...then ... The ... jaws clamp down ... in a gulping motion to take in more ... until the whole ... has been swallowed."

      If that doesn't conjure up images of open sores, I don't know what will!

    • by gstoddart (321705)

      Other than a tenuous link with the Alien film which might be somewhat geeky I can't understand why this is newsworthy.

      Dude, it's in the science section. For some of us, daily news about science is a good thing. It's something I didn't know when I woke up this morning.

      Cheers
  • by brunes69 (86786) <slashdot@keirste ... minus physicist> on Thursday September 06, 2007 @09:05AM (#20493909) Homepage
    Further on this, according to NASA, 50 double-jawed Moray Eels can chew 100 objects simultaniously. Even further, 100 double-jawed Moray Eels can chew 200 objects.
    • Re: (Score:1, Funny)

      by Anonymous Coward
      Further on this, according to NASA, 50 double-jawed Moray Eels can chew 100 objects simultaniously. Even further, 100 double-jawed Moray Eels can chew 200 objects.


      Yes, but the license EULA limits you to only 10 objects at once

  • Would not eel anatomists have made this discovery years ago?
  • I think the majority of Moray Eels are nocturnal creatures so "They Mostly Come Out at Night...Mostly"
  • by PIPBoy3000 (619296) on Thursday September 06, 2007 @09:33AM (#20494281)
    My favorite Alien-like feeder is the Dragonfly larvae [snh.org.uk]:

    Dragonfly larvae have a remarkable tool at their disposal when hunting prey: their lower lip is modified into a long, hinged jaw terminating in two sharp, hook-like mandibles. This is known as the "mask". When a prey is in sight, the mask is thrust forward and the prey instantly impaled on the hooks, then drawn back to the mouth and eaten.
    There's also a good video [youtube.com] of the jaw in action.
  • When the tide rises high
    And a snake bites your thigh,
    That's a moray!
  • I'd think the structure described (no pics?) would be pretty apparent?
    Or did they just think they were vestigal?
  • Run away!!!
  • pharyngeal jaw (Score:4, Insightful)

    by jbeaupre (752124) on Thursday September 06, 2007 @10:12AM (#20494787)
    A second jaw is not new. In fact, it is a defining characteristic of some fish (cichlids) http://en.wikipedia.org/wiki/Cichlid#Anatomy_and_a ppearance [wikipedia.org].

    Cichlids are a great example of evolution, with some species only a couple thousand years old. The second jaw is thought to be why they are so successful and diverse.
  • News? (Score:4, Interesting)

    by u8i9o0 (1057154) on Thursday September 06, 2007 @10:25AM (#20494985)
    Over two decades ago, I noticed a second set of jaws in a moray eel on display at a local pet store.
    If I had known that such an observation was newsworthy, I'd have shown it to more than just my brother and father.

    Since I see this as a non-story, I'll offer an anecdote:

    Seeing the second set made me even more afraid of morays - they're creepy enough with just one set. The worst was seeing one with a body cross section similar in size to a 3 liter soda bottle just a few yards from me while SCUBA diving. Daggers for teeth. That thing could have easily killed anyone in the group. Not something you want to meet that far under water, protected only by a bathing suit and basic SCUBA gear.

    BTW, even though the article makes SciFi comparisons, this article should not be categorized under SciFi. Otherwise, every subject should be categorized under SciFi (find me a subject that cannot be compared to SciFi).
    • Re:News? (Score:4, Informative)

      by DerekLyons (302214) <fairwater@gmFREEBSDail.com minus bsd> on Thursday September 06, 2007 @01:15PM (#20497285) Homepage

      Over two decades ago, I noticed a second set of jaws in a moray eel on display at a local pet store.
       
      If I had known that such an observation was newsworthy, I'd have shown it to more than just my brother and father.

      Both the summary and part of the article are written to erroneously imply that the jaws were just discovered... But what was actually discovered (and is newsworthy) is the function of those jaws.
    • by rho (6063)

      I was just gonna say...

      I seem to remember reading this information, and the function, years ago. I mean, a lot of years ago, like in a kids' science book, so going back 25 years or thereabouts. I could be completely wrong, and probably am, but my first reaction when I read the Slashdot article was "I knew that already!"

  • After reading the description, the first thing I thought of was the goatse photo... Something is very wrong with me
  • Some eels have been reported to fight off predators with their thick green acid blood.
  • ...of the movie Aliens where that internal mouth comes out of the main mouth? What's a redundant?
  • Dean Martin might have sung it like this:

    "What is that thing with the great ugly teeth ... that's a Moray."
  • Most fish have pharyngeal jaws, although they are normally used for crushing rather than 'biting', having bony plates or small teeth. The moray eels have pharyngeal jaws that are used for grabbing prey and drag it into the mouth - most fish will suck their prey into the mouth, but since moray eels live in small crevices in reefs, they don't have enough room for this, so they've evolved this instead.

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