The Dorsal Fin – Shark News

Nat Geo video: Did killer whale attack great white shark using tonic immobility?

by on Sep.08, 2010 at 12:40 pm, under Shark News Stories, Shark Videos

The video above from NatGeoTV.com presents a theory that a killer whale from the L.A. Pod of orcas might have used tonic immobility during a 1997 attack on a great white shark at the Farallones. The theory suggests that the orca (identified as “CA2″) potentially rammed the unsuspecting white shark, stunning it. While the shark was still disoriented the orca could have either grabbed the great white while it was on its back or flipped it over. The orca could have then held the shark upside down in its jaws, keeping it in a state of tonic immobility until the shark drowned.

While there is no hard evidence or clear-cut video footage of orcas inducing tonic on sharks in the NatGeo feature, the video does include video evidence of killer whales attacking stingrays in New Zealand using a similar technique. As seen in the footage, the killer whales approach the rays upside and grab them with their mouths, then right themselves, so that the rays are upside-down and effectively immobilized. Researchers hypothesize that if orcas have learned to use this technique on rays, then it’s not far-fetched to assume they could use a similar technique on sharks.

On a side note, some of the underwater footage of the “great white shark” in this clip features a shark that is clearly not a white shark. While I admittedly am not great at identifying certain species of sharks, I’m guessing the footage features either a lemon shark or a bull shark. Anybody care to enlighten me on the species seen at around 3 minutes in?

Thanks to DeepSeaNews.com for the video find.

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10 Comments for this entry

  • Matt

    The ‘great white’ seen in the video that you were referring to is in fact a lemon shark, 100% sure.

  • Dr. Michael Domeier

    The tonic immobility theory is interesting, but I don’t think the orca held the shark upside down long enough for it to suffocate. It would take quite some time since white sharks are very capable of making prolonged dives to very oxygen poor waters. However, the tonic immobility could have been used to control the shark until a fatal crushing bite could be made to the gill arches.

  • steven morgan

    What i dont understand was that all the people on the boat with camera’s looking at the orcas why didn’t anybody film the white shark swimming beside the boat before the attack the lady on the boat said she saw the shark but she took no footage of the shark even though she had a camera im not convinced

  • Jill Brooks

    The underwater footage at 3 minutes in is a Lemon shark, if you watch the full TV programme -The whale that ate Jaws, they do a section on tonic immobility which they filmed with Dr Gruber here in Bimini with a sub adult Lemon shark, just to demonstrate how they go into tonic.

  • Robert Mcghee

    Definately not a White Shark at time you mentioned. And far too clear to have been shark from that attack.Footage of another shark has certainly been added to the original footage taken that day. Nicely done by CA 2, and wrong time and place for White Shark known as Jerry Garcia.

  • Harris Iasonas Haralabides

    I am not convinced that the killer whales actually prey regularly on these animals. The CA2 individual had just been fed (sea lion) and even though I’m no expert in the amount of food Orcas need to sate their hunger I believe that this was an attack aimed primarily to eliminate competition. It is a well documented behaviour amongst predatory species that compete for the same resources in the same ecosystem. Furthermore, even though it’s a far fetched theory, I wouldn’t rule out the possibility that the kill was made to act as a warning beacon for other Great Whites thus preventing them from competing with the Orcas. It was stated in the documentary that prey was scarce at that particular season and that the end result of that kill was that the scent of the rotting carcass of that great white acted as a deterrent for other great whites. As a matter of fact no sharks were observed in that area for the whole season … Finally, how about another possibility: the killer whale was “showing off” to humans that were present at the scene. How can we be certain that when watching a scene from above water we don’t actually influence behaviours like these? IMHO, we shouldn’t exclude any of these possibilities when dealing with such intelligent and complicated mammals.

  • Sarah

    Does anyone know what type of Orca CA 2 is? I’ve heard that there are about five species of orcas, including “transient” orcas, which are the most aggressive. Can someone enlighten me? My knowledge is based more around sharks than whales.

  • JoeDiver1119

    CA 2 belongs to the L.A. Pod which at presnet seems to not fit into any of the 3 catagories of killer whales (resident, transient and offshore). They appear to have their own entirely unique ‘culture’ among which is the knowledge of Great White Shark vulnerabilities and the know-how to take them down with relative ease.

  • JoeDiver1119

    I tend to agree with Dr. Domeier (not a difficult task if you know his credentials), I believe the tonic immobility is just a means of subduing the shark before a fatal wound is able to be inflicted. The whale knows of the potential dangers involved in hunting such large and fierce prey and I dont believe it would take the chance in keeping it alive any longer than was necessary if for no other reason then to protect itself. If it has figured out turning a shark upside down renders it helpless then surely it knows a crushing bite to the gill arch is 100% fatal. Game over.

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