My vote goes to the Orca.
Although sharks are not stupid (they can be trained, and have a fairly good memory), I do not believe that they are smart enough to block a dolphin's path to the surface. Orcas, however, have been known to do so to their larger cetacean prey such as gray whales. Orcas have been known to eat Great Whites; that video is simply the only video recorded incident.
As far as size goes, a male Orca can reach about 9.5 m (31 feet), with the largest recorded animal being about 9.7 m (32 feet). Females can reach 8.5 m (28 feet). Great Whites, on the other hand, can reach around 6 m (20 feet).
Originally posted by Dawson
I do not believe that they are smart enough to block a dolphin's path to the surface.
The Orca is the largest member of the oceanic dolphin family, Delphinidae. The name "Killer Whale" is thought to have evolved from a mistranslation of the Spanish name meaning "Whale Killer".
Originally posted by Jabba the Hutt
I watched a vido today in bio about a crazy-ass killer whale. Could a KW take a GWS?
Originally posted by Alpha Centauri
True, Orcas are extremely smart and in reality it would be them. That's how they hunt shoels of fish. Forcing them by almost herding them with accurate tactics and ambush techniques.Yet if you unleashed them both at each other with full fury, I wouldn't ever count out a Great White.
-AC
Nor would I. With its life on the line, I'm certain that a Great White would put up one hell of a fight, and I would not count one out either. If bets were being placed, however, I would place mine on the Orca.
The great white has a chance if it attacked the orca first. It is faster and has a more powerful bite, and if it sees to strike near the base of the orca's skull it could make the kill.
But by purely comparing both of the animal's statistics, the killer whale is clearly the most powerful, dangerous and durable of them.
The orca is used to dealing with larger prey, unlike the great white. This combined with it's greater intelligence will make the orca attack more efficiently in this duel.
The orca has a thick layer of fat beneath it's skin, making it hard for even a great white to inflict serious damage to vital organs in a single bite. While the shark's organs are rather accessible for the orca's jaws, one bite to the side offs the shark.
On top of that, the orca is powerful enough to literally break the shark in two if it shook it around after biting in to it.
Then something about teeth; the shark bites, twists and saws of a chunk of flesh and by that releases the rest of the animal. This grants the orca a chance to retaliate, while the bite of a orca is something the shark can't release itself from. With a hold on the shark, the orca can do with it what it wants.
And don't bother about the orca's need for oxygen, it can do without a breath (while hunting) for a long time, way long enough to own some shark.
Unless the shark intendedly aims to kill the killer whale by surprise, the killer whale will win the fight.
In the water when dealing with two big powerful animals like this it normally comes down to who attacks first.
On the discovery channel I watched a group of researchers come upon a GWS eating the carcass of a KW. The problem is they did not know if it had killed it or if the KW had died from some other reason.
A fully grown GWS can actually get to 25 feet and higher but those sharks have been practically hunted down to nothing. They are given the name of Submarine because they were so big.
GWS are generally more dangerous because they can stay under water they do not need to surface, have a more powerful bite, and are faster. These mean that one can not count out the GWS to soon.