Here's why:
* Size and Power: Killer whales are large, powerful apex predators. Even the largest sharks, like Great Whites, are unlikely to attempt to prey on a healthy adult orca.
* Orca Behavior: Orcas are highly intelligent and social animals. They often hunt in groups, making them formidable opponents even for sharks.
* Diet: While sharks are known to eat a wide variety of prey, their diets typically don't include large marine mammals like orcas.
However, it's important to remember that the ocean is a complex ecosystem with ongoing interactions. While there may be no evidence of sharks eating healthy adult orcas, there could be rare instances of scavenging or attacks on injured or young orcas.