Here's the breakdown:
* Baleen whales are the type you're likely thinking of. They have baleen plates instead of teeth, which they use to filter out tiny organisms like krill, plankton, and small fish from the water.
* Toothed whales have teeth, and their diet varies greatly depending on the species. Some eat squid, fish, and even other marine mammals, while others specialize in eating specific types of prey.
So, while baleen whales are known for their plankton-rich diet, not all whales are limited to eating plankton. The diversity of whale species means a wide range of feeding strategies and diets.