Whales are diverse marine mammals with distinct feeding adaptations. Not all species possess teeth; their oral anatomy dictates their feeding method. This divides whales into two main categories: those with teeth and those with specialized filter-feeding structures.
Whales with Teeth
Some whales, known as toothed whales or Odontoceti, possess teeth. These teeth are typically conical and uniform in shape throughout the mouth. Unlike human teeth, whale teeth are not designed for chewing food into smaller pieces. Instead, they are primarily used for grasping and holding prey firmly.
Toothed whales are active predators that hunt a variety of marine animals, including fish, squid, and even other marine mammals. For instance, bottlenose dolphins often use their teeth to capture fish and squid. Orcas, also known as killer whales, employ their strong teeth to seize larger prey such as seals, sea lions, and other whales.
Sperm whales, which are the largest toothed predators, have prominent teeth in their lower jaw that they use to catch deep-sea squid. These teeth secure slippery prey before swallowing it whole. The number and arrangement of teeth can vary among different species of toothed whales, reflecting their specific dietary preferences and hunting behaviors. Some species, like narwhals, have evolved a single, elongated tusk, which is actually a modified tooth, used for sensing their environment or possibly for social display.
Whales with Baleen
Another major group of whales, known as baleen whales or Mysticeti, do not have teeth. Instead, they possess baleen plates, a unique and flexible structure made of keratin, the same protein found in human fingernails and hair. These baleen plates hang down from their upper jaw in rows, forming a giant sieve inside their mouths.
Baleen whales are filter feeders, meaning they strain small organisms from large volumes of water. They consume vast quantities of tiny prey, such as krill, copepods, and small fish. Blue whales, the largest animals on Earth, are examples of baleen whales that feed almost exclusively on krill by taking in massive gulps of water and then expelling it through their baleen plates, trapping the food inside.
Humpback whales use a technique called “bubble-net feeding,” where they work cooperatively to blow bubbles in a circle, creating a “net” to corral their prey before surfacing through the middle with open mouths to engulf the concentrated food and water. Gray whales are bottom feeders, often scooping up sediment from the ocean floor and filtering out small invertebrates. The baleen acts as an efficient filter, allowing water to escape while retaining the small food particles.