Whales are diverse marine mammals, and their dental structures are a common topic. Not all whales possess teeth; some have evolved a different, equally effective feeding apparatus. This fundamental distinction divides them into two groups, each with specialized feeding adaptations.
The Two Major Whale Suborders
Whales belong to the order Cetacea, divided into two primary suborders. The suborder Odontoceti encompasses toothed whales, which have teeth. Mysticeti includes baleen whales, which lack teeth and use baleen plates for feeding. These two groups represent different evolutionary paths, leading to varied methods of prey capture.
Toothed Whales: Masters of Prey Capture
Toothed whales, or odontocetes, are predatory marine mammals that use their teeth to seize and consume prey. These whales have a single blowhole. Their teeth vary in number, size, and shape; some species can have over 100 teeth, while others, like certain beaked whales, may have only a few or even teeth that do not fully erupt. Their teeth are primarily for grasping, not chewing, as they swallow food whole.
Many toothed whales, including dolphins, porpoises, sperm whales, and orcas, use echolocation to navigate and locate prey. They emit high-frequency sounds that bounce off objects in the water, providing a clear acoustic image of their surroundings, even in dark or murky environments. Their diet includes fish, squid, and other marine mammals, which they hunt using their specialized teeth and sonar. For example, sperm whales dive to great depths in search of giant squid, while orcas are apex predators that hunt a wide range of marine animals.
Baleen Whales: Filter-Feeding Giants
Baleen whales do not have teeth. Instead, they have hundreds of baleen plates, comb-like structures made of keratin, like human fingernails. These plates hang from their upper jaw and are arranged like sieves, allowing them to filter small organisms from water.
Baleen whales employ various filter-feeding strategies to capture prey like krill, copepods, and small fish. Gulp feeders, like blue whales and humpback whales, engulf large amounts of water and prey, then use their tongue to force water out through the baleen, trapping food. Skim feeders, such as right whales and bowhead whales, swim with their mouths open through patches of plankton-rich water, filtering food as they move. Gray whales are unique bottom feeders, plowing through seafloor sediments to filter out invertebrates. Despite their immense size, these whales rely entirely on this specialized filtering system.