Do blue whales, the largest animals on Earth, possess teeth? While many large marine predators rely on sharp teeth for hunting, blue whales have evolved a unique feeding method. This article explores the anatomy of their mouth and explains how they thrive without teeth.
The Blue Whale’s Unique Mouth
Blue whales possess hundreds of flexible, comb-like structures called baleen plates instead of teeth. Made of keratin, the same protein found in human fingernails and hair, these dark plates hang in two rows from the upper jaw, resembling fringed curtains.
Each baleen plate can measure up to three feet long, with a single whale having 260 to 400 plates on each side of its mouth. The inner edge of each plate frays into fine bristles, forming a dense, fibrous mat. This structure is designed for efficient filtration.
How Blue Whales Eat
Blue whales are filter feeders, primarily consuming tiny, shrimp-like crustaceans called krill. To capture these organisms, they employ “lunge feeding,” locating dense krill swarms often by using their hearing to detect prey sounds.
Once a krill patch is identified, the whale accelerates and opens its massive mouth, engulfing an enormous volume of water and krill. Its throat pleats, large grooves along its underside, expand to accommodate this influx. The water volume taken in during a single lunge can exceed the whale’s own body weight.
After engulfing water and krill, the whale closes its mouth and uses its tongue to push the water out. As water expels, the baleen plates act as a sieve, trapping krill within the mouth. The baleen’s fine bristles prevent the crustaceans from escaping. The whale then scrapes the concentrated krill off the plates with its tongue and swallows them. An adult blue whale can consume up to four tons of krill daily.
Baleen Whales vs. Toothed Whales
Not all whales are toothless. The order Cetacea, which includes whales, dolphins, and porpoises, divides into two suborders based on feeding anatomy. Blue whales belong to Mysticeti, or baleen whales. This group includes humpback, right, and gray whales, all filter feeders relying on baleen plates to strain small organisms from water.
The other suborder is Odontoceti, or toothed whales, including species like orcas, sperm whales, and dolphins. These whales possess teeth and employ active predatory strategies. They use their teeth to grasp and tear larger prey such as fish, squid, and marine mammals. Many also utilize echolocation, emitting sound waves and interpreting echoes to locate prey in the ocean depths.
The distinct feeding mechanisms of baleen and toothed whales reflect different evolutionary paths and ecological niches. Baleen whales consume vast quantities of small organisms, playing a significant role in marine food webs by transferring energy from lower to higher trophic levels. Toothed whales, as apex predators, control prey populations. Both adaptations allow these diverse marine mammals to thrive in various ocean environments.