The blue whale (Balaenoptera musculus) is the largest animal known to have ever existed, reaching lengths of up to 100 feet and weights nearing 200 tons. This immense size requires a specialized feeding apparatus to process the tons of food needed to sustain it. The blue whale’s mouth reveals a system designed not for grasping and tearing, but for efficient filtration on an enormous scale, representing an evolutionary divergence from many large ocean predators.
The Factual Answer: Zero Teeth
The definitive answer to how many teeth a blue whale possesses is zero. Blue whales belong to the suborder Mysticeti, known as baleen whales, distinguishing them from their relatives, the Odontocetes, or toothed whales. Although blue whale embryos temporarily develop tooth buds, these are reabsorbed before birth. Instead of teeth for seizing or chewing prey, the blue whale’s upper jaw is lined with hundreds of stiff plates that facilitate filter feeding. This structure replaces the function of teeth, allowing the whale to process its primary diet of tiny organisms.
Anatomy and Structure of Baleen
Baleen is the structure that serves as the blue whale’s feeding mechanism, consisting of a series of flexible plates hanging from the roof of the mouth. Baleen is composed of keratin, the same fibrous protein found in human hair and fingernails. A single blue whale has between 270 and 395 pairs of these black plates lining its upper jaw. These plates are set close together, run perpendicular to the jawline, and can be up to three feet in length.
The inner edge of each baleen plate is frayed into a dense mat of fine, hair-like bristles facing inward toward the tongue. As the whale feeds, the friction of the tongue against the plates wears down the inner edges, continuously refreshing this fibrous curtain. This interwoven fringe creates a highly effective sieve, forming a colossal filter apparatus inside the whale’s mouth.
How Blue Whales Use Baleen to Feed
Blue whales utilize a technique called lunge feeding to consume their prey. This process begins when the whale targets a dense concentration of krill, which forms the bulk of its diet. The whale accelerates toward the swarm with its mouth open, engulfing an enormous volume of water and prey in a single gulp. To accommodate this massive intake, the blue whale possesses 55 to 88 long, expandable throat pleats that allow the lower jaw and throat to balloon outward.
Once the mouth is full, the whale begins filtration by contracting the throat pleats and using its enormous tongue to push the trapped water back out. The water is forced through the narrow gaps between the baleen plates. The dense, interwoven mat of bristles acts as a strainer, trapping the krill inside the mouth. The whale then swallows the concentrated mass of food, enabling a single adult to consume up to eight tons of krill per day.