Baleen in throat of bowhead whale traps prey by tangling fringed edges together.

The bowhead whale feeds by entangling prey in plates in its throat, called baleen. These plates are comprised of three layers of keratin (the same in human fingernails) – two smooth layers on the outside with a fibrous layer between. Individual fringed edges of the baleen interact with one another as water passes through and over them, causing them to tangle. As they tangle, a net-like structure is formed that captures food.

Water flow rates impact the ability of the fringed baleen edges to interact. Too much water flowing through the whale’s mouth causes distortion and allows material to pass through rather easily due to little interaction between the edges; too little water does not allow the edges to interact at all and thus, prevents tangling and proper prey capture. Baleen plates are oriented in the whale’s mouth perpendicular to water flow, increasing fringe interaction and improving material capture regardless of flow rate. The baleen material is extremely strong, yet flexible, withstanding powerful forces of water flow and ocean pressure.

Baleen length, diameter, and density differ between different whales, aligning with divergent feeding styles. Humpback whales, which conduct long dives to capture small fish, possess wider baleen fringes. In contrast, bowhead whales skim for microscopic prey and exhibit longer, denser fringes.

Last Updated August 23, 2016