Females are slightly bigger. Both males and females weigh up to 30,000 kg. These enormous animals eat large quantities of tiny animals. Scientists believe an adult gray whale consumes about 1,200 kg of food per day. The main component of their diet is small, shrimp-like animals called amphipods that live on muddy ocean floors.
Amphipods are minute compared to gray whales.
Gray whales use suction to draw food into their mouths. A feeding gray whale turns so that one side of its mouth faces the ocean bottom. When the whale opens its mouth slightly and pulls in its huge tongue. This draws in sediment and amphipods from the ocean bottom. The whale then pushes the sediment through the baleen plates on the opposite side of its mouth.