Also called ventral grooves. Accordion-like folds of skin and blubber on the underside of rorqual whales, from the tip of the lower jaw all the way down to the stomach. These folds expand and allow the whale to engulf a massive amount of water at once, effectively entrapping large amounts of their food (krill and small fish). When the whale closes its mouth, the ventral pleats contract, pushing water out while the prey is filtered by the baleen plates.























































































































