Bubble net feeding feed in a short amount of time. Humpback whales have a vertical throat roughly the size of a grapefruit. They cannot physically swallow anything larger than that. They are carnivores and primarily feed on small fish such as krill, juvenile salmon, and herring. They are also baleen whales, which means that they do not have teeth, so they must be able to eat things that they can swallow whole. They have several vertical grooves running down the length of their body so that they can hold large volumes of water and fish at one time. They feed for up to
Baleen whale toothed cetaceans (Archaeoceti) remained unknown until the extinct "Janjucetus hunderi" was discovered in the early 1990s in Victoria, Australia. Like a modern baleen whale, "Janjucetus" had baleen in its jaw and had very little biosonar capabilities. However, its jaw also contained teeth, with incisors and canines built for stabbing and molars and premolars built for tearing. These early mysticetes were exceedingly small compared to modern baleen whales, with species like "Mammalodon" measuring no greater than . It is thought that their size increased with their dependence on baleen. However, the discovery of a skull of the toothed "Llanocetus", the second-oldest