The females are slightly larger than males, as with all baleen whales. These markings are unique to each individual whale, like a fingerprint. The humpback's skin is freqently scarred and may have patches covered with diatoms. They have round bumps on the top of the head and on the edge of the flippers. The flippers may have barnacles growing on them.
Humpbacks have a small dorsal fin toward the flukes.
Humpback whales have 14-35 throat grooves that run from the chin to the navel. These grooves allow their throat to expand during the huge intake of water during filter feeding. Concentrated massses of prey are preferrable for this method of feeding. They eat twice a day. Humpbacks cooperate in hunting and have developed a method of rounding up highly concentrated masses of prey that is called bubble-net feeding.