Baleen in unique epidermal modification of the mouth (upper jaw) of certain whales. Those giant combs, 2 rows of plates with coarse broomlike bristles are made of keratin that filter millions of liters of water a day. Like humans, whales cannot drink saltwater. Hairs on the baleen plates catch the fish or plankton, while the saltwater washes through and goes back into the ocean.
They filter these food out of the water; with each mouthful of water, these whales can filter out thousands of prey items, sometimes taking in 4 tons of food each day.
There are 11 types of baleen whales divided into 4 different families:
- Family Eschrichtiidae, which is just the gray whale
- Family Balaenopoteridae, which includes the humpback, blue, fin, sei, Bryde’s and minke whales. These whales are also known as rorqual whales
- Family Balaenidae, which includes the bowhead, the northern right and the southern right whales
- Family Neobalaenidae, which is the pygmy right whale.