Hobbies And Interests
Baleen Whales
All whales in the baleen-whale category have a baleen, which is a sieve-like structure in their upper jaw. The baleen, which replaces teeth, is made up of a strong protein called keratin. The keratin grows in plates, which filter plankton, krill and small fish from the seawater. Whales will digest the sea life in large quantities, sometimes producing an animal that weighs more than a hundred tons, like the blue whale. The same blue whale needs to consume four tons of nutrients per day to stay healthy.
Types of Feeders
Baleen whales sometimes are classified by their feeding methods. Feeding groups include swallowers (or gulpers), skimmers and bottom feeders (also called benthic feeders). Bottom feeders get their nutrients by vacuuming mud off the bottom of the ocean floor in order to obtain food. The gray whale is a bottom feeder. Skimmers cruise the ocean's surface with their mouths open all the time, filtering food as they go. Swallowers alternate between swimming and swallowing food and, therefore, they seek feeding areas that have large concentrations of food so that they can gulp down a big mouthful at one time. In the natural world, right whales and bowhead whales are skimmers while blue, humpback, minke and fin whales are swallowers.
Food Quantity
Baleen whales are much larger than toothed whales, dolphins and porpoises. In order to consume the nutrients necessary to reach and maintain such a large size, these whales must take in huge amounts of nutrient-rich food. To accomplish this feat, these marine mammals have developed a baleen and are able to consume large amounts of food as they swim through nutrient-rich waters. Conversely, dolphins, porpoises and killer whales must hunt and kill prey to survive.
Plankton
Phytoplankton are one-celled organisms, similar to algae in that they are able to use the sun's energy to produce a protein-rich biomass. These microscopic life forms have been called the vegetation of the sea, because each cell stores starches and sugars created during photosynthesis. In a sense, whales are the grazers of the sea, because they eat large quantities of phytoplankton to obtain high concentrations of food. Since whales also consume krill and tiny fish, these large mammals would be more correctly labeled as omnivores -- animals that eat both meat and green plants.