Baleen whale

The baleen whales, also called whalebone whales or great whales, form the Mysticeti, one of two suborders of the Cetacea (whales, dolphins and porpoises). Baleen whales are characterized by having baleen plates for filtering food from water, rather than having teeth. This distinguishes them from the other suborder of cetaceans, the toothed whales or Odontoceti. Living Mysticeti species have teeth only during the embryonal phase. Fossil Mysticeti had teeth before baleen evolved.

Baleen whales are generally larger than toothed whales, and females are larger than males. This group comprises the largest living animal species. Baleen whales have two blowholes, causing a V-shaped blow.

The suborder contains four families and fourteen species. A list of species can be found below and at the Cetacea article. The scientific name derives from the Greek word mystax, which means "moustache".

Feeding

Baleen whales do not have teeth; instead they have baleen in the upper jaw. They engulf sea water containing crustaceans, then close their mouth and create internal pressure by raising their tongue toward the palate to push the water out through the 'comb' of baleen plates, trapping small ocean animals, especially krill and plankton, inside.

This is called filter feeding, and is also used by flamingos. Even though individually the crustaceans are minuscule, baleen whales take in an enormous volume of water containing them to maintain their survival.

There are several types of food-finding methods:

Gulpers (swallowers): alternate between swimming and opening their mouths, e.g. Blue Whales, Pygmy Blue Whales, Fin Whales, Bryde's Whales, Humpback Whales, and Minke Whales.
Skimmers: predominantly have their mouths open while swimming, e.g. right whales, Pygmy Right Whales, and Bowhead Whales
Benthic feeders: Gray Whales
Combined: Sei Whales are both swallowers and skimmers

Behaviour

Movement

Baleen whales live in all oceans. All species travel seasonally. They spend the summer in cold waters in high latitudes, where they feed. In autumn they move to warmer waters to mate and give birth. Except in their feeding grounds, baleen whales eat little or fast for months. The Gray Whale travels the longest migratory route of all mammals.

Breaching

In spite of their enormous mass, baleen whales are able to leap completely out of the water. Known for their acrobacy are the Humpback Whales, but other baleen whales also break through the water surface with their body or beat it loudly with their fins. The reason for these habits is not known for certain, and they may serve several purposes. In breaching, whale flukes often can be used as identifying markings, as is the case for Humpback Whales. This is the method by which the publicized errant Humphrey the whale was identified in three separate sightings.

Sound

In contrast to toothed whales, baleen whales are unlikely to echo-locate. Instead they are able to produce high volume sounds in the infrasonic range. The calls of the largest whales can be heard several hundreds of kilometers away. Unique are the songs of the Humpback Whales, consisting of complex sequences that may slowly evolve over years. They are probably used for courting. See the whale song article for a fuller description.

Miscellaneous

In the 19th and early 20th centuries, baleen whales were hunted for their oil and baleen. Their oil can be made into margarine and cooking oils. The function of baleen can be found in the baleen article.

Taxonomic classification

ORDER CETACEA
- Suborder Mysticeti: Baleen whales
  - Family Balaenidae: Right whales and Bowhead Whale
    - Genus Balaena
      - Bowhead Whale, Balaena mysticetus
    - Genus Eubalaena
      - Atlantic Northern Right Whale, Eubalaena glacialis
      - Pacific Northern Right Whale, Eubalaena japonica
      - Southern Right Whale, Eubalaena australia
  - Family Balaenopteridae: Rorquals
    - Subfamily Balaenopterinae
      - Genus Balaenoptera
        Fin Whale, Balaenoptera physalus
        Sei Whale, Balaenoptera borealis
        Bryde's Whale, Balaenoptera brydei
        Pygmy Bryde's Whale, (Eden's Whale) Balaenoptera edeni
        Blue Whale, Balaenoptera musculus
        Northern Minke Whale, Balaenoptera acutorostrata
        Southern Minke Whale, (Antarctic Minke Whale) Balaenoptera bonaerensis
        Balaenoptera omurai, discovery announced November 2003. No common name yet in usage
    - Subfamily Megapterinae
      - Genus Megaptera
        Humpback Whale, Megaptera novaeangliae
  - † Genus Eobalaenoptera
    - † Eobalaenoptera harrisoni, fossil species first discovered June 2004. No common name.
  - Family Eschrichtiidae
    - Genus Eschrichtius
      - Gray Whale, Eschrichtius robustus
  - Family Neobalaenidae: Pygmy Right Whale
    - Genus Caperea
      - Pygmy Right Whale, Caperea marginata

Baleen whales