baleen whales are the largest family in the suborder baleen whales, including nine species of baleen whales belonging to two genera. Among them, the blue whale, the largest animal in the world at present, weighs more than 1.51 metric tons, and the two kinds of minke whales with the second largest body often exceed 51 metric tons. Even the smallest minke whale in the undergraduate course can weigh more than 9 metric tons.

origin of common name

members of rorqual baleen family are usually collectively referred to as "rorqual" in English. This name evolved from Norwegian, meaning "furrow whale", because they have a common point: there are many long furrow-like skin folds from the mandible to the navel, which are called laryngeal and abdominal folds. Gray whales belonging to the suborder baleen whales, as well as some beaked whales belonging to the suborder odontocida, also have structures similar to throat and abdomen folds, but the former has only four simple folds, which are far from dozens to nearly a hundred of baleen whales in number; The so-called "throat and abdomen fold" of beaked whales is only a V-shaped groove on each cheek.

minke

Minke whales are usually called "minke" in English. The origin of this name may be related to Meincke, a Norwegian or German whaling gunner. It is said that in a whaling operation in the early 21th century, minke whales were mistaken for blue whales and killed. Another theory was that the whaling crew thought they were too small to catch, and "minke" was a joke he blurted out at that time.

distribution

baleen whales are widely distributed in the sea areas all over the world. Blue whales, fin whales, humpback whales, plug whales, minke whales, etc. may be found in all oceans, while Brucella whales are special. It seems that they do not appear in the cold waters around the North Pole or South Pole, but stay in warm and tropical areas all year round. Most baleen whales of baleen family live in the ocean and rarely get close to the coast. The only exceptions are Brucella and Megaptera: the former can usually be found near the coast all year round, while the latter often gets close to the shore during the annual migration from north to south.

only the largest and smallest species in the family baleen whales-blue whales and minke whales-swim to the cold waters at the southern tip of the Antarctic. Fin whales usually don't approach the Antarctic ice shelf area, while plug whales range farther north. (In the northern hemisphere, due to the large land area, it has a strong influence on climate and ocean currents, and the above situation is less obvious. No matter what kind of baleen whale it is, generally speaking, larger individuals tend to approach the polar region, while younger whales mostly stay in the south (or north).

migration

most baleen whales breed in warm and tropical seas in winter and feed on abundant plankton and krill at the poles in summer, so they have to make long-distance north-south migration every year. Brucella whales are the only exception in the baleen family. It seems that there is no obvious division between feeding period and breeding season, and some populations may not even be migratory.

Feeding patterns

The feeding habits of various baleen whales are different. For example, blue whales only feed on krill, while Brucella whales mainly feed on small fish. The feeding behavior of baleen whales is sometimes described as "gulper", because their feeding way is to swallow a large amount of seawater at a time with an open mouth. At this time, they will increase the volume of their mouth by expanding their throat and abdomen, and then close their mouths to spit out the water, so that the food contained in the seawater will be blocked by the baleen and remain in their mouths.

There are 3 families of baleen whales in the world, including Right Whale Family, Gray Whale Family and Fin Whale Family, with about 6 genera and 11 species.

baleen whales are huge, and the smallest species is more than 6 meters long. There are no teeth in the mouth, only degenerated teeth can be seen during embryonic development, but there are 151-411 comb-like horny whiskers on the left and right sides of the maxilla from the palate to the pharynx. The color, shape and number of whiskers vary with different species, which is one of the important basis for classification. There are two external nostrils, located on the top of the head, which can eject two water columns when breathing. The skull is huge, and some species can reach 1/3 of the body length, which is symmetrical. Cervical spine healing or separation. The sternum is small, only 1? /FONT> Two pairs of ribs are connected to the sternum, and the thorax is incomplete. No collarbone. The flippers generally have four fingers. There is a cecum in the digestive tract. They mainly feed on small crustaceans such as krill, and some species also eat small group fish, as well as benthic fish and shellfish.

There are not many species of baleen whales. There are 9 species found in China, and they have been found in China, such as blue whales, fin whales, large-winged whales, right whales and gray whales.