Усатые киты семейства полосатиковых

Family of mammals

Rorquals ('/r//ɔr//k//w//əl//z/) are the largest group of baleen whales, comprising the family Balaenopteridae, which contains ten extant species in three genera. They include the largest known animal that has ever lived, the blue whale, which can reach , and the fin whale, which reaches ; even the smallest of the group, the northern minke whale, reaches
Rorquals take their name from French rorqual, which derives from the Norwegian word : the first element røyr originated from the Old Norse name for this type of whale, reyðr, probably related to the Norse word for "red", and the second from the Norse word hvalr meaning "whale" in general. The family name Balaenopteridae is from the type genus, Balaenoptera.

All members of the family have a series of longitudinal folds of skin running from below the mouth back to the navel (except the sei whale and common minke whale, which have shorter grooves). These furrows allow the mouth to expand immensely when feeding. These "pleated throat grooves" distinguish balaenopterids from other whales. Gestation in rorquals lasts 11–12 months, so that both mating and birthing occur at the same time of year. Cows give birth to a single calf, which is weaned after 6–12 months, depending on species. Rice's whale has the smallest distribution of rorquals and possibly baleen whales in general, being endemic to a small portion of the Gulf of Mexico west of the Florida peninsula and south of Alabama and the Florida panhandle, although it likely formerly had a much wider distribution in the Gulf. Most rorquals are strictly oceanic: the exceptions are the gray whale, Bryde's whale, Eden's whale, and Rice's whale (which are usually found close to shore all year round) and the humpback whale (which is oceanic but passes close to shore when migrating). It is the largest and the smallest types — the blue whale and Antarctic minke whale — that occupy the coldest waters in the extreme south; the fin whale tends not to approach so close to the ice shelf; the sei whale tends to stay further north again. (In the northern hemisphere, where the continents distort weather patterns and ocean currents, these movements are less obvious, although still present.) Within each species, the largest individuals tend to approach the poles more closely, while the youngest and fittest ones tend to stay in warmer waters before leaving on their annual migration. Most rorquals breed in tropical waters during the winter, then migrate back to the polar feeding grounds rich in plankton and krill for the short polar summer.

As well as other methods, rorquals obtain prey by lunge feeding on bait balls. Lunge feeding is an extreme feeding method, where the whale accelerates to a high velocity and then opens its mouth to a large gape angle. This generates the water pressure required to expand its mouth and engulf and filter a huge amount of water and fish. Furthermore, their large nerves are flexible so that they can stretch and recoil. In fact, they give rorquals the ability to open their mouths so wide that they would be capable of taking in water at volumes greater than their own sizes.