Species that live in polar habitats are vulnerable to the effects of ongoing climate change, particularly declines in sea ice, as well as ocean acidification. Sexual dimorphism is usually reversed, with the males being larger, but the females of all baleen whales are usually five percent larger than males.  The whale lungs are very efficient at extracting oxygen from the air, usually 80%, whereas humans only extract 20% of oxygen from inhaled air. Intelligence tests such as the mirror test cannot be done because their bulk and lack of body language makes a reaction impossible to be definitive. JARPA mainly caught Antarctic minke whales, catching nearly 7,000; to a far lesser extent, they also caught fin whales. , Most species of baleen whale migrate long distances from high latitude waters during spring and summer months to more tropical waters during winter months. Along with the North Atlantic right whale, the North Pacific … The first compartment is known as the fore-stomach; this is where food gets ground up into an acidic liquid, which is then squirted into the main stomach. Like other mammals, their brain has a large, folded cerebrum, the part of the brain responsible for memory and processing sensory information. All modern mysticetes are obligate filter feeders, using their baleen to strain small prey items (including small fish, krill, copepods, and zooplankton) from seawater.  The Southern right whale was hunted to near extinction in the mid-to-late 20th century, with only a small (unknown) population around Antarctica. This occurred in 2014 during the sardine run when a shiver of dusky sharks attacked a humpback whale calf. Antarctic minke whales, as their name suggests, are typically found off Antarctica in the summer and closer to the equator (e.g., around South America, Africa, and Australia) in the winter. is an archaic word for "whale", which came from Old French baleine, derived from the Latin word balæna, derived itself from the Ancient Greek φάλλαινα (phállaina).  Miocene baleen whales were preyed upon by larger predators like killer sperm whales and Megalodon.  However, there is some discussion as to whether the gray whale should be classified into its own family, or as a rorqual.,, The taxonomic name "Mysticeti" (/ˌmɪstɪˈsiːtaɪ/) apparently derives from a translation error in early copies of Aristotle's Historia Animalium (in Ancient Greek), in which "ὁ μῦς τὸ κῆτος" (ho mus to kētos, "the mouse, the whale so called") was mistakenly translated as "ὁ μυστικῆτος" (ho mustikētos, "the Mysticetus"), which D. W. Rice (of the Society for Marine Mammalogy) in his 1998 work assumed was an ironic reference to the animals' great size. The fin whale is the second-largest animal in the world, with a mass greater even than any dinosaur. Slower whales must fight the pod alone or with a small family group. Researchers using passive acoustic recordings of whale calls to track their movements have found that four of the six baleen whale species found in the western North Atlantic Ocean -- … These may control air flow and cause vibrations. When it reaches sexual maturity after 5–10 years, it will be 20 to 24 m (66 to 79 ft) long and possibly live as long as 80–90 years.  The Mito Aquarium in Numazu, Shizuoka, Japan, housed three minke whales in the nearby bay enclosed by nets. Baleen definition is - a horny keratinous substance found in two rows of transverse plates which hang down from the upper jaws of baleen whales. , The lunge-feeders are the rorquals. National Oceanic and Atmospheric Administration/U.S.  In baleen whales, it is thought that enlarged mouths adapted for suction feeding evolved before specializations for bulk filter feeding.  The mandible is connected to the skull by dense fibers and cartilage (fibrocartilage), allowing the jaw to swing open at almost a 90° angle.  Baleen whales are cetaceans classified under the parvorder Mysticeti, and consist of four extant families: Balaenidae (right whales), Balaenopteridae (rorquals), Cetotheriidae (pygmy right whale), and Eschrichtiidae (gray whale). , Commercial whaling was historically important as an industry well throughout the 19th and 20th centuries. This feeding behavior allows them to grow very big and bulky, without the necessity for a streamlined body. This humongous animal can live for up to 90 years and grows to almost 100 feet long, making it the largest animal to have ever lived on earth. Baleen whales have two blowholes, which in right whales produce a distinctive V-shaped blow, the spout of water spray and vapour blown out when the whale surfaces to breathe. Many baleen whales migrate annually, travelling long distances between cold water feeding areas and warm water breeding areas.  The penis on a right whale can be up to 2.7 m (8.9 ft) – the testes, at up to 2 m (6.6 ft) in length, 78 cm (2.56 ft) in diameter, and weighing up to 238 kg (525 lb), are also the largest of any animal on Earth. The muscular wall of the ventricle, which is responsible for pumping blood out of the heart, can be 7.6 to 12.7 centimeters (3 to 5 in) thick. Many baleen whales migrate annually, travelling long distances between cold water feeding areas and warm water breeding areas. , The whale-watching industry and anti-whaling advocates argue that whaling catches "friendly" whales that are curious about boats, as these whales are the easiest to catch. All mammals sleep, but whales cannot afford to become unconscious for long because they may drown.  Baleen whales are promiscuous, with none showing pair bonds. Baleen whales appear to have limited color vision, as they lack S-cones.  When diving, their heart rate will drop to 4 to 15 bpm to conserve oxygen. It is the smallest species of the rorquals and the second smallest species of baleen whale.Although first ignored by whalers due to its small size and low oil yield, it began to be exploited by various countries beginning in the early 20th century. Baleen whales make up one of two whale suborders within the cetacean family. Whale lice eat dead skin, resulting in minor wounds in the skin.  The initial evolution of baleen and filter feeding long preceded the evolution of gigantic body size, indicating the evolution of novel feeding mechanisms did not cause the evolution of gigantism. In a 2007 study, it was discovered that the larynx had U-shaped folds which are thought to be similar to vocal cords. The scars on male whales suggest they fight for the right to mate with females during breeding season, somewhat similar to lek mating.  Cetaceans (whales, dolphins, and porpoises) and artiodactyls are now classified under the order Cetartiodactyla, often still referred to as Artiodactyla (given that the cetaceans are deeply nested with the artiodactyls). All species were exploited, and as one type's stock depleted, another type was targeted.  Gigantism also was preceded by divergence of different mysticete lineages, meaning multiple lineages arrived at large size independently. Prey must occur in sufficient numbers to trigger the whale's interest, be within a certain size range so that the baleen plates can filter it, and be slow enough so that it cannot escape. The North Atlantic right whale got its name from whalers, who thought it was the "right" whale to hunt because it moves slowly and floats to the surface when killed. Pools of proper size would also be very expensive to build. Before weaning, the calf increases its body weight by 17 t (17 long tons; 19 short tons) and grows from 7 to 8 m (23 to 26 ft) at birth to 13 to 16 m (43 to 52 ft) long. , Unlike their toothed whale counterparts, baleen whales are hard to study because of their immense size. Unlike most other marine mammals, female baleen whales are larger than males. , Baleen whales have rarely been kept in captivity. In 1864, it was moved into the genus Caperea after a skull of another specimen was discovered. The Humpback is less slender than the other baleen whales.  Species like Mammalodon colliveri had little to no baleen, while later species like Aetiocetus weltoni had both baleen and teeth, suggesting they had limited filter feeding capabilities; later genera like Cetotherium had no teeth in their mouth, meaning they were fully dependent on baleen and could only filter feed. Commonly exploited species included arctic whales such as the gray whale, right whale, and bowhead whale because they were close to the main whaling ports, like New Bedford. , Foraging efficiency for both lunge feeding and continuous ram filter feeding is highly dependent upon prey density.
2020 baleen whale species