Right whales or black whales are three species of large baleen whales of the genus Eubalaena: the North Atlantic right whale (E. glacialis), the North Pacific right whale (E. japonica) and the Southern right whale (E. australis). They are classified in the family Balaenidae with the bowhead whale. Right whales have rotund bodies with arching rostrums, V-shaped blowholes and dark gray or black skin. The most distinguishing feature of a right whale is the rough patches of skin on its head, which appear white due to parasitism by whale lice. Right whales can grow up to more than 18 m (59 ft) long with a highest-recorded length of 19.8 m (65 ft). Right whales are very robust whales, weighing 100 short tons (91 t; 89 long tons) or more. The largest known right whales can attain 20.7 m (68 ft) in length and weigh up to 135,000 kg (298,000 lb) or 21.3 m (70 ft) with uncertainty, Their immense bulk makes right whale significantly heavier than other whales of similar or greater length such as the humpback, gray, sperm and even fin whales. In fact, right whales rank only behind the blue whale in sheer body mass. One (apocryphal) explanation for their name is that whalers identified them as the "right" whale to kill on a hunt due to the plentiful oil and baleen they could provide.
All three species are migratory, moving seasonally to feed or give birth. The warm equatorial waters form a barrier that isolates the northern and southern species from one another although the southern species, at least, has been known to cross the equator. In the Northern Hemisphere, right whales tend to avoid open waters and stay close to peninsulas and bays and on continental shelves, as these areas offer greater shelter and an abundance of their preferred foods. In the Southern Hemisphere, right whales feed far offshore in summer, but a large portion of the population occur in near-shore waters in winter. Right whales feed mainly on copepods but also consume krill and pteropods. They may forage the surface, underwater or even the ocean bottom. During courtship, males gather into large groups to compete for a single female, suggesting that sperm competition is an important factor in mating behavior. Although the blue whale is the largest animal on the planet, the testes of the right whale are actually ten times larger than those of the blue whale – with each weighing up to 525 kilograms (1,157 lb), they are by far the largest of any animal on Earth. Gestation tends to last a year, and calves are born at 1 short ton (0.91 t; 0.89 long tons) in weight and 4–6 m (13–20 ft) in length. Weaning occurs after eight months.
Right whales were a preferred target for whalers because of their docile nature, their slow surface-skimming feeding behaviors, their tendency to stay close to the coast, and their high blubber content (which makes them float when they are killed, and which produced high yields of whale oil). Today, the North Atlantic and North Pacific right whales are among the most endangered whales in the world, and both species are protected in the United States by the Endangered Species Act. The western populations of both are currently endangered, with their total populations numbering in the hundreds. The eastern North Pacific population, on the other hand, with fewer than 50 individuals remaining, is critically endangered – further still, the eastern North Atlantic population, which numbers in the low teens at best, may already be functionally extinct.
Although the whales no longer face a threat from whaling, mankind remains by far the greatest threat to these species: the two leading causes of death are being struck by ships and entanglement in fishing gear. For the North Atlantic right whale, for example, whose population was estimated at 411 in 2018 which was down from 451 in 2016 and 458 in 2015, these two anthropogenic factors alone account for 48% of all known right whale deaths since 1970. More than 85% of right whales have been entangled at least once.
In 2017, at least 118 right whales were in the Gulf of St Lawrence, or roughly a quarter of the local population, which previously fed in summer and fall months in the Bay of Fundy and Roadway basin. The habitat shift moved this population away from existing conservation efforts and into the path of busy shipping lanes and also snow crab fisheries where Fisheries and Oceans Canada doubled the quotas in 2017.
Temporal range: Miocene-recent
|Southern right whale breaching|
|Size compared to an average human|
E. glacialis ranges
E. australis range
E. japonica range
A popular explanation for the name right whales is that they were the right ones to hunt, as they float when killed and often swim within sight of shore. They are quite docile and do not tend to shy away from approaching boats. As such, they were hunted nearly to extinction during the active years of the whaling industry. This origin is apocryphal. In his history of American whaling, Eric Jay Dolin writes:
Despite this highly plausible rationale, nobody actually knows how the right whale got its name. The earliest references to the right whale offer no indication why it was called that, and some who have studied the issue point out that the word "right" in this context might just as likely be intended "to connote 'true' or 'proper,' meaning typical of the group."— E.J. Dolin, Leviathan: The History of Whaling in America, quoting a 1766 Connecticut Courant newspaper article.
The right whales were first classified in the genus Balaena in 1758 by Carl Linnaeus, who at the time considered all of the right whales (including the bowhead) as a single species. Through the 1800s and 1900s, in fact, the family Balaenidae has been the subject of great taxonometric debate. Authorities have repeatedly recategorized the three populations of right whale plus the bowhead whale, as one, two, three or four species, either in a single genus or in two separate genera. In the early whaling days, they were all thought to be a single species, Balaena mysticetus. Eventually, it was recognized that bowheads and right whales were in fact different, and John Edward Gray proposed the genus Eubalaena for the right whale in 1864. Later, morphological factors such as differences in the skull shape of northern and southern right whales indicated at least two species of right whale—one in the Northern Hemisphere, the other in the Southern Ocean. As recently as 1998, Rice, in his comprehensive and otherwise authoritative classification, Marine mammals of the world: systematics and distribution, listed just two species: Balaena glacialis (the right whales) and Balaena mysticetus (the bowheads).
In 2000, two studies of DNA samples from each of the whale populations concluded the northern and southern populations of right whale should be considered separate species. What some scientists found more surprising was the discovery that the North Pacific and North Atlantic populations are also distinct, and that the North Pacific species is more closely related to the southern right whale than to the North Atlantic right whale. The authors of one of these studies concluded that these species have not interbred for between 3 million and 12 million years.
In 2001, Brownell et al. reevaluated the conservation status of the North Pacific right whale as a distinct species, and in 2002, the Scientific Committee of the International Whaling Commission (IWC) accepted Rosenbaum's findings, and recommended that the Eubalaena nomenclature be retained for this genus. A 2007 study by Churchill provided further evidence to conclude that the three different living right whale species constitute a distinct phylogenetic lineage from the bowhead, and properly belong to a separate genus.
The cladogram is a tool for visualizing and comparing the evolutionary relationships between taxa; the point where each node branches is analogous to an evolutionary branching – the diagram can be read left-to-right, much like a timeline. The following cladogram of the family Balaenidae serves to illustrate the current scientific consensus as to the relationships between the three right whales and the bowhead whale.
|The right whales, genus Eubalaena, in the family Balaenidae|
Whale lice, parasitic cyamid crustaceans that live off skin debris, offer further information through their own genetics. Because these lice reproduce much more quickly than whales, their genetic diversity is greater. Marine biologists at the University of Utah examined these louse genes and determined their hosts split into three species 5–6 thousand years ago, and these species were all equally abundant before whaling began in the 11th century. The communities first split because of the joining of North and South America. The rising temperatures of the equator then created a second split, into northern and southern groups, preventing them from interbreeding. "This puts an end to the long debate about whether there are three [Eubalaena] species of right whale. They really are separate beyond a doubt", Jon Seger, the project's leader, told BBC News.
The pygmy right whale (Caperea marginata), a much smaller whale of the Southern Hemisphere, was until recently considered a member of the Family Balaenidae. However, they are not right whales at all, and their taxonomy is presently in doubt. Most recent authors place this species into the monotypic Family Neobalaenidae, but a 2012 study suggests that it is instead the last living member of the Family Cetotheriidae, a family previously considered extinct.
Yet another species of right whale was proposed by Emanuel Swedenborg in the 18th century - the so-called Swedenborg whale. The description of this species was based on a collection of fossil bones unearthed at Norra Vånga, Sweden, in 1705 and believed to be those of giants. The bones were examined by Swedenborg, who realized they belong to a species of whale. The existence of this species has been debated, and further evidence for this species was discovered during the construction of a motorway in Strömstad, Sweden in 2009. To date, however, scientific consensus still considers Hunterius swedenborgii to be a North Atlantic right whale. According to a DNA analysis conducted by scientists, it was later confirmed that the fossil bones are actually from a bowhead whale.
Due to their familiarity to whalers over a number of centuries, the right whales have had many names. These names were used throughout the world, reflecting the fact that only one species was recognized at the time. In his novel Moby-Dick, Herman Melville writes:
Among the fishermen, the whale regularly hunted for oil is indiscriminately designated by all the following titles: The Whale; the Greenland whale; the black whale; the great whale; the true whale; the right whale. There is a deal of obscurity concerning the identity of the species thus multitudinously baptised. ... Some pretend to see a difference between the Greenland whale of the English and the Right whale of the Americans.— Melville, Moby Dick: or, The White Whale, Ch. XXXII Cetology
In fact, there was indeed a difference between the two – Melville's "Greenland whale", or "Greenland right whale", was in fact the modern-day bowhead whale, Balaena mysticetus.
Although the right whale is now officially in the genus Eubalaena, the type species for a genus remains as it was first described – in the case of Eubalaena the type species is Balaena australis Desmoulins, 1822.
Some of the species-level synonyms are:
Unlike other whales, a right whale has distinctive callosities (roughened patches of skin) on its head, along with a broad back without a dorsal fin, occasionally with white belly patches, and a long, arching rostrum, or upper jaw, that begins above the eye. The callosities appear white due to large colonies of cyamids (whale lice). Each individual has a unique callosities pattern. In 2016, a competitive effort resulted in the use of facial recognition software to derive a process to uniquely identify right whales with about 87% accuracy based on their callosities. The primary role of callosities has been considered to be protection against predators. Right whale declines might have also reduced barnacles. Right whales are very large, robust whales that can grow up to and over 18 m (59 ft) long and weigh up to 100 short tons (91 t; 89 long tons), almost as big as bowhead whales and much larger than other species with high dependencies on shallow waters. An unusually large 40% of their body weight is blubber, which is of relatively low density. Consequently, unlike many other species of whale, dead right whales tend to float. Right whales swim slowly, reaching only 5 kn (9.3 km/h) at top speed. However, they are highly acrobatic and frequently breach (jump clear of the sea surface), tail-slap and lobtail.
Adults may be between 11–18 m (36–59 ft) in length and typically weigh 60–80 short tons (54–73 t; 54–71 long tons). The most typical lengths are 13–16 m (43–52 ft). The body is extremely thick with girth as much as 60% of total body length in some cases. The tail fluke is broad (up to 40% of body length). The North Pacific species is on average the largest of the three species. The largest specimens may weigh 100 short tons (91 t; 89 long tons). Right whales have a distinctive wide V-shaped blow, caused by the widely spaced blowholes on the top of the head. The blow rises 5 m (16 ft) above the surface. Right whales have between 200 and 300 baleen plates on each side of their mouths. These are narrow and approximately 2 m (6.6 ft) long, and are covered in very thin hairs. The plates enable the whale to filter feed.
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 525 kg (1157 lbs), are also by far the largest of any animal on Earth. The blue whale may be the largest animal on the planet, yet the testicles of the right whale are ten times the size of those of the blue whale. They also exceed predictions in terms of relative size, as well – they are six times larger than would be expected on the basis of body mass. Together, the testicles make up nearly 1% of the right whale's total body weight. This strongly suggests sperm competition is important in mating, which correlates to the fact that right whales are highly promiscuous.
Many of southern right whales are seen with rolls of fats behind blowholes that northern species often lack, and these are regarded as a sign of better health condition due to sufficient nutrition supply, and could have contributed in vast differences in recovery status between right whales in the southern and northern hemisphere, other than direct impacts by mankind.
During the mating season, which can occur at any time in the North Atlantic, right whales gather into "surface-active groups" made up of as many as 20 males consorting a single female. The female has her belly to the surface while the males stroke her with their flippers or keep her underwater. The males do not compete as aggressively against each other as male humpbacks. The female may not become pregnant but she is still able to assess the condition of potential mates. The mean age of first parturition in North Atlantic right whales is estimated at between 7.5 and 9 years. Females breed every 3–5 years; the most commonly seen calving intervals are 3 years and may vary from 2 up to 21 years due to multiple factors.
Both reproduction and calving take place during the winter months. Calves are approximately 1 short ton (0.91 t; 0.89 long tons) in weight and 4–6 m (13–20 ft) in length at birth following a gestation period of 1 year. The right whale grows rapidly in its first year, typically doubling in length. Weaning occurs after eight months to one year and the growth rate in later years is not well understood—it may be highly dependent on whether a calf stays with its mother for a second year.
Respective congregation areas in the same region may function as for different objectives for whales.
Very little is known about the life span of right whales. One of the few well-documented cases is of a female North Atlantic right whale that was photographed with a baby in 1935, then photographed again in 1959, 1980, 1985, and 1992. Consistent callosity patterns ensured it was the same animal. She was last photographed in 1995 with a seemingly fatal head wound, presumably from a ship strike. By conservative estimates (e.g. she was a new mother who had just reached sexual maturity in 1935), she was nearly 70 years to more than 100 years of age, if not older. Research on the closely related bowhead whale exceeding 210 years or more suggests this lifespan is not uncommon and may even be exceeded.
The right whales' diets consist primarily of zooplankton, primarily the tiny crustaceans called copepods, as well as krill, and pteropods, although they are occasionally opportunistic feeders. As with other baleens, they feed by filtering prey from the water. They swim with an open mouth, filling it with water and prey. The whale then expels the water, using its baleen plates to retain the prey. Prey must occur in sufficient numbers to trigger the whale's interest, be large enough that the baleen plates can filter it, and be slow enough that it cannot escape. The "skimming" may take place on the surface, underwater, or even at the ocean's bottom, indicated by mud occasionally observed on right whales' bodies.
The right whales' two known predators are humans and orcas. When danger lurks, a group of right whales may cluster into a circle, and thrash their outwards-pointing tails. They may also head for shallow water, which sometimes proves to be an ineffective defense. Aside from the strongly-build tails and massive heads equipping with callosities, the sheer size of this animal is its best defense, although young calves are the most vulnerable to orca and shark attacks.
The three Eubalaena species inhabit three distinct areas of the globe: the North Atlantic in the western Atlantic Ocean, the North Pacific in a band from Japan to Alaska and all areas of the Southern Ocean. The whales can only cope with the moderate temperatures found between 20 and 60 degrees in latitude. The warm equatorial waters form a barrier that prevents mixing between the northern and southern groups with minor exclusions. Although the southern species in particular must travel across open ocean to reach its feeding grounds, the species is not considered to be pelagic. In general, they prefer to stay close to peninsulas and bays and on continental shelves, as these areas offer greater shelter and an abundance of their preferred foods.
Because the oceans are so large, it is very difficult to accurately gauge whale population sizes. Approximate figures:
Almost all of the 400 North Atlantic right whales live in the western North Atlantic Ocean. In northern spring, summer and autumn, they feed in areas off the Canadian and northeast U.S. coasts in a range stretching from New York to Newfoundland. Particularly popular feeding areas are the Bay of Fundy and Cape Cod Bay. In winter, they head south towards Georgia and Florida to give birth. There have been a smattering of sightings further east over the past few decades; several sightings were made close to Iceland in 2003. These are possibly the remains of a virtually extinct eastern Atlantic stock, but examination of old whalers' records suggests they are more likely to be strays. However, a few sightings are regular between Norway, Ireland, Spain, Portugal, the Canary Islands and even Italy and Sicily; at least the Norway individuals come from the Western stock.
The North Pacific right whale appears to occur in two populations. The population in the eastern North Pacific/Bering Sea is extremely low, numbering about 30 individuals. A larger western population of 100–200 appears to be surviving in the Sea of Okhotsk, but very little is known about this population. Thus, the two northern right whale species are the most endangered of all large whales and two of the most endangered animal species in the world. Based on current population density trends, both species are predicted to become extinct within 200 years. The Pacific species was historically found in summer from the Sea of Okhotsk in the west to the Gulf of Alaska in the east, generally north of 50°N. Today, sightings are very rare and generally occur in the mouth of the Sea of Okhotsk and in the eastern Bering Sea. Although this species is very likely to be migratory like the other two species, its movement patterns are not known.
The last major population review of southern right whales by the International Whaling Commission was in 1998. Researchers used data about adult female populations from three surveys (one in each of Argentina, South Africa and Australia) and extrapolated to include unsurveyed areas and estimated counts of males and calves (using available male:female and adult:calf ratios), giving an estimated 1997 population of 7,500 animals. More recent data from 2007 indicate those survey areas have shown evidence of strong recovery, with a population approaching twice that of a decade earlier. However, other breeding populations are still very small, and data are insufficient to determine whether they, too, are recovering.
The southern right whale spends the summer months in the far Southern Ocean feeding, probably close to Antarctica. It migrates north in winter for breeding, and can be seen around the coasts of Argentina, Australia, Brazil, Chile, Mozambique, New Zealand, South Africa and Uruguay. Since hunting of the southern right whale ceased, stocks are estimated to have grown by 7% a year. The South American, South African and Australasian groups apparently intermix very little, if at all, because of the strong fidelity of mothers to their feeding and calving grounds. The mother passes these instincts to her calves.
Vocalizations made by right whales are not elaborate compared to those made by other whale species. The whales make groans, pops and belches typically at frequencies around 500 Hz. The purpose of the sounds is not known but may be a form of communication between whales within the same group. Northern right whales responded to sounds similar to police sirens—sounds of much higher frequency than their own. On hearing the sounds, they moved rapidly to the surface. The research was of particular interest because northern rights ignore most sounds, including those of approaching boats. Researchers speculate this information may be useful in attempts to reduce the number of ship-whale collisions or to encourage the whales to surface for ease of harvesting.
In the early centuries of shore-based whaling before 1712, right whales were virtually the only catchable large whales, for three reasons:
Basque people were the first to hunt right whales commercially, beginning as early as the 11th century in the Bay of Biscay. They initially sought oil, but as meat preservation technology improved, the animal was also used for food. Basque whalers reached eastern Canada by 1530 and the shores of Todos os Santos Bay (in Bahia, Brazil) by 1602. The last Basque voyages were made before the Seven Years' War (1756–1763). All attempts to revive the trade after the war failed. Basque shore whaling continued sporadically into the 19th century.
"Yankee whalers" from the new American colonies replaced the Basques. Setting out from Nantucket, Massachusetts and Long Island, New York, they took up to 100 animals in good years. By 1750, the commercial hunt of the North Atlantic right whale was basically over. The Yankee whalers moved into the South Atlantic before the end of the 18th century. The southernmost Brazilian whaling station was established in 1796, in Imbituba. Over the next hundred years, Yankee whaling spread into the Southern and Pacific Oceans, where the Americans were joined by fleets from several European nations. The beginning of the 20th century saw much greater industrialization of whaling, and the harvest grew rapidly. By 1937, there had been, according to whalers' records, 38,000 takes in the South Atlantic, 39,000 in the South Pacific, 1,300 in the Indian Ocean, and 15,000 in the North Pacific. The incompleteness of these records means the actual take was somewhat higher.
As it became clear the stocks were nearly depleted, the world banned right whaling in 1937. The ban was largely successful, although violations continued for several decades. Madeira took its last two right whales in 1968. Japan took 23 Pacific right whales in the 1940s and more under scientific permit in the 1960s. Illegal whaling continued off the coast of Brazil for many years and the Imbituba land station processed right whales until 1973. The Soviet Union illegally took at least 3,212 southern right whales during the 1950s and '60s, although it reported taking only four.
The southern right whale has made Hermanus, South Africa one of the world centers for whale watching. During the winter months (July–October), southern right whales come so close to the shoreline, visitors can watch whales from strategically placed hotels. The town employs a "whale crier" (cf. town crier) to walk through the town announcing where whales have been seen. Southern right whales can also be watched at other winter breeding grounds.
In Brazil, Imbituba in Santa Catarina has been recognized as the National Right Whale Capital and holds annual Right Whale Week celebrations in September when mothers and calves are more often seen. The old whaling station there has been converted to a museum dedicated to the whales. In winter in Argentina, Península Valdés in Patagonia hosts the largest breeding population of the species, with more than 2,000 animals catalogued by the Whale Conservation Institute and Ocean Alliance.
Both the North Atlantic and North Pacific species are listed as a "species threatened with extinction which [is] or may be affected by trade" (Appendix I) by CITES, and as "endangered" by the IUCN Red List. In the United States, the National Marine Fisheries Service (NMFS), a subagency of the National Oceanic and Atmospheric Administration (NOAA) has classified all three species as "endangered" under the Endangered Species Act. Under the Marine Mammal Protection Act, they are listed as "depleted".
The southern right whale is listed as "endangered" under the Australian Environment Protection and Biodiversity Conservation Act, as "nationally endangered" under the New Zealand Threat Classification System, as a "natural monument" by the Argentine National Congress, and as a "State Natural Monument" under the Brazilian National Endangered Species List.
The US and Brazil added new protections for right whales in the 2000s to address the two primary hazards. While environmental campaigners were, as reported in 2001, pleased about the plan's positive effects, they attempted to force the US government to do more. In particular, they advocated 12 knots (22 km/h) speed limits for ships within 40 km (25 mi) of US ports in times of high right whale presence. Citing concerns about excessive trade disruption, it did not institute greater protections. The Defenders of Wildlife, the Humane Society of the United States and the Ocean Conservancy sued the NMFS in September 2005 for "failing to protect the critically endangered North Atlantic Right Whale, which the agency acknowledges is 'the rarest of all large whale species' and which federal agencies are required to protect by both the Marine Mammal Protection Act and the Endangered Species Act", demanding emergency protection measures. According to NOAA researchers, about 83% of right whale sightings in the mid-Atlantic region occur within 20 nautical miles (37 km) of shore.
The southern right whale, listed as "endangered" by CITES and "lower risk - conservation dependent" by the IUCN, is protected in the jurisdictional waters of all countries with known breeding populations (Argentina, Australia, Brazil, Chile, New Zealand, South Africa and Uruguay). In Brazil, a federal Environmental Protection Area encompassing some 1,560 km2 (600 sq mi) and 130 km (81 mi) of coastline in Santa Catarina State was established in 2000 to protect the species' main breeding grounds in Brazil and promote whale watching.
On February 6, 2006, NOAA proposed its Strategy to Reduce Ship Strikes to North Atlantic Right Whales. The proposal, opposed by some shipping interests, limited ship speeds during calving season. The proposal was made official when on December 8, 2008, NOAA issued a press release that included the following:
The leading cause of death among the North Atlantic right whale, which migrates through some of the world's busiest shipping lanes while journeying off the east coast of the United States and Canada, is being struck by ships.[note 1] At least 16 ship-strike deaths were reported between 1970 and 1999, and probably more remain unreported. According to NOAA, 25 of the 71 right whale deaths reported since 1970 resulted from ship strikes.
A second major cause of morbidity and mortality in the North Atlantic right whale is entanglement in plastic fishing gear. Right whales ingest plankton with wide-open mouths, risking entanglement in any rope or net fixed in the water column. Rope wraps around their upper jaws, flippers and tails. Some are able to escape, but others remain tangled. Whales can be successfully disentangled, if observed and aided. In July 1997, the U.S. NOAA introduced the Atlantic Large Whale Take Reduction Plan, which seeks to minimize whale entanglement in fishing gear and record large whale sightings in an attempt to estimate numbers and distribution.
In 2012, the U.S. Navy proposed to create a new undersea naval training range immediately adjacent to northern right whale calving grounds in shallow waters off the Florida/Georgia border. Legal challenges by leading environmental groups including the Natural Resources Defense Council were denied in federal court, allowing the Navy to proceed. These rulings were made despite the extremely low numbers (as low as 313 by some estimates) of right whales in existence at this time, and a very poor calving season.
The western North Atlantic population numbered at least 361 individuals in 2005 and at least 396 in 2010 (Waring et al. 2012).
The placement of Caperea within the monotypic Family Neobalaenidae is done with the qualification that future work may corroborate the referral of Caperea to the † Family Cetotheriidae.
The true buoyancy of a particular whale is dependent upon its body composition, particularly the relative quantities of muscle and blubber tissues. Balaenopterid whales have a higher proportion of muscle tissue and tend to be negatively buoyant while the opposite is true for right whales (Lockyer, 1976).
Balaenidae is a family of whales of the parvorder Mysticeti that contains two living genera: the right whales (genus Eubalaena), and in a separate genus, the closely related bowhead whale (genus Balaena).Baleen whale
Baleen whales (systematic name Mysticeti), known earlier as whalebone whales, form a parvorder of the infraorder Cetacea (whales, dolphins and porpoises). They are a widely distributed and diverse parvorder of carnivorous marine mammals. Mysticeti comprise the families Balaenidae (right and bowhead whales), Balaenopteridae (rorquals), Cetotheriidae (the pygmy right whale), and Eschrichtiidae (the gray whale). There are currently 15 species of baleen whales. While cetaceans were historically thought to have descended from mesonychids, (which would place them outside the order Artiodactyla), molecular evidence supports them as a clade of even-toed ungulates (Artiodactyla). Baleen whales split from toothed whales (Odontoceti) around 34 million years ago.
Baleen whales range in size from the 20 ft (6 m) and 6,600 lb (3,000 kg) pygmy right whale to the 102 ft (31 m) and 190 t (210 short tons) blue whale, the largest known animal to have ever existed. They are sexually dimorphic. Baleen whales can have streamlined or large bodies, depending on the feeding behavior, and two limbs that are modified into flippers. Though not as flexible and agile as seals, baleen whales can swim very fast, with the fastest able to travel at 23 miles per hour (37 km/h). Baleen whales use their baleen plates to filter out food from the water by either lunge-feeding or skim-feeding. Baleen whales have fused neck vertebrae, and are unable to turn their head at all. Baleen whales have two blowholes. Some species are well adapted for diving to great depths. They have a layer of fat, or blubber, under the skin to keep warm in the cold water.
Although baleen whales are widespread, most species prefer the colder waters of the Arctic and Antarctic. Gray whales are specialized for feeding on bottom-dwelling crustaceans. Rorquals are specialized at lunge-feeding, and have a streamlined body to reduce drag while accelerating. Right whales skim-feed, meaning they use their enlarged head to effectively take in a large amount of water and sieve the slow-moving prey. Males typically mate with more than one female (polygyny), although the degree of polygyny varies with the species. Male strategies for reproductive success vary between performing ritual displays (whale song) or lek mating. Calves are typically born in the winter and spring months and females bear all the responsibility for raising them. Mothers fast for a relatively long period of time over the period of migration, which varies between species. Baleen whales produce a number of vocalizations, notably the songs of the humpback whale.
The meat, blubber, baleen, and oil of baleen whales have traditionally been used by the indigenous peoples of the Arctic. Once relentlessly hunted by commercial industries for these products, cetaceans are now protected by international law. However, the North Atlantic right whale is ranked endangered by the International Union for Conservation of Nature. Besides hunting, baleen whales also face threats from marine pollution and ocean acidification. It has been speculated that man-made sonar results in strandings. They have rarely been kept in captivity, and this has only been attempted with juveniles or members of one of the smallest species.Bowhead whale
The bowhead whale (Balaena mysticetus) is a species of the family Balaenidae, in parvorder Mysticeti, and genus Balaena, which once included the right whale.
A stocky dark-coloured whale without a dorsal fin, it can grow 14 to 18 m (46 to 59 ft) in length. This thick-bodied species can weigh from 75 to 100 tonnes (74 to 98 long tons; 83 to 110 short tons). They live entirely in fertile Arctic and sub-Arctic waters, unlike other whales that migrate to low latitude waters to feed or reproduce. The bowhead was also known as the Greenland right whale or Arctic whale. American whalemen called them the steeple-top, polar whale, or Russia or Russian whale. The bowhead has the largest mouth of any animal.The bowhead was an early whaling target. The population was severely reduced before a 1966 moratorium was passed to protect the species. Of the five stocks of bowhead populations, three are listed as "endangered", one as "vulnerable", and one as "lower risk, conservation dependent" according to the IUCN Red List. The global population is assessed as of least concern.Cephalorhynchus
Cephalorhynchus is a genus in the dolphin family Delphinidae.Cetacea
Cetaceans () (from Latin: cetus, lit. 'whale', from Ancient Greek: κῆτος, translit. kētos, lit. 'huge fish') are aquatic mammals constituting the infraorder Cetacea. There are around 89 living species, which are divided into two parvorders. The first is the Odontoceti, the toothed whales, which consist of around 70 species, including the dolphin (which includes killer whales), porpoise, beluga whale, narwhal, sperm whale, and beaked whale. The second is the Mysticeti, the baleen (from Latin: balæna, lit. 'whale') whales, which have a filter-feeder system, and consist of 15 species divided into 3 families, and include the right whale, bowhead whale, rorqual, pygmy right whale, and gray whale.
The ancient and extinct ancestors of modern whales (Archaeoceti) lived 53 to 45 million years ago. They diverged from even-toed ungulates; their closest living relatives are hippopotamuses and others such as camels and pigs. They were amphibious, and evolved in the shallow waters that separated India from Asia. Around 30 species adapted to a fully oceanic life. Baleen whales split from toothed whales around 34 million years ago.
The smallest cetacean is Maui's dolphin, at 1 m (3 ft 3 in) and 50 kg (110 lb); the largest is the blue whale, at 29.9 m (98 ft) and 173 t (381,000 lb). Baleen whales have a tactile system in the short hairs (vibrissae) around their mouth; toothed whales do not have vibrissae. Cetaceans have well-developed senses—their eyesight and hearing are adapted for both air and water. They have a layer of fat, or blubber, under the skin to maintain body heat in cold water. Several species exhibit sexual dimorphism. Two external forelimbs are modified into flippers; two internal hindlimbs are vestigial. Cetaceans have streamlined bodies: they can swim very quickly, with the killer whale able to travel at 56 kilometres per hour (35 mph) in short bursts, the fin whale able to cruise at 48 kilometres per hour (30 mph), dolphins able to make very tight turns at high speeds, and some species diving to great depths.
Although cetaceans are widespread, most species prefer the colder waters of the Northern and Southern Hemispheres. They spend their lives in the water of seas and rivers; having to mate, give birth, molt or escape from predators, like killer whales, underwater. This has drastically affected their anatomy to be able to do so. They feed largely on fish and marine invertebrates; but a few, like the killer whale, feed on large mammals and birds, such as penguins and seals. Some baleen whales (mainly gray whales and right whales) are specialised for feeding on benthic creatures. Male cetaceans typically mate with more than one female (polygyny), although the degree of polygyny varies with the species. Cetaceans are not known to have pair bonds. Male cetacean strategies for reproductive success vary between herding females, defending potential mates from other males, or whale song which attracts mates. Calves are typically born in the fall and winter months, and females bear almost all the responsibility for raising them. Mothers of some species fast and nurse their young for a relatively short period of time, which is more typical of baleen whales as their main food source (invertebrates) aren't found in their breeding and calving grounds (tropics). Cetaceans produce a number of vocalizations, notably the clicks and whistles of dolphins and the moaning songs of the humpback whale.
The meat, blubber and oil of cetaceans have traditionally been used by indigenous peoples of the Arctic. Cetaceans have been depicted in various cultures worldwide. Dolphins are commonly kept in captivity and are even sometimes trained to perform tricks and tasks, other cetaceans aren't as often kept in captivity (with usually unsuccessful attempts). Cetaceans have been relentlessly hunted by commercial industries for their products, although this is now forbidden by international law. The baiji (Chinese river dolphin) has become "Possibly Extinct" in the past century, while the vaquita and Yangtze finless porpoise are ranked Critically Endangered by the International Union for Conservation of Nature. Besides hunting, cetaceans also face threats from accidental trapping, marine pollution, and ongoing climate change.Cetotheriidae
Cetotheriidae is a family of baleen whales (suborder Mysticeti). The family is known to have existed from the Late Oligocene to the Early Pleistocene before going extinct. Although some phylogenetic studies conducted by Fordyce & Marx 2013 recovered the living pygmy right whale as a member of Cetotheriidae, making the pygmy right whale the only living cetotheriid, other authors either dispute this placement or recover Neobalaenidae as a sister group to Cetotheriidae.Ginkgo-toothed beaked whale
The ginkgo-toothed beaked whale (Mesoplodon ginkgodens) is a poorly known species of whale even for a beaked whale, and was named for the unusual shape of its dual teeth. It is a fairly typical-looking species, but is notable for the males not having any scarring .Kogia
Kogia is a genus of toothed whales within the superfamily Physeteroidea comprising two extant and one extinct species: Fossils date to the miocene
Pygmy sperm whale, Kogia breviceps
Dwarf sperm whale, Kogia sima
Kogia pusilla extinctList of cetacean species
The following is a list of existing (extant) species of the infraorder cetacea, organized taxonomically into parvorders, superfamilies when applicable, families, subfamilies when applicable, genus, and then species. In tabular form, seven descriptors are given for each species: the common name; the scientific name; the IUCN red list status; a global population estimate; a global map with its range; its weight with an image of its shape, and its size relative to a human; and a photograph.North Atlantic right whale
The North Atlantic right whale (Eubalaena glacialis, which means "good, or true, whale of the ice") is a baleen whale, one of three right whale species belonging to the genus Eubalaena, all of which were formerly classified as a single species. Because of their docile nature, their slow surface-skimming feeding behaviors, their tendencies to stay close to the coast, and their high blubber content (which makes them float when they are killed, and which produced high yields of whale oil), right whales were once a preferred target for whalers.
At present, they are among the most endangered whales in the world, and they are protected under the U.S. Endangered Species Act and Marine Mammal Protection Act and Canada's Species at Risk Act. There are about 400 individuals in existence in the western North Atlantic Ocean—they migrate between feeding grounds in the Labrador Sea and their winter calving areas off Georgia and Florida, an ocean area with heavy shipping traffic. In the eastern North Atlantic, on the other hand—with a total population reaching into the low teens at best—scientists believe that they may already be functionally extinct. Vessel strikes and entanglement in fixed fishing gear, which together account for nearly half of all North Atlantic right whale mortality since 1970, are their two greatest threats to recovery.North Pacific right whale
The North Pacific right whale (Eubalaena japonica) is a very large, thickset baleen whale species that is extremely rare and endangered.
The Northeast Pacific population, which summers in the southeastern Bering Sea and Gulf of Alaska, may have no more than 40 animals. A western population that summers near the Commander Islands, the coast of Kamchatka, along the Kuril Islands and in the Sea of Okhotsk is thought to number in the low hundreds. Before commercial whaling in the North Pacific (i.e. pre-1835) there were probably over 20,000 right whales in the region. The taking of right whales in commercial whaling has been prohibited by one or more international treaties since 1935. Nevertheless, between 1962 and 1968, illegal Soviet whaling killed at least 529 right whales in the Bering Sea and Gulf of Alaska as well as at least 132 right whales in the Sea Okhotsk. plus an additional 104 North Pacific right whales from unspecified areas.The International Union for Conservation of Nature categorizes the species as "Endangered", and categorizes the Northeast Pacific population as "Critically Endangered". The Center for Biological Diversity argues that the North Pacific right whale is the most endangered whale on Earth.Northern right whale dolphin
The northern right whale dolphin (Lissodelphis borealis) is a small, slender and finless species of marine mammal found in the North Pacific Ocean. It travels in groups of up to 2000, often with other cetaceans, in deep waters of the North Pacific. The dolphin is one of two species of right whale dolphin, the other being found in cooler oceans of the Southern Hemisphere.Pygmy right whale
The pygmy right whale (Caperea marginata) is a member of the cetotheres, a family of baleen whales, which until 2012 were thought to be extinct; previously C. marginata was considered the sole member of the family Neobalaenidae. First described by John Edward Gray in 1846, it is the smallest of the baleen whales, ranging between 6 and 6.5 metres (20 and 21 ft) in length and 3,000 and 3,500 kilograms (6,610 and 7,720 lb) in mass. Despite its name, the pygmy right whale may have more in common with the gray whale and rorquals than the bowhead and right whales.The pygmy right whale is found in the Southern Ocean in the lower reaches of the Southern Hemisphere, and feeds on copepods and euphausiids. Little is known about its population or social habits. Unlike most other baleen whales, it has rarely been subject to exploitation.Right whale dolphin
Right whale dolphins are cetaceans belonging to the genus Lissodelphis. It contains the northern right whale dolphin (Lissodelphis borealis) and the southern right whale dolphin (Lissodelphis peronii). These cetaceans are predominantly black, white beneath, and some of the few without a dorsal fin or ridge. They are smaller members of the delphinid family, oceanic dolphins, and very slender. Despite scientists being long acquainted with the species (the Northern species was identified by Peale in 1848 and the Southern by La Cépède in 1804), little is known about them in terms of life history and behaviour.Shepherd's beaked whale
Shepherd's beaked whale (Tasmacetus shepherdi), also commonly called Tasman's beaked whale or simply the Tasman whale, is a cetacean of the family Ziphiidae. The whale has not been studied extensively. Only four confirmed at sea sightings have been made and 42 strandings recorded (as of 2006). It was first known to science in 1937, being named by W. R. B. Oliver after George Shepherd, curator of the Wanganui Museum, who collected the type specimen near Ohawe on the south Taranaki coast of New Zealand's North Island, in 1933.Southern right whale
The southern right whale (Eubalaena australis) is a baleen whale, one of three species classified as right whales belonging to the genus Eubalaena.
Approximately 10,000 southern right whales are spread throughout the southern part of the Southern Hemisphere.Southern right whale dolphin
The southern right whale dolphin (Lissodelphis peronii) is a small and slender species of mammal found in cool waters of the Southern Hemisphere. The dolphin is one of two species of right whale dolphin; Lissodelphis, the other, the northern right whale dolphin, is found in deep oceans of the Northern Hemisphere.Stenella
Stenella is a genus of aquatic mammals in Delphinidae, the family informally known as the oceanic dolphins.Currently, five species are recognised in this genus:
Pantropical spotted dolphin, S. attenuata
Atlantic spotted dolphin, S. frontalis
Spinner dolphin, S. longirostris
Clymene dolphin, S. clymene
Striped dolphin, S. coeruleoalbaThe common name for species in this genus is the "spotted dolphins" or the "bridled dolphins". They are found in temperate and tropical seas all around the world. Individuals of several species begin their lives spotless and become steadily more covered in darker spots as they get older.The genus name comes from the Greek stenos meaning narrow. It was coined by John Gray in 1866 when he intended it as a subgenus of Steno. Modern taxonomists recognise two genera.The clymene dolphin (S. clymene) is the only confirmed case of hybrid speciation in marine mammals, descending from the spinner dolphin (S. longirostris) and the striped dolphin (S. coeruleoalba).
Extant Cetacea species