List of cetacean species

Cetaceans
Temporal range: Early EocenePresent
Bottlenose dolphin breaching
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Class: Mammalia
Order: Cetartiodactyla[lower-alpha 1]
Suborder: Whippomorpha
Infraorder: Cetacea
Subgroups
IUCN Red List categories
Conservation status
EW Extinct in the wild
CR Critically endangered
EN Endangered
VU Vulnerable
NT Near threatened
CD Conservation dependent
LC Least Concern
Other category
DD Data deficient
NE Not evaluated

Cetaceanswhales, dolphins and porpoises – are placental marine mammals. All modern members of the infraorder are fully aquatic and live in the open ocean (except a few species of dolphin which inhabit rivers and estuaries). Cetaceans mate, give birth, suckle their young, and feed exclusively underwater. They range in size from the 1.4-metre (4.6 ft) and 54-kilogram (119 lb) vaquita to the 29.9-metre (98 ft) and 190-metric-ton (210-short-ton) blue whale, which is also the largest creature that has ever existed. Fourteen families, 39 genera, and 88 species of cetaceans are recognised by the International Union for Conservation of Nature (IUCN). Of the 88 species, the IUCN classifies three as Critically Endangered, seven as Endangered, six as Vulnerable, five as Near Threatened, twenty two as Least Concern, and 45 as Data Deficient.[7]

Cetaceans are characterized by a fusiform body, paddle-shaped front limbs and vestigial hind limbs. Their tails have been flattened into flukes to aid propulsion. They have lungs, and must surface regularly to breathe air through blowholes (modified nostrils) situated on the top of the cranium. The cetaceans are included in the order Cetartiodactyla[lower-alpha 2] with the Artiodactyla (the even-toed ungulates). Previously, they were placed within their own order, Cetacea, now an infraorder. They are divided into two subgroups, the Odontoceti (the toothed whales, including dolphins and porpoises) and the Mysticeti (the baleen whales), formerly suborders but now considered parvorders or unranked taxa. There are 89 living species of cetaceans (including the functionally extinct Chinese river dolphin).[10] In addition, numerous species of extinct cetaceans have been documented, but they are not listed here. This list contains only the known, extant cetacean species including several recently defined species.

Cetaceans are widespread, but some, as with the mysticetes, specialise in certain environments. Most mysticetes prefer the colder waters of the Northern and Southern Hemispheres, and migrate to the equator to give birth. Odontocetes feed largely on fish and squid, but a few, like the killer whale, feed on mammals, such as pinnipeds. Gray whales are specialized for feeding on bottom-dwelling mollusks. Males typically mate with multiple females every year, but females only mate every two to three years. Calves are typically born in the spring and summer months and females bear all the responsibility for raising them. Mothers of some species fast and nurse their young for a relatively long period of time. Some whales produce a variety of vocalizations, notably the songs of the humpback whale. Many species, mainly dolphins, are highly sociable, with some pods reaching over a thousand individuals.[11]

Once relentlessly hunted for their products, whales are now protected by international law. Some species are attributed with high levels of intelligence. At the 2012 meeting of the American Association for the Advancement of Science, support was reiterated for a cetacean bill of rights, listing cetaceans as non-human persons.[12] The North Atlantic right whales nearly became extinct in the twentieth century, with a population low of 450, and are considered functionally extinct by cetologists.[13] The baiji is also considered functionally extinct by the IUCN with, the last sighting in 2004.[10] Besides whaling, they also face threats from bycatch and marine pollution. The meat, blubber and baleen of whales have traditionally been used by indigenous peoples of the Arctic. Whales occasionally feature in literature and film, as in the great white whale of Herman Melville's Moby Dick. Small cetaceans, mainly dolphins, are kept in captivity and trained to perform tricks, but breeding success has been poor. Whale watching has become a form of tourism around the world.

Conventions

Conservation status

Conservation status codes listed follow the IUCN red list of threatened species (v. 2014.3; data current at 20 January 2015).[14]

Global population estimates

Where available, the global population estimate has been listed. When not cited or footnoted differently, these are from the IUCN red list of threatened species (v. 2014.3; data current at 20 January 2015).[14]

Mysticeti: baleen whales

The baleen whales, also called whalebone whales or great whales, form the Mysticeti. Baleen whales are characterized by having baleen plates for filter feeding and two blowholes. During the embryonic phase, Mysticetes do have teeth but they are reabsorbed before birth [15]

Family Balaenidae: right whales

The family Balaenidae contains two genera and four species. All the Balaenidae whales have no ventral grooves; a distinctive head shape with a strongly arched, narrow rostrum, bowed lower jaw; lower lips that enfold the sides and front of the rostrum; long, narrow, elastic baleen plates (up to 9 times longer than wide) with fine baleen fringes; and fused cervical vertebrae rendering the head immobile.[16]

Genus Balaena Linnaeus, 1758 – one species
Common nameScientific nameIUCN Red List StatusGlobal Population EstimateRangeSizePicture
Bowhead whale Balaena mysticetus
Linnaeus, 1758
LC IUCN 12,682–39,950
60 tonnes
Genus Eubalaena Gray, 1864 – 3 species
Common nameScientific nameIUCN Red List StatusGlobal Population EstimateRangeSizePicture
North Atlantic right whale Eubalaena glacialis
Müller, 1776
EN IUCN 300-350
40–80 tonnes
North Pacific right whale Eubalaena japonica
Lacépède, 1818
EN IUCN 404-2,108[17]
60–80 tonnes
Southern right whale Eubalaena australis
Desmoulins, 1822
LC IUCN 7,500
40–80 tonnes

Family Balaenopteridae: rorquals

Rorquals are the largest group of baleen whales, with 9 species in two genera. They include the largest animal that has ever lived, the blue whale, which can reach 190 tonnes, the fin whale can easily reach 50 tonnes, and even the smallest of the group, the northern minke whale, reaches 9 tonnes. They take their name from a Norwegian word meaning "furrow whale": 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, which has shorter grooves). These are understood to allow the mouth to expand immensely when feeding.[18] All rorquals have ventral grooves, and are the only cetaceans to have them. Additionally, they all have dorsal fins, broad, gently curving rostra and short baleen plates.[16]

Subfamily Balaenopterinae – one genus, eight species
Genus Balaenoptera – eight species
Common nameScientific nameStatusPopulationDistributionSizePicture
Blue whale Balaenoptera musculus
Linnaeus, 1758
EN IUCN 10,000-25,000
50-150 tonnes
Bryde's whale Balaenoptera brydei
Olsen, 1913
DD IUCN 90,000–100,000
14–30 tonnes
Common minke whale Balaenoptera acutorostrata
Lacépède, 1804
LC IUCN Unknown
6-11 tonnes
Eden's whale Balaenoptera edeni
Anderson, 1879
DD IUCN Unknown Unknown
Fin whale Balaenoptera physalus
Linnaeus, 1758
EN IUCN 100,000
30–80 tonnes
Omura's whale Balaenoptera omurai
Wada et al., 2003
DD IUCN Unknown Unknown Unknown
Sei whale Balaenoptera borealis
Lesson, 1828
EN IUCN 57,000
20–25 tonnes
Antarctic minke whale Balaenoptera bonaerensis
Burmeister, 1867
DD IUCN 515,000
6-10 tonnes
Subfamily Megapterinae – 1 genus, 1 species
Genus Megaptera Gray, 1846 – 1 species
Common nameScientific nameStatusPopulationDistributionSizePicture
Humpback whale Megaptera novaeangliae
Borowski, 1781
LC IUCN 80,000
25–30 tonnes

Family Cetotheriidae: pygmy right whale

The pygmy right whale shares several characteristics with the right whales, although having dorsal fins separates them from right whales, and they have a very distinctive jaw configuration. Pygmy right whales' heads are no more than one-fourth the size of their bodies, whereas the right whales' heads are about one-third the size of their bodies.[16]

Genus Caperea Gray, 1864 – 1 species
Common nameScientific nameStatusPopulationDistributionSizePicture
Pygmy right whale Caperea marginata
Gray, 1846
DD IUCN Unknown
3-3.5 tonnes

Family Eschrichtiidae: gray whale

The gray whale has been placed in a family of its own as it is sufficiently different from the right whales and the rorquals. The gray whale is the only benthic feeding baleen whale, filtering small organisms from the mud of shallow seas. They also have a gestation period of over a year, which is unusual for baleen whales.[16]

Genus Eschrichtius – 1 species
Common nameScientific nameStatusPopulationDistributionSizePicture
Gray whale Eschrichtius robustus
Lilljeborg, 1861
LC IUCN 26,000
15–40 tonnes

Odontoceti: toothed whales

The toothed whales (systematic name Odontoceti) form a parvorder of the cetaceans. As the name suggests, the parvorder is characterized by having teeth (rather than baleen). Toothed whales are active hunters, feeding on fish, squid, and in some cases other marine mammals.

Family Delphinidae: oceanic dolphins

Oceanic dolphins are the members of the cetacean family Delphinidae. These aquatic mammals are related to whales and porpoises. As the name implies, these dolphins tend to be found in the open seas, unlike the river dolphins, although a few species such as the Irrawaddy dolphin are coastal or riverine. Six of the larger species in the Delphinidae, the killer whale (orca) and its relatives, are commonly called whales, rather than dolphins. They are also sometimes collectively known as "blackfish".

The Delphinidae are characterized by having distinct beaks (unlike the Phocoenidae), two or more fused cervical vertebrae and 20 or more pairs of teeth in their upper jaws. None is more than 4 m long.[16]

Genus Cephalorhynchus Gray, 1846 – four species
Common nameScientific nameStatusPopulationDistributionSizePicture
Chilean dolphin Cephalorhynchus eutropia
Gray, 1846
NT IUCN Unknown
60 kg
Commerson's dolphin Cephalorhynchus commersonii
Lacépède, 1804
DD IUCN 3,400
35–60 kilograms
Heaviside's dolphin Cephalorhynchus heavisidii
Gray, 1828
DD IUCN Unknown
40–75 kg
Hector's dolphin Cephalorhynchus hectori
Van Beneden, 1881
EN IUCN (subspecies Maui's dolphin CR IUCN) 2,000–2,500 (subspecies Maui's 55 in 2012)
35–60 kg
Genus Delphinus – three species
Common nameScientific nameStatusPopulationDistributionSizePicture
Arabian common dolphin[lower-alpha 3] Delphinus tropicalis
van Bree, 1971
NE Unknown
65–105 kg
Long-beaked common dolphin Delphinus capensis
Gray, 1828
DD IUCN Unknown [lower-alpha 4]
80–150 kg
Short-beaked common dolphin Delphinus delphis
Linnaeus, 1758
LC IUCN
70–110 kg
Genus Feresa – one species
Common nameScientific nameStatusPopulationDistributionSizePicture
Pygmy killer whale Feresa attenuata
Gray, 1875
DD IUCN Unknown [lower-alpha 5]
160–350 kg
Genus Globicephala – two species
Common nameScientific nameStatusPopulationDistributionSizePicture
Long-finned pilot whale Globicephala melas
Traill, 1809
DD IUCN Unknown [lower-alpha 6]
3-3.5 tonnes
Short-finned pilot whale Globicephala macrorhynchus
Gray, 1846
DD IUCN Unknown [lower-alpha 7]
1–3 tonnes
Genus Grampus – one species
Common nameScientific nameStatusPopulationDistributionSizePicture
Risso's dolphin Grampus griseus
G. Cuvier, 1812
LC IUCN Unknown [lower-alpha 8]
300 kg
Genus Lagenodelphis – one species
Common nameScientific nameStatusPopulationDistributionSizePicture
Fraser's dolphin Lagenodelphis hosei
Fraser, 1956
LC IUCN Unknown
209 kg
Genus Lagenorhynchus Gray, 1846 – six species
Common nameScientific nameStatusPopulationDistributionSizePicture
Atlantic white-sided dolphin Lagenorhynchus acutus
Gray, 1828
LC IUCN 200,000 – 300,000
235 kg
Dusky dolphin Lagenorhynchus obscurus
Gray, 1828
DD IUCN Unknown
100 kg
Hourglass dolphin Lagenorhynchus cruciger
Quoy & Gaimard, 1824
LC IUCN 140,000
90–120 kg
Pacific white-sided dolphin Lagenorhynchus obliquidens
Gill, 1865
LC IUCN 1,000,000
85–150 kg
Peale's dolphin Lagenorhynchus australis
Peale, 1848
DD IUCN Unknown [lower-alpha 9]
115 kg
White-beaked dolphin Lagenorhynchus albirostris
Gray, 1846
LC IUCN 100,000 [lower-alpha 10]
180 kg
Genus Lissodelphis – two species
Common nameScientific nameStatusPopulationDistributionSizePicture
Northern right whale dolphin Lissodelphis borealis
Peale, 1848
LC IUCN 400,000 [lower-alpha 11]
115 kg
Southern right whale dolphin Lissodelphis peronii
Lacépède, 1804
DD IUCN Unknown [lower-alpha 12]
60–100 kg
Genus Orcaella Gray, 1866 – two species
Common nameScientific nameStatusPopulationDistributionSizePicture
Australian snubfin dolphin Orcaella heinsohni
Beasley, Robertson & Arnold, 2005
NT IUCN Unknown
130–145 kg
Irrawaddy dolphin Orcaella brevirostris
Gray, 1866
VU IUCN Unknown
130 kg
Genus Orcinus – one species
Common nameScientific nameStatusPopulationDistributionSizePicture
Killer whale Orcinus orca
Linnaeus, 1758
DD IUCN 100,000 [lower-alpha 13]
4.5 tonnes
Genus Peponocephala – one species
Common nameScientific nameStatusPopulationDistributionSizePicture
Melon-headed whale Peponocephala electra
Gray, 1846
LC IUCN Unknown [lower-alpha 14]
225 kg
Genus Pseudorca – one species
Common nameScientific nameStatusPopulationDistributionSizePicture
False killer whale Pseudorca crassidens
Owen, 1846
DD IUCN Unknown [lower-alpha 15]
1.5-2 tonnes
Genus Sousa – four species
Common nameScientific nameStatusPopulationDistributionSizePicture
Atlantic humpback dolphin Sousa teuszi
Kükenthal, 1892
DD IUCN Unknown
100–150 kg
(cetacean needed)
Australian humpback dolphin Sousa sahulensis
Jefferson & Rosenbaum, 2014
NE Unknown
Indian humpback dolphin Sousa plumbea
Cuvier, 1829
DD Unknown
Pacific humpback dolphin Sousa chinensis
Osbeck, 1765
DD IUCN Unknown
250–280 kg
Genus Sotalia – two species
Common nameScientific nameStatusPopulationDistributionSizePicture
Guiana dolphin Sotalia guianensis
Bénéden, 1864
DD IUCN Unknown
Solid color

35–45 kg
Tucuxi Sotalia fluviatilis
Gervais & Deville, 1853
DD IUCN Unknown
Hashed color

35–45 kg
Genus Stenella Gray, 1866 – five species
Common nameScientific nameStatusPopulationDistributionSizePicture
Atlantic spotted dolphin Stenella frontalis
Cuvier, 1829
DD IUCN 100,000
100 kg
Clymene dolphin Stenella clymene
Gray, 1846
DD IUCN Unknown
75–80 kg
Pantropical spotted dolphin Stenella attenuata
Gray, 1846
CD IUCN 3,000,000
100 kg
Spinner dolphin Stenella longirostris
Gray, 1828
DD IUCN Unknown
90 kg
Striped dolphin Stenella coeruleoalba
Meyen, 1833
CD IUCN 2,000,000
100 kg
Genus Steno – one species
Common nameScientific nameStatusPopulationDistributionSizePicture
Rough-toothed dolphin Steno bredanensis
Lesson, 1828
LC IUCN 150,000
100–135 kg
Genus Tursiops – three species
Common nameScientific nameStatusPopulationDistributionSizePicture
Burrunan dolphin[lower-alpha 16] Tursiops australis NE Unknown
Common bottlenose dolphin Tursiops truncatus
Montagu, 1821
LC IUCN Unknown
150–650 kg
Indo-Pacific bottlenose dolphin Tursiops aduncus
Ehrenberg, 1833
DD IUCN Unknown
230 kg

Family Monodontidae: narwhal and beluga

The cetacean family Monodontidae comprises two unusual whale species, the narwhal, in which the male has a long tusk, and the white beluga.

The Monodontidae lack dorsal fins, which have been replaced by tough, fibrous ridges just behind the midpoints of their bodies and are probably an adaptation to swimming under ice, as both do in their Arctic habitat. The flippers are small, rounded and tend to curl up at the ends in adulthood. All, or almost all, the cervical vertebrae are unfused, allowing their heads to be turned independently of their bodies. None has any throat grooves.[16]

Genus Delphinapterus – one species
Common nameScientific nameStatusPopulationDistributionSizePicture
Beluga Delphinapterus leucas
Pallas, 1776
NT IUCN 100,000 [lower-alpha 17]
1.5 tonnes
Genus Monodon – one species
Common nameScientific nameStatusPopulationDistributionSizePicture
Narwhal(e) Monodon monoceros
Linnaeus, 1758
NT IUCN 25,000 [lower-alpha 18]
900-1,500 kilograms

Family Kogiidae: dwarf and pygmy sperm whales

The dwarf and pygmy sperm whales resemble sperm whales, but are far smaller. They are dark gray, dorsally, while ventrally they are lighter. They have blunt, squarish heads with narrow, underslung jaws; the flippers are set far forward, close to the head and their dorsal fins are set far back down the body.

Genus Kogia – two species
Common nameScientific nameStatusPopulationDistributionSizePicture
Dwarf sperm whale Kogia sima
Owen, 1866
DD IUCN Unknown [lower-alpha 19]
250 kg
Pygmy sperm whale Kogia breviceps
Blainville, 1838
DD IUCN Unknown [lower-alpha 20]
400 kg

Family Phocoenidae: porpoises

Porpoises are small cetaceans of the family Phocoenidae. They are distinct from dolphins, although the word "porpoise" has been used to refer to any small dolphin, especially by sailors and fishermen. The most obvious visible difference between the two groups is porpoises have spatulate (flattened) teeth distinct from the conical teeth of dolphins. In addition, porpoises are relatively r-selected compared with dolphins: that is, they rear more young more quickly than dolphins. All seven species have small flippers, notched tail flukes, and no beaks. All carry at least 11 pairs of small teeth in their upper and lower jaws.

Porpoises, divided into seven species, live in all oceans, mostly near the shore. Probably best known is the harbour porpoise, which can be found across the Northern Hemisphere.

Genus Neophocaena – two species
Common nameScientific nameStatusPopulationDistributionSizePicture
Indo-pacific finless porpoise Neophocaena phocaenoides
Cuvier, 1829
VU IUCN[lower-alpha 21] Unknown [lower-alpha 22]
30–45 kg
Narrow-ridged finless porpoise Neophocaena asiaeorientalis
Cuvier, 1829
CR IUCN[lower-alpha 23] 1,000
30–45 kg
Genus Phocoena – four species
Common nameScientific nameStatusPopulationDistributionSizePicture
Burmeister's porpoise Phocoena spinipinnis
Burmeister, 1865
DD IUCN Unknown [lower-alpha 24]
50–75 kg
(cetacean needed)
Harbour porpoise Phocoena phocoena
Linnaeus, 1758
LC IUCN 700,000 [20]
75 kg
Spectacled porpoise Phocoena dioptrica
Lahille, 1912
DD IUCN Unknown [lower-alpha 25]
60–84 kg
(cetacean needed)
Vaquita Phocoena sinus
Norris & McFarland, 1958
CR IUCN 500 [lower-alpha 26]
50 kg
Genus Phocoenoides – 1 species
Common nameScientific nameStatusPopulationDistributionSizePicture
Dall's porpoise Phocoenoides dalli
True, 1885
LC IUCN 1,100,000 [lower-alpha 27]
130–200 kg

Family Physeteridae: sperm whale

The sperm whale characteristically has a large, squarish head one-third the length of its body; the blowhole is slightly to the left hand side; the skin is usually wrinkled; and it has no teeth on the upper jaw.

Genus Physeter – one species
Common nameScientific nameStatusPopulationDistributionSizePicture
Sperm whale Physeter macrocephalus
Linnaeus, 1758
VU IUCN 200,000–2,000,000 [lower-alpha 28]
25–50 tonnes

Family Ziphiidae: beaked whales

A beaked whale is any of at least 22 species of small whale in the family Ziphiidae. They are one of the least-known families of large mammals: several species have only been described in the last two decades, and it is entirely possible that more remain as yet undiscovered. Six genera have been identified.

They possess a unique feeding mechanism known as suction feeding. Instead of catching their prey with teeth, it is sucked into their oral cavity. Their tongue can move very freely, and when suddenly retracted at the same time as the gular floor is distended, the pressure immediately drops within their mouth and the prey is sucked in with the water. The family members are characterized by having a lower jaw that extends at least to the tip of the upper jaw, a shallow or non-existent notch between the tail flukes, a dorsal fin set well back on the body, three of four fused cervical vertebrae, extensive skull asymmetry and two conspicuous throat grooves forming a 'V' pattern.[16]

Genus Berardius – two species
Common nameScientific nameStatusPopulationDistributionSizePicture
Arnoux's beaked whale Berardius arnuxii
Duvernoy, 1851
DD IUCN Unknown [lower-alpha 29]
8 tonnes
Baird's beaked whale Berardius bairdii
Stejneger, 1883
DD IUCN Unknown [lower-alpha 30]
12 tonnes
(cetacean needed)
Genus Tasmacetus – one species
Common nameScientific nameStatusPopulationDistributionSizePicture
Shepherd's beaked whale Tasmacetus shepherdi
Oliver, 1937
DD IUCN Unknown [lower-alpha 31]
2-2.5 tonnes
(cetacean needed)
Genus Ziphius – one species
Common nameScientific nameStatusPopulationDistributionSizePicture
Cuvier's beaked whale Ziphius cavirostris
G. Cuvier, 1823
LC Unknown [lower-alpha 32]
2–3 tonnes
Subfamily Hyperoodontinae – three genera, 17 species
Genus Hyperoodon – two species
Common nameScientific nameStatusPopulationDistributionSizePicture
Northern bottlenose whale Hyperoodon ampullatus
Forster, 1770
DD IUCN 10,000 [lower-alpha 33]
7 tonnes
Southern bottlenose whale Hyperoodon planifrons
Flower, 1882
LC IUCN 500,000
6 tonnes
(cetacean needed)
Genus Indopacetus – one species
Common nameScientific nameStatusPopulationDistributionSizePicture
Tropical bottlenose whale Indopacetus pacificus
Longman, 1926
DD IUCN Unknown [lower-alpha 34]
3,5-4 tonnes
(cetacean needed)
Genus Mesoplodon Gervais, 1850 – 15 species
Common nameScientific nameStatusPopulationDistributionSizePicture
Andrews' beaked whale Mesoplodon bowdoini
Andrews, 1908
DD IUCN Unknown
1 tonne
Blainville's beaked whale Mesoplodon densirostris
Blainville, 1817
DD IUCN Unknown
Deraniyagala's beaked whale Mesoplodon hotaula
P. E. P. Deraniyagala, 1963
NE Unknown (cetacean needed)
Gervais' beaked whale Mesoplodon europaeus
Gervais, 1855
DD IUCN Unknown
1.2 tonnes
(cetacean needed)
Ginkgo-toothed beaked whale Mesoplodon ginkgodens
Nishiwaki & Kamiya, 1958
DD IUCN Unknown
1.5 tonnes
Gray's beaked whale Mesoplodon grayi
von Haast, 1876
DD IUCN Unknown
1.5 tonnes
Hector's beaked whale Mesoplodon hectori
Gray, 1871
DD IUCN Unknown
1 tonne
Hubbs' beaked whale Mesoplodon carlhubbsi
Moore, 1963
DD IUCN Unknown
1.4 tonnes
(cetacean needed)
Perrin's beaked whale Mesoplodon perrini
Dalebout, Mead, Baker, Baker, & van Helding, 2002
DD IUCN Unknown
1.3–1.5 tonnes
(cetacean needed)
Pygmy beaked whale Mesoplodon peruvianus
Reyes, Mead, and Van Waerebeek, 1991
DD IUCN Unknown
800 kg
(cetacean needed)
Sowerby's beaked whale Mesoplodon bidens
Sowerby, 1804
VU IUCN Unknown
1-1.3 tonnes
Spade-toothed whale Mesoplodon traversii, syn. Mesoplodon bahamondi
Gray, 1874
DD IUCN Unknown
1.2 tonnes
(cetacean needed)
Stejneger's beaked whale Mesoplodon stejnegeri
True, 1885
DD IUCN Unknown
1.5 tonnes
Strap-toothed whale Mesoplodon layardii
Gray, 1865
DD IUCN Unknown
2 tonnes
True's beaked whale Mesoplodon mirus
True, 1913
DD IUCN Unknown
1.4 tonnes

Superfamily Platanistoidea: river dolphins

River dolphins are five species of dolphins which reside in freshwater rivers and estuaries. They are classed in the cetacean superfamily Platanistoidea. Four species live in fresh water rivers. The fifth species, the La Plata dolphin, lives in saltwater estuaries and the ocean. However, it is scientifically classed in the river dolphin family rather than the oceanic dolphin family. All species have adaptations to facilitate fish catching: a long, forceps-like beak with numerous small teeth in both jaws, broad flippers to allow tight turns, small eyes, and unfused neck vertebrae to allow the head to move in relation to the body.

Family Iniidae: river dolphins

This family contains one genus of two species, although the Amazon river dolphin (I. geoffrensis) has been divided into three subspecies:

Genus Inia – two species
Common nameScientific nameStatusPopulationDistributionSizePicture
Amazon river dolphin Inia geoffrensis
Blainville, 1817
DD IUCN Unknown
150 kg
Araguaian river dolphin Inia araguaiaensis
Hrbek, Da Silva, Dutra, Farias, 2014
NE Unknown
Araguaian river dolphin in blue

150 kg

Family Lipotidae: baiji

The family Lipotidae is another monotypic taxon, containing only the baiji. Fossil records suggest the dolphin first appeared 25 million years ago and migrated from the Pacific Ocean to the Yangtze River 20 million years ago.[21] The species was declared functionally extinct in 2006 after an expedition to record population numbers found no specimens.

Genus Lipotes – one species
Common nameScientific nameStatusPopulationDistributionSizePicture
Baiji Lipotes vexillifer
Miller, 1918
CR IUCN 0-13 [lower-alpha 35]
130 kg

Family Platanistidae: South Asian river dolphin

The Platanistidae were originally thought to hold only one species (the South Asian river dolphin), but based on differences in skull structure, vertebrae and lipid composition, scientists declared the two populations as separate species in the early 1970s.[22] In 1998, the results of these studies were questioned and the classification reverted to the pre-1970 consensus. Thus, at present, two subspecies are recognized in the genus Platanista, P. gangetica minor (the Indus river dolphin) and P. g. gangetica (the Ganges river dolphin).[23]

Genus Platanista – one species
Common nameScientific nameStatusPopulationDistributionSizePicture
South Asian river dolphin Platanista gangetica
Roxburgh, 1801
EN IUCN 1,100 [lower-alpha 36]
200 kg

Family Pontoporiidae: La Plata dolphin

The La Plata dolphin is the only species of the family Pontoporiidae and genus Pontoporia.

Genus Pontoporia – one species
Common nameScientific nameStatusPopulationDistributionSizePicture
La Plata dolphin Pontoporia blainvillei
Gervais & d'Orbigny, 1844
VU IUCN 4,000–4,500
50 kg

See also

Footnotes

  1. The use of order Cetartiodactyla instead of Cetacea, with the latter demoted to an infraorder with parvorders Odontoceti and Mysticeti, is favored by most evolutionary mammalogists working with molecular data [1][2][3][4] and is supported the IUCN Cetacean Specialist Group[5] and by Taxonomy Committee [6] of the Society for Marine Mammalogy, the largest international association of marine mammal scientists in the world. See Cetartiodactyla and Marine mammal articles for further discussion.
  2. Based on molecular and morphological research, the cetaceans genetically and morphologically fall firmly within the Artiodactyla (even-toed ungulates).[8][9] The term Cetartiodactyla reflects the idea that whales evolved within the ungulates. The term was coined by merging the name for the two orders, Cetacea and Artiodactyla, into a single word. The closest living relatives of whales and dolphins are thought to be the hippopotamuses. Use of Order Cetartiodactyla, demoting Cetacea to an infraorder with parvorders Odontoceti and Mysticeti, is favored by most evolutionary mammalogists working with molecular data[1][2][3][4] and is supported the IUCN Cetacean Specialist Group[5] and by Taxonomy Committee[6] of the Society for Marine Mammalogy, the largest international association of marine mammal scientists in the world. Some others, including many marine mammalogists and paleontologists, favor retention of Order Cetacea with two suborders in the interest of taxonomic stability. See Cetartiodactyla and Marine mammal articles for further discussion.
  3. As of May 2016, the Arabian common dolphin is considered a subspecies of the common dolphin by the Society for Marine Mammalogy[19]
  4. The total population is unknown but numbers in the hundreds of thousands
  5. The only population estimate is of 38,900 individuals in the eastern tropical Pacific Ocean
  6. Total population is not known. There are estimated to be in excess of 200,000 in the Southern Ocean. The North Atlantic population is not known
  7. Total population not known. There are 150,000 individuals in the eastern tropical Pacific Ocean. There are estimated to be more than 30,000 animals in the western Pacific, off the coast of Japan
  8. The population around the continental shelf of the United States has been recorded to be in excess of 60,000. In the Pacific, a census recorded 175,000 individuals in eastern tropical waters and 85,000 in the west. No global estimate of population exists
  9. Total population unknown but thought to be locally common – it is the most common dolphin found around the Falkland Islands
  10. Estimates of various stocks throughout the North Atlantic give an overall value into the high tens or low hundreds of thousands
  11. Varying population estimates for areas around California and the North Pacific give a total of up to 400,000
  12. Surveys suggest this is the most common dolphin off of Chilean waters
  13. Local estimates include 70–80,000 in the Antarctic, 8,000 in the tropical Pacific (although tropical waters are not the orca's preferred environment, the sheer size of this area — 19 million square kilometres — means there are thousands of orcas), up to 2,000 off Japan, 1,500 off the cooler northeast Pacific and 1,500 off Norway
  14. Estimates for eastern tropical Pacific are 45,000 and another recent survey estimates population to be 1,200 for the eastern Sulu Sea, no global estimate is known
  15. The total population is unknown. The eastern Pacific was estimated to have in excess of 40,000 individuals and is probably the home of the largest grouping
  16. As of May 2016, the Society for Marine Mammalogy does not consider the Burrunan dolphin a distinct species due to problematic methodology in the study proposing its classification. The organization recommends further study to determine its validity.[19]
  17. There are estimated to be 40,000 individuals in the Beaufort Sea, 25,000 in Hudson Bay, 18,000 in the Bering Sea and 28,000 in the Canadian High Arctic. The population in the St. Lawrence estuary is estimated to be around 1000
  18. Aerial surveys suggest a population of around 20,000 individuals. When submerged animals are also taken into account, the true figure may be in excess of 25,000
  19. No global population estimates have been made. One survey estimated a population of about 11,000 in the eastern Pacific
  20. No global population estimates have been made. One survey estimated a population of about 11,000 in the eastern Pacific
  21. There is not enough data to place finless porpoises on the endangered species list
  22. There are no good estimates of the animals' abundance. However a comparison of two surveys, one from the late 1970s and the other from 1999/2000 shows a decline in population and distribution
  23. In China, they are endangered. Their propensity for staying close to shore places them in great danger from fishing
  24. There are no quantitative data on abundance
  25. Nothing is known of the abundance of this porpoise. It was the most commonly encountered species during preliminary beach surveys undertaken on Tierra del Fuego
  26. Only few serious attempts have been made to estimate the total size of the vaquita population. Varying numbers have been obtained although an average of about 500 is usually found
  27. The most recent estimate for the North Pacific and Bering Sea is 1,186,000
  28. The total number of sperm whales throughout the world is unknown. Crude estimates, obtained by surveying small areas and extrapolating the result to all the world's oceans, range from 200,000 to 2,000,000 individuals
  29. Arnoux's beaked whales seem to be relatively abundant in Cook Strait during summer
  30. Virtually nothing is known about the abundance of Baird's beaked whales, except they are not rare as was formerly thought
  31. Nothing is known about the relative abundance of this species or its population composition
  32. Because of the difficulty of identifying the species the total global population is unknown
  33. Total population is unknown but likely to be of the order of 10,000
  34. A 2002 survey estimates there are 766 animals around Hawaii. No other population estimates exist for other locales
  35. A survey from November–December 2006 failed to find any individuals. Another survey, from 1997, counted only 13 individuals. In 1986, surveys estimated the number to be at about 300
  36. Estimates give values of 1,100 Indus river dolphins and maybe as few as 20 Ganges river dolphins

References

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  2. 1 2 Price, SA.; Bininda-Emonds, OR.; Gittleman, JL. (2005). "A complete phylogeny of the whales, dolphins and even-toed hoofed mammals – Cetartiodactyla". Biol Rev Camb Philos Soc. 80 (3): 445–473. PMID 16094808. doi:10.1017/s1464793105006743.
  3. 1 2 Montgelard, C.; Catzeflis, FM.; Douzery, E. (1997). "Phylogenetic relationships of artiodactyls and cetaceans as deduced from the comparison of cytochrome b and 12S RNA mitochondrial sequences". Molecular Biology and Evolution. 14 (5): 550–559. PMID 9159933. doi:10.1093/oxfordjournals.molbev.a025792.
  4. 1 2 Spaulding, M.; O'Leary, MA.; Gatesy, J. (2009). "Relationships of Cetacea -Artiodactyla- Among Mammals: Increased Taxon Sampling Alters Interpretations of Key Fossils and Character Evolution". PLoS ONE. 4 (9): e7062. Bibcode:2009PLoSO...4.7062S. PMC 2740860Freely accessible. PMID 19774069. doi:10.1371/journal.pone.0007062.
  5. 1 2 "Cetacean Species and Taxonomy". IUCN-SSC: Cetacean Specialist Group. Retrieved December 14, 2015.
  6. 1 2 "List of Marine Mammal Species and Subspecies". Society for Marine Mammalogy. Archived from the original on January 6, 2015. Retrieved December 15, 2015.
  7. IUCN. "Status of the World's Cetaceans". IUCN–SSC: Cetacean Specialist Group. Retrieved December 14, 2015.
  8. Geisler, Jonathan H.; Uden, Mark D. (2005). "Phylogenetic Relationships of Extinct Cetartiodactyls: Results of Simultaneous Analyses of Molecular, Morphological, and Stratigraphic Data". Journal of Mammalian Evolution. 12 (1–2): 145–160. doi:10.1007/s10914-005-4963-8.
  9. Graur, D.; Higgins, G. (1994). "Molecular evidence for the inclusion of cetaceans within the order Artiodactyla" (PDF). Molecular Biology and Evolution. 11 (3): 357–364. PMID 8015431.
  10. 1 2 Samuel T Turvey; Robert L Pitman; Barbara L Taylor; Jay Barlow; Tomonari Akamatsu; Leigh A Barrett; Xiujiang Zhao; Randall R Reeves; Brent S Stewart; Kexiong Wang; Zhuo Wei; Xianfeng Zhang; L.T Pusser; Michael Richlen; John R Brandon; Ding Wang (2007). "First human-caused extinction of a cetacean species?". Biology Letters. 3 (5): 537–540. PMC 2391192Freely accessible. PMID 17686754. doi:10.1098/rsbl.2007.0292.
  11. Davidson College, biology department (2001). "Bottlenose Dolphins – Altruism". Archived from the original on January 6, 2010. Retrieved March 12, 2008.
  12. "Dolphins deserve same rights as humans, say scientists". BBC News Online. 21 Feb 2012. Retrieved 9 December 2015.
  13. D. Kraus, Scott; W. Brown, Moira; Caswell, Hal; W. Clark, Christopher; Fujiwara, Masami; K. Hamilton, Philip; D. Kenney, Robert; R. Knowlton, Amy; Landry, Scott; A. Mayo, Charles; A. McLellan, William; J. Moore, Michael; P. Nowacek, Douglas; Ann Pabst, D.; J. Read, Andrew; M. Rolland, Rosalind (2005). "North Atlantic Right Whales in Crisis". Science. 309 (5734): 561–562. PMID 16040692. doi:10.1126/science.1111200.
  14. 1 2 "The IUCN Red List of Threatened Species". International Union for Conservation of Nature and Natural Resources. Retrieved 20 January 2015.
  15. Karlsen, K. (1962). "Development of tooth germs and adjacent structures in the whalebone whale (Balaenoptera physalus)". Hvalrådets Skrifter: Scientific Results of Marine Biological Research. 45: 1–56.
  16. 1 2 3 4 5 6 7 Martin, Dr. Anthony R. (1991). Whales and Dolphins. London: Salamander Books. ISBN 0-8160-3922-4.
  17. Miyashita, T; Kato, H (1998). "Recent data on the status of right whales in the NW Pacific Ocean". International Whaling Commission. Cambridge, UK.
  18. Goldbogen, Jeremy A. (2010). "The Ultimate Mouthful: Lunge Feeding in Rorqual Whales". American Scientist. 98 (2): 124–131. doi:10.1511/2010.83.124 (inactive 2017-07-26).
  19. 1 2 "List of Marine Mammal Species and Subspecies". Society for Marine Mammalogy. May 2016. Retrieved 16 April 2017.
  20. Bjorge, Arne; A Tolley, Krystal (2008). "Harbor porpoise Phocoena phocoena". In William F. Perrin; Bernd Wursig; J. G.M. Thewissen. Encyclopedia of Marine Mammals. pp. 530–532.
  21. Wang, Yongchen (2007-01-10). "Farewell to the Baiji". China Dialogue. Retrieved 2007-05-29.
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  23. Rice, DW (1998). Marine mammals of the world: Systematics and distribution. Society for Marine Mammalogy. ISBN 978-1-891276-03-3.

Further reading

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