List of cetaceans

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Cetaceans
Temporal range: Early EocenePresent
Tursiops truncatus 01-cropped.jpg
Bottlenose dolphin breaching
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Class: Mammalia
Order: Cetartiodactyla[a]
Suborder: Whippomorpha
Infraorder: Cetacea
Subgroups

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 34-metre (112 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[b] 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[edit]

Conservation status[edit]

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[edit]

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[edit]

Main article: Mysticeti

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[edit]

See also: Balaenidae

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 name Scientific name IUCN Red List Status Global Population Estimate Range Size Picture
Bowhead whale Balaena mysticetus
Linnaeus, 1758
LC IUCN 12,682–39,950 Bowhead whale range Bowhead whale size
60 tonnes
Bowhead whale
Genus Eubalaena Gray, 1864 – 3 species
Common name Scientific name IUCN Red List Status Global Population Estimate Range Size Picture
North Atlantic right whale Eubalaena glacialis
Müller, 1776
EN IUCN 300-350 North Atlantic right whale range North Atlantic right whale size
40–80 tonnes
North Atlantic right whale
North Pacific right whale Eubalaena japonica
Lacépède, 1818
EN IUCN 404-2,108[17] North Pacific right whale range North Pacific right whale size
60–80 tonnes
North Pacific right whale
Southern right whale Eubalaena australis
Desmoulins, 1822
LC IUCN 7,500 Southern right whale range Southern right whale size
40–80 tonnes
Southern right whale

Family Balaenopteridae: rorquals[edit]

See also: Balaenopteridae

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 150 tonnes, two others that easily pass 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 name Scientific name Status Population Distribution Size Picture
Blue whale Balaenoptera musculus
Linnaeus, 1758
EN IUCN 5,000–15,000 Blue whale range Blue whale size
150-200 tonnes
Blue whale
Bryde's whale Balaenoptera brydei
Olsen, 1913
DD IUCN 90,000–100,000 Bryde's whale range Bryde's whale size
14–30 tonnes
Bryde's whale
Common minke whale Balaenoptera acutorostrata
Lacépède, 1804
LC IUCN Unknown Common minke whale range Common minke whale size
6-11 tonnes
Common minke whale
Eden's whale Balaenoptera edeni
Anderson, 1879
DD IUCN Unknown Eden's whale range Unknown Eden's whale (illustration)
Fin whale Balaenoptera physalus
Linnaeus, 1758
EN IUCN 100,000 Fin whale range Fin whale size
45–75 tonnes
Fin whale
Omura's whale Balaenoptera omurai
Wada et al., 2003
DD IUCN Unknown Unknown Unknown Omura's whale
Sei whale Balaenoptera borealis
Lesson, 1828
EN IUCN 57,000 Sei whale range Sei whale size
20–25 tonnes
Sei whales
Southern minke whale Balaenoptera bonaerensis
Burmeister, 1867
DD IUCN 515,000 Antarctic minke whale range Antarctic minke whale size
6-10 tonnes
Antarctic minke whale
Subfamily Megapterinae – 1 genus, 1 species
Genus Megaptera Gray, 1846 – 1 species
Common name Scientific name Status Population Distribution Size Picture
Humpback whale Megaptera novaeangliae
Borowski, 1781
LC IUCN 80,000 Humpback whale range Humpback whale size
25–30 tonnes
Humpback whale

Family Cetotheriidae: pygmy right whale[edit]

See also: Cetotheriidae

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 name Scientific name Status Population Distribution Size Picture
Pygmy right whale Caperea marginata
Gray, 1846
DD IUCN Unknown Pygmy right whale range Pygmy right whale size
3-3.5 tonnes
Pygmy right whale (illustration)

Family Eschrichtiidae: gray whale[edit]

See also: Eschrichtiidae

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 name Scientific name Status Population Distribution Size Picture
Gray whale Eschrichtius robustus
Lilljeborg, 1861
LC IUCN 26,000 Gray whale range Gray whale size
15–40 tonnes
Gray whale

Odontoceti: toothed whales[edit]

Main article: Odontoceti

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[edit]

See also: Delphinidae

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 name Scientific name Status Population Distribution Size Picture
Chilean dolphin Cephalorhynchus eutropia
Gray, 1846
NT IUCN Unknown Chilean dolphin range Chilean dolphin size
60 kg
Chilean dolphin
Commerson's dolphin Cephalorhynchus commersonii
Lacépède, 1804
DD IUCN 3,400 Commerson's dolphin range Commerson's dolphin size
35–60 kilograms
Commerson's dolphin
Heaviside's dolphin Cephalorhynchus heavisidii
Gray, 1828
DD IUCN Unknown Heaviside's dolphin range Heaviside's dolphin size
40–75 kg
Heaviside's dolphin
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) Hector's dolphin range (Maui's dolphin in green) Hector's dolphin size
35–60 kg
Hector's dolphin
Genus Delphinus – three species
Common name Scientific name Status Population Distribution Size Picture
Arabian common dolphin Delphinus tropicalis
van Bree, 1971
NE Unknown (cetacean needed) Arabian common dolphin size
65–105 kg
Arabian common dolphin
Long-beaked common dolphin Delphinus capensis
Gray, 1828
DD IUCN Unknown [c] Long-beaked common dolphin range Long-beaked common dolphin size
80–150 kg
Long-beaked common dolphin
Short-beaked common dolphin Delphinus delphis
Linnaeus, 1758
LC IUCN Short-beaked common dolphin range Short-beaked common dolphin size
70–110 kg
Short-beaked common dolphin
Genus Feresa – one species
Common name Scientific name Status Population Distribution Size Picture
Pygmy killer whale Feresa attenuata
Gray, 1875
DD IUCN Unknown [d] Pygmy killer whale range Pygmy killer whale size
160–350 kg
Pygmy killer whale (skeleton)
Genus Globicephala – two species
Common name Scientific name Status Population Distribution Size Picture
Long-finned pilot whale Globicephala melas
Traill, 1809
DD IUCN Unknown [e] Long-finned pilot whale range Long-finned pilot whale size
3-3.5 tonnes
Long-finned pilot whale
Short-finned pilot whale Globicephala macrorhynchus
Gray, 1846
DD IUCN Unknown [f] Short-finned pilot whale range Short-finned pilot whale size
1–3 tonnes
Short-finned pilot whale
Genus Grampus – one species
Common name Scientific name Status Population Distribution Size Picture
Risso's dolphin Grampus griseus
G. Cuvier, 1812
LC IUCN Unknown [g] Risso's dolphin range Risso's dolphin size
300 kg
Risso's dolphin
Genus Lagenodelphis – one species
Common name Scientific name Status Population Distribution Size Picture
Fraser's dolphin Lagenodelphis hosei
Fraser, 1956
LC IUCN Unknown Fraser's dolphin range Fraser's dolphin size
209 kg
Fraser's dolphin
Genus Lagenorhynchus Gray, 1846 – six species
Common name Scientific name Status Population Distribution Size Picture
Atlantic white-sided dolphin Lagenorhynchus acutus
Gray, 1828
LC IUCN 200,000 – 300,000 Atlantic white-sided dolphin range Atlantic white-sided dolphin size
235 kg
Atlantic white-sided dolphin
Dusky dolphin Lagenorhynchus obscurus
Gray, 1828
DD IUCN Unknown Dusky dolphin range Dusky dolphin size
100 kg
Dusky dolphin
Hourglass dolphin Lagenorhynchus cruciger
Quoy & Gaimard, 1824
LC IUCN 140,000 Hourglass dolphin range Hourglass dolphin size
90–120 kg
Hourglass dolphin
Pacific white-sided dolphin Lagenorhynchus obliquidens
Gill, 1865
LC IUCN 1,000,000 Pacific white-sided dolphin range Pacific white-sided dolphin size
85–150 kg
Pacific white-sided dolphin
Peale's dolphin Lagenorhynchus australis
Peale, 1848
DD IUCN Unknown [h] Peale's dolphin range Peale's dolphin size
115 kg
Peale's dolphin
White-beaked dolphin Lagenorhynchus albirostris
Gray, 1846
LC IUCN 100,000 [i] White-beaked dolphin range White beaked dolphin size
180 kg
White-beaked dolphin
Genus Lissodelphis – two species
Common name Scientific name Status Population Distribution Size Picture
Northern right whale dolphin Lissodelphis borealis
Peale, 1848
LC IUCN 400,000 [j] Northern right whale dolphin range Northern right whale dolphin size
115 kg
Northern right whale dolphin
Southern right whale dolphin Lissodelphis peronii
Lacépède, 1804
DD IUCN Unknown [k] Southern right whale dolphin range Southern right whale dolphin size
60–100 kg
Southern right whale dolphin
Genus Orcaella Gray, 1866 – two species
Common name Scientific name Status Population Distribution Size Picture
Australian snubfin dolphin Orcaella heinsohni
Beasley, Robertson & Arnold, 2005
NT IUCN Unknown Australian snubfin dolphin range Australian snubfin dolphin size
130–145 kg
Australian snubfin dolphin
Irrawaddy dolphin Orcaella brevirostris
Gray, 1866
VU IUCN Unknown Irrawaddy dolphin range Irrawaddy dolphin size
130 kg
Irrawaddy dolphin
Genus Orcinus – one species
Common name Scientific name Status Population Distribution Size Picture
Killer whale Orcinus orca
Linnaeus, 1758
DD IUCN 100,000 [l] Killer whale range Killer whale size
4.5 tonnes
Killer whale
Genus Peponocephala – one species
Common name Scientific name Status Population Distribution Size Picture
Melon-headed whale Peponocephala electra
Gray, 1846
LC IUCN Unknown [m] Melon-headed whale range Melon-headed whale size
225 kg
Melon-headed whale
Genus Pseudorca – one species
Common name Scientific name Status Population Distribution Size Picture
False killer whale Pseudorca crassidens
Owen, 1846
DD IUCN Unknown [n] False killer whale range False killer whale size
1.5-2 tonnes
False killer whale
Genus Sousa – three species
Common name Scientific name Status Population Distribution Size Picture
Atlantic humpback dolphin Sousa teuszi
Kükenthal, 1892
DD IUCN Unknown Atlantic humpback dolphin range Atlantic humpback dolphin size
100–150 kg
(cetacean needed)
Indian humpback dolphin Sousa plumbea
Cuvier, 1829
DD Unknown Indian humpback dolphin range Indian humpback dolphin size
150–200 kg
Indian humpback dolphin
Pacific humpback dolphin Sousa chinensis
Osbeck, 1765
DD IUCN Unknown Pacific humpback dolphin range Pacific humpback dolphin size
250–280 kg
Pacific humpback dolphin
Genus Sotalia – two species
Common name Scientific name Status Population Distribution Size Picture
Costero Sotalia guianensis
Bénéden, 1864
DD IUCN Unknown Costero range
Solid color
Costero size
35–45 kg
Costero
Tucuxi Sotalia fluviatilis
Gervais & Deville, 1853
DD IUCN Unknown Tucuxi range
Hashed color
Tucuxi size
35–45 kg
Tucuxi
Genus Stenella Gray, 1866 – five species
Common name Scientific name Status Population Distribution Size Picture
Atlantic spotted dolphin Stenella frontalis
Cuvier, 1829
DD IUCN 100,000 Atlantic spotted dolphin range Atlantic spotted dolphin size
100 kg
Atlantic spotted dolphin
Clymene dolphin Stenella clymene
Gray, 1846
DD IUCN Unknown Clymene dolphin range Clymene dolphin size
75–80 kg
Clymene dolphin
Pantropical spotted dolphin Stenella attenuata
Gray, 1846
CD IUCN 3,000,000 Pantropical spotted dolphin range Pantropical spotted dolphin size
100 kg
Pantropical spotted dolphin
Spinner dolphin Stenella longirostris
Gray, 1828
DD IUCN Unknown Spinner dolphin range Spinner dolphin size
90 kg
Spinner dolphin
Striped dolphin Stenella coeruleoalba
Meyen, 1833
CD IUCN 2,000,000 Striped dolphin range Striped dolphin size
100 kg
Striped dolphin
Genus Steno – one species
Common name Scientific name Status Population Distribution Size Picture
Rough-toothed dolphin Steno bredanensis
Lesson, 1828
LC IUCN 150,000 Rough-toothed dolphin range Rough-toothed dolphin size
100–135 kg
Rough-toothed dolphin
Genus Tursiops – three species
Common name Scientific name Status Population Distribution Size Picture
Burrunan dolphin Tursiops australis NE Unknown Burrunan dolphin
Common bottlenose dolphin Tursiops truncatus
Montagu, 1821
LC IUCN Unknown Common bottlenose dolphin range Common bottlenose dolphin size
150–650 kg
Common bottlenose dolphin
Indo-Pacific bottlenose dolphin Tursiops aduncus
Ehrenberg, 1833
DD IUCN Unknown Indo-Pacific dolphin range
230 kg
Indo-Pacific dolphin

Family Monodontidae: narwhal and beluga[edit]

See also: Monodontidae

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 name Scientific name Status Population Distribution Size Picture
Beluga Delphinapterus leucas
Pallas, 1776
NT IUCN 100,000 [o] Beluga whale range Beluga whale size
1.5 tonnes
Beluga whale
Genus Monodon – one species
Common name Scientific name Status Population Distribution Size Picture
Narwhal(e) Monodon monoceros
Linnaeus, 1758
NT IUCN 25,000 [p] Narwhal range Narwhal size
900-1,500 kilograms
Narwhal

Family Kogiidae: dwarf and pygmy sperm whales[edit]

See also: Kogiidae

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 name Scientific name Status Population Distribution Size Picture
Dwarf sperm whale Kogia sima
Owen, 1866
DD IUCN Unknown [q] Dwarf sperm whale range Dwarf sperm whale size
250 kg
Dwarf sperm whale (reconstruction)
Pygmy sperm whale Kogia breviceps
Blainville, 1838
DD IUCN Unknown [r] Pygmy sperm whale range Pygmy sperm whale size
400 kg
Pygmy sperm whale

Family Phocoenidae: porpoises[edit]

See also: Phocoenidae

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 name Scientific name Status Population Distribution Size Picture
Indo-pacific finless porpoise Neophocaena phocaenoides
Cuvier, 1829
VU IUCN[s] Unknown [t] Indo-pacific finless porpoise range Indo-pacific finless porpoise size
30–45 kg
Indo-pacific finless porpoise (skeleton)
Narrow-ridged finless porpoise Neophocaena asiaeorientalis
Cuvier, 1829
CR IUCN[u] 1,000 Narrow-ridged finless porpoise range (red color)
red color
Finless porpoise size
30–45 kg
Narrow-ridged finless porpoise
Genus Phocoena – four species
Common name Scientific name Status Population Distribution Size Picture
Burmeister's porpoise Phocoena spinipinnis
Burmeister, 1865
DD IUCN Unknown [v] Burmeister's porpoise range Burmeister's porpoise size
50–75 kg
(cetacean needed)
Harbour porpoise Phocoena phocoena
Linnaeus, 1758
LC IUCN 700,000 [19] Harbour porpoise range Harbour porpoise size
75 kg
Harbour porpoise
Spectacled porpoise Phocoena dioptrica
Lahille, 1912
DD IUCN Unknown [w] Spectacled porpoise range Spectacled porpoise size
60–84 kg
(cetacean needed)
Vaquita Phocoena sinus
Norris & McFarland, 1958
CR IUCN 500 [x] Vaquita range Vaquita size
50 kg
Vaquita
Genus Phocoenoides – 1 species
Common name Scientific name Status Population Distribution Size Picture
Dall's porpoise Phocoenoides dalli
True, 1885
LC IUCN 1,100,000 [y] Dall's porpoise range Dall's porpoise size
130–200 kg
Dall's porpoise

Family Physeteridae: sperm whale[edit]

See also: Physeteridae

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 name Scientific name Status Population Distribution Size Picture
Sperm whale Physeter macrocephalus
Linnaeus, 1758
VU IUCN 200,000–2,000,000 [z] Sperm whale range Sperm whale size
25–50 tonnes
Sperm whale

Family Ziphiidae: beaked whales[edit]

See also: Ziphiidae

A beaked whale is any of at least 21 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 name Scientific name Status Population Distribution Size Picture
Arnoux's beaked whale Berardius arnuxii
Duvernoy, 1851
DD IUCN Unknown [aa] Arnoux's beaked whale range Arnoux's beaked whale size
8 tonnes
Arnoux's beaked whale
Baird's beaked whale Berardius bairdii
Stejneger, 1883
DD IUCN Unknown [ab] Baird's beaked whale range Baird's beaked whale size
12 tonnes
(cetacean needed)
Genus Tasmacetus – one species
Common name Scientific name Status Population Distribution Size Picture
Shepherd's beaked whale Tasmacetus shepherdi
Oliver, 1937
DD IUCN Unknown [ac] Shepherd's beaked whale range Shepherd's beaked whale size
2-2.5 tonnes
(cetacean needed)
Genus Ziphius – one species
Common name Scientific name Status Population Distribution Size Picture
Cuvier's beaked whale Ziphius cavirostris
G. Cuvier, 1823
LC Unknown [ad] Cuvier's beaked whale range Cuvier's beaked whale size
2–3 tonnes
Cuvier's beaked whale
Subfamily Hyperoodontinae – three genera, 17 species
Genus Hyperoodon – two species
Common name Scientific name Status Population Distribution Size Picture
Northern bottlenose whale Hyperoodon ampullatus
Forster, 1770
DD IUCN 10,000 [ae] Northern bottlenose whale range Northern bottlenose whale size
7 tonnes
Northern bottlenose whale
Southern bottlenose whale Hyperoodon planifrons
Flower, 1882
LC IUCN 500,000 Southern bottlenose range Southern bottlenose whale size
6 tonnes
(cetacean needed)
Genus Indopacetus – one species
Common name Scientific name Status Population Distribution Size Picture
Tropical bottlenose whale Indopacetus pacificus
Longman, 1926
DD IUCN Unknown [af] Tropical bottlenose whale range Tropical bottlenose whale size
3,5-4 tonnes
(cetacean needed)
Genus Mesoplodon Gervais, 1850 – 14 species
Common name Scientific name Status Population Distribution Size Picture
Andrews' beaked whale Mesoplodon bowdoini
Andrews, 1908
DD IUCN Unknown Andrew's beaked whale range Andrew's beaked whale size
1 tonne
Andrew's beaked whale (skeleton)
Blainville's beaked whale Mesoplodon densirostris
Blainville, 1817
DD IUCN Unknown Blainville's beaked whale range Blainville's beaked whale size Blainville's beaked whale
Gervais' beaked whale Mesoplodon europaeus
Gervais, 1855
DD IUCN Unknown Gervais' beaked whale range Gervais' beaked whale
1.2 tonnes
(cetacean needed)
Ginkgo-toothed beaked whale Mesoplodon ginkgodens
Nishiwaki & Kamiya, 1958
DD IUCN Unknown Ginkgo-toothed beaked whale range Ginkgo-toothed beaked whale size
1.5 tonnes
Ginkgo-toothed beaked whale (skull)
Gray's beaked whale Mesoplodon grayi
von Haast, 1876
DD IUCN Unknown Gray's beaked whale range Gray's beaked whale size
1.5 tonnes
Gray's beaked whale
Hector's beaked whale Mesoplodon hectori
Gray, 1871
DD IUCN Unknown Hector's beaked whale range Hector's beaked whale size
1 tonne
Hector's beaked whale
Hubbs' beaked whale Mesoplodon carlhubbsi
Moore, 1963
DD IUCN Unknown Hubb's beaked whale range Hubb's beaked whale size
1.4 tonnes
(cetacean needed)
Perrin's beaked whale Mesoplodon perrini
Dalebout, Mead, Baker, Baker, & van Helding, 2002
DD IUCN Unknown (cetacean needed) Perrin's beaked whale size
1.3–1.5 tonnes
(cetacean needed)
Pygmy beaked whale Mesoplodon peruvianus
Reyes, Mead, and Van Waerebeek, 1991
DD IUCN Unknown Pygmy beaked whale range Pygmy beaked whale size
800 kg
(cetacean needed)
Sowerby's beaked whale Mesoplodon bidens
Sowerby, 1804
VU IUCN Unknown Sowerby's beaked whale range Sowerby's beaked whale size
1-1.3 tonnes
Sowerby's beaked whale
Spade-toothed whale Mesoplodon traversii, syn. Mesoplodon bahamondi
Gray, 1874
DD IUCN Unknown Spade-toothed whale range Spade-toothed whale size
1.2 tonnes
(cetacean needed)
Stejneger's beaked whale Mesoplodon stejnegeri
True, 1885
DD IUCN Unknown Stejneger's beaked whale range Stejneger's beaked whale size
1.5 tonnes
Stejneger's beaked whale (skull)
Strap-toothed whale Mesoplodon layardii
Gray, 1865
DD IUCN Unknown Strap-toothed whale range Strap-toothed whale size
2 tonnes
Strap-toothed whale (skull)
True's beaked whale Mesoplodon mirus
True, 1913
DD IUCN Unknown True's beaked whale range True's beaked whale size
1.4 tonnes
True's beaked whale

Superfamily Platanistoidea: river dolphins[edit]

See also: Platanistoidea

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[edit]

Main article: Iniidae

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

  • I. geoffrensis geoffrensis – Amazon basin population (excluding Madeira river drainage area, above the Teotonio Rapids in Bolivia)
  • I. geoffrensis humboldtiana – Orinoco basin population
  • Bolivian river dolphinI. g. boliviensis – Amazon basin population in the Madeira drainage area


Genus Inia – two species
Common name Scientific name Status Population Distribution Size Picture
Amazon river dolphin Inia geoffrensis
Blainville, 1817
DD IUCN Unknown Amazon river dolphin range Amazon river dolphin size
150 kg
Amazon river dolphin
Araguaian river dolphin Inia araguaiaensis
Hrbek, Da Silva, Dutra, Farias, 2014
NE Unknown Araguaian river dolphin range
Araguaian river dolphin in blue
Araguaian river dolphin size
150 kg
Araguaian river dolphin

Family Lipotidae: baiji[edit]

Main article: Lipotidae

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.[20] The species was declared functionally extinct in 2006 after an expedition to record population numbers found no specimens.

Genus Lipotes – one species
Common name Scientific name Status Population Distribution Size Picture
Baiji Lipotes vexillifer
Miller, 1918
CR IUCN 13 [ag] Baiji range Baiji size
130 kg
Baiji (illustration)

Family Platanistidae: South Asian river dolphin[edit]

Main article: Platanistidae

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.[21] 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 dolphin) and P. g. gangetica (the Ganges river dolphin).[22]

Genus Platanista – one species
Common name Scientific name Status Population Distribution Size Picture
South Asian river dolphin Platanista gangetica
Roxburgh, 1801
EN IUCN 1,100 [ah] South Asian river dolphin range South Asian river dolphin size
200 kg
South Asian river dolphin (skeleton)

Family Pontoporiidae: La Plata river dolphin[edit]

Main article: Pontoporiidae

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

Genus Pontoporia – one species
Common name Scientific name Status Population Distribution Size Picture
La Plata dolphin Pontoporia blainvillei
Gervais & d'Orbigny, 1844
VU IUCN 4,000–4,500 La Plata dolphin range La Plata dolphin size
50 kg
La Plata dolphin (skeleton)

See also[edit]

Footnotes[edit]

  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. ^ The total population is unknown but numbers in the hundreds of thousands
  4. ^ The only population estimate is of 38,900 individuals in the eastern tropical Pacific Ocean
  5. ^ 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
  6. ^ 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
  7. ^ 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
  8. ^ Total population unknown but thought to be locally common – it is the most common dolphin found around the Falkland Islands
  9. ^ Estimates of various stocks throughout the North Atlantic give an overall value into the high tens or low hundreds of thousands
  10. ^ Varying population estimates for areas around California and the North Pacific give a total of up to 400,000
  11. ^ Surveys suggest this is the most common dolphin off of Chilean waters
  12. ^ 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
  13. ^ 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
  14. ^ 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
  15. ^ 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
  16. ^ 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
  17. ^ No global population estimates have been made. One survey estimated a population of about 11,000 in the eastern Pacific
  18. ^ No global population estimates have been made. One survey estimated a population of about 11,000 in the eastern Pacific
  19. ^ There is not enough data to place finless porpoises on the endangered species list
  20. ^ 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
  21. ^ In China, they are endangered. Their propensity for staying close to shore places them in great danger from fishing
  22. ^ There are no quantitative data on abundance
  23. ^ 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
  24. ^ 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
  25. ^ The most recent estimate for the North Pacific and Bering Sea is 1,186,000
  26. ^ 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
  27. ^ Arnoux's beaked whales seem to be relatively abundant in Cook Strait during summer
  28. ^ Virtually nothing is known about the abundance of Baird's beaked whales, except they are not rare as was formerly thought
  29. ^ Nothing is known about the relative abundance of this species or its population composition
  30. ^ Because of the difficulty of identifying the species the total global population is unknown
  31. ^ Total population is unknown but likely to be of the order of 10,000
  32. ^ A 2002 survey estimates there are 766 animals around Hawaii. No other population estimates exist for other locales
  33. ^ 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
  34. ^ Estimates give values of 1,100 Indus river dolphins and maybe as few as 20 Ganges river dolphins

References[edit]

  1. ^ a b Agnarsson, I.; May-Collado, LJ. (2008). "The phylogeny of Cetartiodactyla: the importance of dense taxon sampling, missing data, and the remarkable promise of cytochrome b to provide reliable species-level phylogenies". Mol Phylogenet Evol. 48 (3): 964–985. doi:10.1016/j.ympev.2008.05.046. PMID 18590827. 
  2. ^ a b 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. doi:10.1017/s1464793105006743. PMID 16094808. 
  3. ^ a b 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. doi:10.1093/oxfordjournals.molbev.a025792. PMID 9159933. 
  4. ^ a b 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. doi:10.1371/journal.pone.0007062. PMC 2740860. PMID 19774069. 
  5. ^ a b "Cetacean Species and Taxonomy". IUCN-SSC: Cetacean Specialist Group. Retrieved December 14, 2015. 
  6. ^ a b "List of Marine Mammal Species and Subspecies". Society for Marine Mammalogy. 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. ^ a b 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. doi:10.1098/rsbl.2007.0292. PMC 2391192. PMID 17686754. 
  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. doi:10.1126/science.1111200. 
  14. ^ a b "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. ^ a b c d e f g 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. 
  19. ^ 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. 
  20. ^ Wang, Yongchen (2007-01-10). "Farewell to the Baiji". China Dialogue. Retrieved 2007-05-29. 
  21. ^ Pilleri, G., Marcuzzi, G. and Pilleri, O., 1982. Speciation in the Platanistoidea, systematic, zoogeographical and ecological observations on recent species. Investigations on Cetacea, 14: 15–46.
  22. ^ Rice, DW (1998). Marine mammals of the world: Systematics and distribution. Society for Marine Mammalogy. ISBN 978-1-891276-03-3. 

Further reading[edit]

External links[edit]