List of cetaceans
From Wikipedia, the free encyclopedia
| Cetaceans Fossil range: Early Eocene - Recent |
||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
 Bottlenose Dolphin breaching
|
||||||||||
| Scientific classification | ||||||||||
|
This is a list of cetaceans. The order Cetacea includes whales, dolphins, and porpoises. It has just over eighty living species, divided into the suborders Odontoceti (the toothed whales, including dolphins and porpoises) and Mysticeti (the baleen whales). In addition, numerous species of extinct cetaceans exist, but they are not listed here. This list contains only the known, extant cetacean species including several recent discoveries (the Baiji is also included though it is believed to have gone extinct in 2006).
Cetaceans are aquatic mammals characterised by having a fusiform (streamlined) body shape, paddle-shaped front limbs and vestigial hind limbs. The tail has been flattened into a fluke to aid propulsion.
Contents
|
[edit] Suborder Mysticeti: baleen whales
The baleen whales, also called whalebone whales or great whales, form the Mysticeti, one of two suborders of the Cetacea (whales, dolphins and porpoises). Baleen whales are characterized by having baleen plates for filtering food from water, rather than having teeth, like with the Odontocetes. This distinguishes them from the other suborder of cetaceans, the toothed whales or Odontoceti. Living Mysticeti species have teeth only during the embryonal phase. Fossil Mysticeti had teeth before baleen evolved.
Family Balaenidae: Right Whales
- See also: Balaenidae
Balaenidae is a family of cetaceans that contains two genera. Commonly called the Right Whales as it contains mainly Right Whale species. This name can be confusing, however, since one of the species is the Bowhead Whale, which is different to the Right Whale. All the Balaenidae whales have the following features: a smooth belly and chin, with no ventral grooves; a distinctive head shape with strongly arched, narrow rostrum (anatomy) and bowed lower jaw; lower lips that enfold the sides and front of the rostrum; long, narrow, elastic baleen plates (up to 9 times longer longer than wide) with fine baleen fringes; the fusion of all the cervical vertebrae and other skeletal characteristics; a slow swimming speed.[1]
| Genus Balaena Linnaeus, 1758 - 1 species | ||||||
| Common name | Scientific name | Status | Population | Distribution | Size | Picture |
|---|---|---|---|---|---|---|
| Bowhead Whale | Balaena mysticetus Linnaeus, 1758 |
Conservation Dependent (LR/cd) | 8,000-9,200 |  |
 60 tonnes |
 |
| Genus Eubalaena Gray, 1864 - 3 species | ||||||
| Common name | Scientific name | Status | Population | Distribution | Size | Picture |
| North Atlantic Right Whale | Eubalaena glacialis Müller, 1776 |
Endangered (EN) | 300 |  |
 40-80 tonnes |
 |
| North Pacific Right Whale | Eubalaena japonica Lacépède, 1818 |
Endangered (EN) | 200 |  |
60-80 tonnes |
 |
| Southern Right Whale | Eubalaena australis Desmoulins, 1822 |
Conservation Dependent (LR/cd) | 7,000 |  |
40-80 tonnes |
 |
[edit] Family Balaenopteridae: Rorquals
- See also: Balaenopteridae
Rorquals are the largest group of baleen whales, with nine 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.
Rorquals 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.
All rorquals have ventral grooves, and are the only cetaceans to have them. Additionally, they all have a dorsal fin, a broad, gently curving rostrum and short baleen plates.[1]
| Subfamily Balaenopterinae - 1 genus, 8 species | ||||||
| Genus Balaenoptera - 8 species | ||||||
| Common name | Scientific name | Status | Population | Distribution | Size | Picture |
|---|---|---|---|---|---|---|
| Fin Whale | Balaenoptera physalus Linnaeus, 1758 |
Endangered (EN) | 64,000 |  |
 45-75 tonnes |
 |
| Sei Whale | Balaenoptera borealis Lesson, 1828 |
Endangered (EN) | 57,000 |  |
 20-25 tonnes |
 |
| Bryde's Whale | Balaenoptera brydei Olsen, 1913 |
Unknown | Unknown |  |
 16-18.5 tonnes |
 |
| Pygmy Bryde's Whale | Balaenoptera edeni Anderson, 1879 |
Unknown | Unknown | 12 tonnes | ||
| Blue Whale | Balaenoptera musculus Linnaeus, 1758 |
Endangered (EN) | 5,000-12,000 |  |
 100-120 tonnes |
 |
| Northern Minke Whale | Balaenoptera acutorostrata Lacépède, 1804 |
Near Threatened (LR/nt) | Unknown |  |
 9 tonnes |
 |
| Southern Minke Whale | Balaenoptera bonaerensis Burmeister, 1867 |
Conservation Dependent (LR/cd) | Unknown |  |
9 tonnes |
|
| No common name in usage | Balaenoptera omurai Wada et al., 2003 |
Unknown | Unknown | |||
| 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 |
Vulnerable (VU) | 5,000-7,500 |  |
 25-30 tonnes |
 |
[edit] Family Eschrichtiidae: Gray Whale
- 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.[1]
| Genus Eschrichtius - 1 species | ||||||
| Common name | Scientific name | Status | Population | Distribution | Size | Picture |
|---|---|---|---|---|---|---|
| Gray Whale | Eschrichtius robustus Lilljeborg, 1861 |
Conservation Dependent (LR/cd) | 26,000 |  |
 14-35 tonnes |
 |
[edit] Family Neobalaenidae: Pygmy Right Whale
- See also: Neobalaenidae
The Pygmy Right Whale shares several characteristics with the Right Whales although what separates them from Right Whales is that they have a dorsal fin, and they have a very distinctive jaw configuration. Pygmy Right Whales also have a head no more than ¼ the size of their body, whereas the Right Whales have heads approximately ⅓ the size of their body.[1]
| Genus Caperea Gray, 1864 - 1 species | ||||||
| Common name | Scientific name | Status | Population | Distribution | Size | Picture |
|---|---|---|---|---|---|---|
| Pygmy Right Whale | Caperea marginata Gray, 1846 |
Least Concern (LR/lc) | Unknown |  |
 3-3.5 tonnes |
[edit] Suborder Odontoceti: toothed whales
The toothed whales (systematic name Odontoceti) form a suborder of the cetaceans. As the name suggests, the suborder is characterized by having teeth (rather than baleen). Toothed whales are active hunters, feeding on fish, squid, and in some cases other marine mammals.
[edit] Family Delphinidae: oceanic dolphins
- See also: Delphinidae
Oceanic dolphins are the members of the Delphinidae family of cetaceans. 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 Orca and its relatives, are commonly called whales, rather than dolphins. They are also sometimes collectively known as "blackfish".
The Delphinidae are characterised by having a distinct beak (unlike the Porpoises), two or more fused cervical vertebrae and 20 or more pairs of teeth in the upper jaw. None are more than 4 metres long.[1]
| Genus Cephalorhynchus Gray, 1846 - 4 species | ||||||
| Common name | Scientific name | Status | Population | Distribution | Size | Picture |
|---|---|---|---|---|---|---|
| Commerson's Dolphin | Cephalorhynchus commersonii Lacépède, 1804 |
Data deficient | 3,400 |  |
 35-60 kilograms |
 |
| Chilean Dolphin | Cephalorhynchus eutropia Gray, 1846 |
Data deficient | Unknown |  |
 60 kilograms |
|
| Heaviside's Dolphin | Cephalorhynchus heavisidii Gray, 1828 |
Data deficient | Unknown |  |
 40-75 kilograms |
|
| Hector's Dolphin | Cephalorhynchus hectori Van Beneden, 1881 |
Endangered (EN) | 2,000-2,500 |  |
 35-60 kilograms |
 |
| Genus Steno - 1 species | ||||||
| Common name | Scientific name | Status | Population | Distribution | Size | Picture |
| Rough-toothed Dolphin | Steno bredanensis Lesson, 1828 |
Data deficient | 150,000 |  |
 100-135 kilograms |
 |
| Genus Sousa - 3 species | ||||||
| Common name | Scientific name | Status | Population | Distribution | Size | Picture |
| Atlantic Humpback Dolphin | Sousa teuszi Kükenthal, 1892 |
Data deficient | Unknown |  |
 100-150 kilograms |
|
| Indian Humpback Dolphin | Sousa plumbea Cuvier, 1829 |
Data deficient | Unknown |  |
150-200 kilograms |
|
| Pacific Humpback Dolphin | Sousa chinensis Osbeck, 1765 |
Data deficient | Unknown |  |
250-280 kilograms |
|
| Genus Sotalia - 1 species | ||||||
| Common name | Scientific name | Status | Population | Distribution | Size | Picture |
| Tucuxi | Sotalia fluviatilis Gervais & Deville, 1853 |
Data deficient | Unknown |  |
 35-45 kilograms |
|
| Genus Tursiops - 2 species | ||||||
| Common name | Scientific name | Status | Population | Distribution | Size | Picture |
| Bottlenose Dolphin | Tursiops truncatus Montagu, 1821 |
Data deficient | Unknown |  |
 150-650 kilograms |
 |
| Indian Ocean Bottlenose Dolphin | Tursiops aduncus Ehrenberg, 1833 |
Data deficient | Unknown | |
150-650 kilograms |
|
| Genus Stenella Gray, 1866 - 5 species | ||||||
| Common name | Scientific name | Status | Population | Distribution | Size | Picture |
| Pantropical Spotted Dolphin | Stenella attenuata Gray, 1846 |
Conservation Dependent (LR/cd) | 3,000,000 |  |
 100 kilograms |
 |
| Atlantic Spotted Dolphin | Stenella frontalis Cuvier, 1829 |
Data deficient | 100,000 |  |
 100 kilograms |
|
| Spinner Dolphin | Stenella longirostris Gray, 1828 |
Conservation Dependent (LR/cd) | Unknown |  |
 90 kilograms |
 |
| Clymene Dolphin | Stenella clymene Gray, 1846 |
Data deficient | Unknown |  |
 75-80 kilograms |
|
| Striped Dolphin | Stenella coeruleoalba Meyen, 1833 |
Conservation Dependent (LR/cd) | 2,000,000 |  |
 100 kilograms |
 |
| Genus Delphinus - 3 species | ||||||
| Common name | Scientific name | Status | Population | Distribution | Size | Picture |
| Short-beaked Common Dolphin | Delphinus delphis Linnaeus, 1758 |
Conservation Dependent (LR/cd) | Unknown[2] |  |
 75-130 kilograms |
 |
| Long-beaked Common Dolphin | Delphinus capensis Gray, 1828 |
Conservation Dependent (LR/cd) | Unknown[3] |  |
70-110 kilograms |
|
| Arabian Common Dolphin | Delphinus tropicalis van Bree, 1971 |
Unknown | Unknown | |||
| Genus Lagenodelphis - 1 species | ||||||
| Common name | Scientific name | Status | Population | Distribution | Size | Picture |
| Fraser's Dolphin | Lagenodelphis hosei Fraser, 1956 |
Data deficient | Unknown |  |
 209 kilograms |
 |
| Genus Lagenorhynchus Gray, 1846 - 6 species | ||||||
| Common name | Scientific name | Status | Population | Distribution | Size | Picture |
| White-beaked Dolphin | Lagenorhynchus albirostris Gray, 1846 |
Least Concern (LR/lc) | 100,000[4] |  |
 180 kilograms |
 |
| Atlantic White-sided Dolphin | Lagenorhynchus acutus Gray, 1828 |
Least Concern (LR/lc) | 200,000 - 300,000 |  |
 235 kilograms |
 |
| Pacific White-sided Dolphin | Lagenorhynchus obliquidens Gill, 1865 |
Least Concern (LR/lc) | 1,000,000 |  |
 85-150 kilograms |
 |
| Dusky Dolphin | Lagenorhynchus obscurus Gray, 1828 |
Data deficient | Unknown |  |
 100 kilograms |
 |
| Peale's Dolphin (also known as Black-chinned Dolphin) | Lagenorhynchus australis Peale, 1848 |
Data deficient | Unknown[5] |  |
 115 kilograms |
|
| Hourglass Dolphin | Lagenorhynchus cruciger Quoy & Gaimard, 1824 |
Least Concern (LR/lc) | 140,000 |  |
 90-120 kilograms |
|
| Genus Lissodelphis - 2 species | ||||||
| Common name | Scientific name | Status | Population | Distribution | Size | Picture |
| Northern Right Whale Dolphin | Lissodelphis borealis Peale, 1848 |
Least Concern (LR/lc) | 400,000[6] |  |
 115 kilograms |
 |
| Southern Right Whale Dolphin | Lissodelphis peronii Lacépède, 1804 |
Data deficient | Unknown[7] |  |
 60-100 kilograms |
|
| Genus Grampus - 1 species | ||||||
| Common name | Scientific name | Status | Population | Distribution | Size | Picture |
| Risso's Dolphin | Grampus griseus G. Cuvier, 1812 |
Data deficient | Unknown[8] |  |
 300 kilograms |
 |
| Genus Peponocephala - 1 species | ||||||
| Common name | Scientific name | Status | Population | Distribution | Size | Picture |
| Melon-headed Whale | Peponocephala electra Gray, 1846 |
Least Concern (LR/lc) | Unknown[9] |  |
 225 kilograms |
 |
| Genus Feresa - 1 species | ||||||
| Common name | Scientific name | Status | Population | Distribution | Size | Picture |
| Pygmy Killer Whale | Feresa attenuata Gray, 1875 |
Data deficient | Unknown[10] |  |
 160-350 kilograms |
|
| Genus Pseudorca - 1 species | ||||||
| Common name | Scientific name | Status | Population | Distribution | Size | Picture |
| False Killer Whale | Pseudorca crassidens Owen, 1846 |
Least Concern (LR/lc) | Unknown[11] |  |
 1.5-2 tonnes |
 |
| Genus Orca - 1 species | ||||||
| Common name | Scientific name | Status | Population | Distribution | Size | Picture |
| Orca | Orcinus orca Linnaeus, 1758 |
Conservation Dependent (LR/cd) | 100,000[12] |  |
 4.5 tonnes |
 |
| Genus Globicephala - 2 species | ||||||
| Common name | Scientific name | Status | Population | Distribution | Size | Picture |
| Short-finned Pilot Whale | Globicephala macrorhynchus Gray, 1846 |
Conservation Dependent (LR/cd) | Unknown[13] |  |
 1-3 tonnes |
|
| Long-finned Pilot Whale | Globicephala melas Traill, 1809 |
Least Concern (LR/lc) | Unknown[14] |  |
 3-3.5 tonnes |
 |
| Genus Orcaella Gray, 1866 - 2 species | ||||||
| Common name | Scientific name | Status | Population | Distribution | Size | Picture |
| Irrawaddy Dolphin | Orcaella brevirostris Gray, 1866 |
Data deficient | Unknown |  |
 130 kilograms |
|
| Australian Snubfin Dolphin | Orcaella heinsohni Beasley, Robertson & Arnold, 2005 |
Unknown | Unknown |  |
[edit] Family Monodontidae: Narwhal and Beluga
- 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 a dorsal fin which has been replaced by a tough fibrous ridge just behind the midpoint of the body and is 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 the head to be turned independently of the body. None have any throat grooves.[1]
| Genus Monodon - 1 species | ||||||
| Common name | Scientific name | Status | Population | Distribution | Size | Picture |
|---|---|---|---|---|---|---|
| Narwhal | Monodon monoceros Linnaeus, 1758 |
Data deficient | 25,000[15] |  |
 900-1,500 kilograms |
 |
| Genus Delphinapterus - 1 species | ||||||
| Common name | Scientific name | Status | Population | Distribution | Size | Picture |
| Beluga | Delphinapterus leucas Pallas, 1776 |
Vulnerable (VU) | 100,000[16] |  |
 1.5 tonnes |
 |
[edit] Family Phocoenidae: Porpoises
- See also: Phocoenidae
The 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 that 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 six species have small flippers, notched tail flukes, and no beak. All carry at least 11 pairs of small teeth in the upper and lower jaws.
Porpoises, divided into six 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 - 1 species | ||||||
| Common name | Scientific name | Status | Population | Distribution | Size | Picture |
|---|---|---|---|---|---|---|
| Finless Porpoise | Neophocaena phocaenoides Cuvier, 1829 |
Data deficient[17] | Unknown[18] |  |
 30-45 kilograms |
|
| Genus Phocoena - 4 species | ||||||
| Common name | Scientific name | Status | Population | Distribution | Size | Picture |
| Harbour Porpoise | Phocoena phocoena Linnaeus, 1758 |
Vulnerable (VU) | Unknown[19] |  |
 75 kilograms |
 |
| Vaquita | Phocoena sinus Norris & McFarland, 1958 |
Critically Endangered (CR) | 500[20] |  |
 50 kilograms |
|
| Spectacled Porpoise | Phocoena dioptrica Lahille, 1912 |
Data deficient | Unknown[21] |  |
 60-84 kilograms |
|
| Burmeister's Porpoise | Phocoena spinipinnis Burmeister, 1865 |
Data deficient | Unknown[22] |  |
 50-75 kilograms |
|
| Genus Phocoenoides - 1 species | ||||||
| Common name | Scientific name | Status | Population | Distribution | Size | Picture |
| Dall's Porpoise | Phocoenoides dalli True, 1885 |
Conservation Dependent (LR/cd) | 1,100,000[23] |  |
 130-200 kilograms |
 |
[edit] Family Physeteridae: Sperm Whale
- See also: Physeteridae
The Sperm Whale characteristically has a large, squarish head ⅓ the length of its body; the blowhole is slightly to the left hand side; skin usually wrinkled; and no teeth on the upper jaw.
| Genus Physeter - 1 species | ||||||
| Common name | Scientific name | Status | Population | Distribution | Size | Picture |
|---|---|---|---|---|---|---|
| Sperm Whale | Physeter macrocephalus Linnaeus, 1758 |
Vulnerable (VU) | 200,000-2,000,000[24] |  |
 25-50 tonnes |
 |
[edit] Family Kogiidae: Dwarf and Pygmy Sperm Whales
- See also: Kogiidae
The Dwarf and Pygmy Sperm Whales resemble Sperm Whales, but are far smaller. They are dark grey, dorsally, while ventrally they are lighter. They have blunt, squarish heads with a narrow underslung jaw; the flippers are set far forward, close to the head and the dorsal fin is set far back down the body.
| Genus Kogia - 2 species | ||||||
| Common name | Scientific name | Status | Population | Distribution | Size | Picture |
|---|---|---|---|---|---|---|
| Dwarf Sperm Whale | Kogia sima Owen, 1866 |
Least Concern (LR/lc) | Unknown[25] |  |
 250 kilograms |
|
| Pygmy Sperm Whale | Kogia breviceps Blainville, 1838 |
Least Concern (LR/lc) | Unknown[26] |  |
 400 kilograms |
[edit] Family Ziphiidae: Beaked Whales
- See also: Ziphiidae
A beaked whale is any of at least 20 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 characterised 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.[1]
| Genus Ziphius - 1 species | ||||||
| Common name | Scientific name | Status | Population | Distribution | Size | Picture |
|---|---|---|---|---|---|---|
| Cuvier's Beaked Whale | Ziphius cavirostris G. Cuvier, 1823 |
Data deficient | Unknown[27] |  |
 2-3 tonnes |
|
| Genus Berardius - 2 species | ||||||
| Common name | Scientific name | Status | Population | Distribution | Size | Picture |
| Arnoux's Beaked Whale | Berardius arnuxii Duvernoy, 1851 |
Conservation Dependent (LR/cd) | Unknown[28] |  |
 8 tonnes |
|
| Baird's Beaked Whale | Berardius bairdii Stejneger, 1883 |
Conservation Dependent (LR/cd) | Unknown[29] |  |
 12 tonnes |
|
| Genus Tasmacetus - 1 species | ||||||
| Common name | Scientific name | Status | Population | Distribution | Size | Picture |
| Shepherd's Beaked Whale | Tasmacetus shepherdi Oliver, 1937 |
Data deficient | Unknown[30] |  |
 2-2.5 tonnes |
|
| Subfamily Hyperoodontidae - 3 genera, 17 species | ||||||
| Genus Indopacetus - 1 species | ||||||
| Common name | Scientific name | Status | Population | Distribution | Size | Picture |
| Longman's Beaked Whale | Indopacetus pacificus Longman, 1926 |
Data deficent | Unknown[31] |  |
||
| Genus Hyperoodon - 2 species | ||||||
| Common name | Scientific name | Status | Population | Distribution | Size | Picture |
| Northern Bottlenose Whale | Hyperoodon ampullatus Forster, 1770 |
Conservation Dependent (LR/cd) | 10,000[32] |  |
 7 tonnes |
|
| Southern Bottlenose Whale | Hyperoodon planifrons Flower, 1882 |
Conservation Dependent (LR/cd) | 500,000[33] |  |
 6 tonnes |
|
| Genus Mesoplodon Gervais, 1850 - 14 species | ||||||
| Common name | Scientific name | Status | Population | Distribution | Size | Picture |
| Hector's Beaked Whale | Mesoplodon hectori Gray, 1871 |
Data deficient | Unknown |  |
 1 tonne |
|
| True's Beaked Whale | Mesoplodon mirus True, 1913 |
Data deficient | Unknown |  |
 1.4 tonnes |
|
| Gervais' Beaked Whale | Mesoplodon europaeus Gervais, 1855 |
Data deficient | Unknown |  |
 1.2 tonnes |
|
| Sowerby's Beaked Whale | Mesoplodon bidens Sowerby, 1804 |
Data deficient | Unknown |  |
 1-1.3 tonnes |
 |
| Gray's Beaked Whale | Mesoplodon grayi von Haast, 1876 |
Data deficient | Unknown |  |
 1.5 tonnes |
|
| Pygmy Beaked Whale | Mesoplodon peruvianus Reyes, Mead, and Van Waerebeek, 1991 |
Data deficient | Unknown |  |
||
| Andrews' Beaked Whale | Mesoplodon bowdoini Gervais, 1850 |
Data deficient | Unknown |  |
 1 tonne |
|
| Bahamonde's Beaked Whale | Mesoplodon bahamondi Gray, 1874 |
Data deficient | Unknown | |||
| Hubbs' Beaked Whale | Mesoplodon carlhubbsi Sowerby, 1963 |
Data deficient | Unknown |  |
 1.4 tonnes |
|
| Ginkgo-toothed Beaked Whale | Mesoplodon ginkgodens Nishiwaki & Kamiya, 1958 |
Data deficient | Unknown |  |
 1.5 tonnes |
|
| Stejneger's Beaked Whale | Mesoplodon stejnegeri True, 1885 |
Data deficient | Unknown |  |
 1.5 tonnes |
|
| Layard's Beaked Whale | Mesoplodon layardii Gray, 1865 |
Data deficient | Unknown |  |
 2 tonnes |
|
| Blainville's Beaked Whale | Mesoplodon densirostris Blainville, 1817 |
Data deficient | Unknown |  |
 1 tonne |
|
| Perrin's Beaked Whale | Mesoplodon perrini Dalebout, Mead, Baker, Baker, & van Helding, 2002 |
Data deficient | Unknown |
[edit] Superfamily Platanistoidea: river dolphins
- See also: Platanistoidea
River dolphins are four species of dolphin which reside in freshwater rivers and estuaries. They are classed in the Platanistoidea superfamily of cetaceans. Three species live in fresh water rivers. The fourth 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.
[edit] Family Iniidae: Boto
The Iniidae family of river dolphins is monotypic, containing only one genus and one species: the Boto. Although in the past two species were thought to exist is now accepted that just three subspecies of the Boto exist:[34]
- I.g. geoffrensis - Amazon basin population (excluding Madeira river drainage area, above the Teotonio Rapids in Bolivia)
- I.g. boliviensis - Amazon basin population in the Madeira drainage area
- I.g. humboldtiana - Orinoco basin population
| Genus Inia - 1 species | ||||||
| Common name | Scientific name | Status | Population | Distribution | Size | Picture |
|---|---|---|---|---|---|---|
| Boto (Amazon River Dolphin) | Inia geoffrensis Blainville, 1817 |
Vulnerable (VU) | Unknown |  |
 150 kilograms |
 |
[edit] Family Lipotidae: Baiji
The Lipotidae family is another monotypic taxon, containing only the Baiji. Fossil records suggest that the dolphin first appeared 25 million years ago and migrated from the Pacific Ocean to the Yangtze River 20 million years ago.[35] The species was declared functionally extinct in 2006 after an expedition to record population numbers.
| Genus Lipotes - 1 species | ||||||
| Common name | Scientific name | Status | Population | Distribution | Size | Picture |
|---|---|---|---|---|---|---|
| Baiji (Chinese River Dolphin) | Lipotes vexillifer Miller, 1918 |
Critically Endangered (CR) Possibly extinct | 13[36] |  |
 130 kilograms |
[edit] Family Platanistidae: Ganges and Indus River Dolphin
The Platanistidae was originally thought to hold only one species (Ganges and Indus 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.[37] In 1998 the results of these studies were questioned and the classification reverted to the pre-1970 consensus. Thus, at present, there are two subpecies recognized in the genus Platanista, Platanista gangetica minor (the Indus dolphin) and Platanista gangetica gangetica (the Ganges River dolphin).[38]
| Genus Platanista - 1 species | ||||||
| Common name | Scientific name | Status | Population | Distribution | Size | Picture |
|---|---|---|---|---|---|---|
| Ganges and Indus River Dolphin | Platanista gangetica Roxburgh, 1801 |
Endangered (EN) | 1,100[39] |  |
 200 kilograms |
[edit] Family Pontoporiidae: La Plata River Dolphin
The La Plata River Dolphin is the only species of the Pontoporiidae family and of the Pontoporia genus.
| Genus Pontoporia - 1 species | ||||||
| Common name | Scientific name | Status | Population | Distribution | Size | Picture |
|---|---|---|---|---|---|---|
| La Plata Dolphin | Pontoporia blainvillei Gervais & d'Orbigny, 1844 |
Data deficient | 4,000-4,500 |  |
 50 kilograms |
[edit] Notes and references
- ^ a b c d e f g Martin, Dr. Anthony R. (1991). Whales and Dolphins. London: Salamander Books.
- ^ The total population is unknown but numbers in the hundreds of thousands.
- ^ The total population is unknown but numbers in the hundreds of thousands.
- ^ Estimates of various stocks throughout the North Atlantic give an overall value into the high tens or low hundreds of thousands.
- ^ Total population unknown but thought to be locally common - it is the most common dolphin found around the Falkland Islands
- ^ Varying population estimates for areas around California and the North Pacific give a total of up to 400,000
- ^ Surveys suggest that this is the most common dolphin off of Chilean waters.
- ^ 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.
- ^ 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.
- ^ The only population estimate is of 38,900 individuals in the eastern tropical Pacific Ocean
- ^ 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.
- ^ 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.
- ^ 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.
- ^ Total population not known. There are estimated to be in excess of 200,000 in the Southern Ocean. The North Atlantic population is not known.
- ^ 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.
- ^ 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.
- ^ There are not enough data to place finless porpoises on the endangered species list, except in China, where they are endangered. Their propensity for staying close to shore places them in great danger from fishing
- ^ 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.
- ^ Several surveys have been taken although large gaps of data is missing so an overall value cannot be achieved. In the Eastern Pacific Ocean: Central California 4,120; Northern California 9,250; Oregon and Washington 26,175. In the Atlantic Ocean: Gulf of Maine 67,500; Skagerrak and Belt Seas 36,046; North Sea 279,367; Ireland and western UK 36,280.
- ^ 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.
- ^ 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.
- ^ There are no quantitative data on abundance.
- ^ The most recent estimate for the North Pacific and Bering Sea is 1,186,000.
- ^ 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.
- ^ No global population estimates have been made. One survey estimated a population of about 11,000 in the eastern Pacific.
- ^ No global population estimates have been made. One survey estimated a population of about 11,000 in the eastern Pacific.
- ^ Because of the difficulty of identifying the species the total global population is unknown.
- ^ Arnoux's beaked whales seem to be relatively abundant in Cook Strait during summer
- ^ Virtually nothing is known about the abundance of Baird's beaked whales, except that they are not rare as was formerly thought
- ^ Nothing is known about the relative abundance of this species or its population composition.
- ^ A 2002 survey estimates that there are 766 animals around Hawaii. No other population estimates exist for other locales.
- ^ Total population is unknown but likely to be of the order of 10,000.
- ^ There is thought to be a global population in excess of 500,000.
- ^ Rice, Dale W. (1998). Marine mammals of the world: systematics and distribution. Society of Marine Mammalogy Special Publication Number 4. 231 pp.
- ^ Wang, Yongchen (2007-01-10). Farewell to the Baiji. China Dialogue. Retrieved on 2007-05-29.
- ^ 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.
- ^ 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.
- ^ Rice, DW (1998). Marine mammals of the world: Systematics and distribution. Society for Marine Mammalogy. ISBN 978-1891276033.
- ^ Estimates give values of 1,100 Indus River Dolphins and maybe as few as 20 Ganges River Dolphins.
- General references
- Rice, Dale W. (1998). "Marine mammals of the world: systematics and distribution". Society of Marine Mammalogy Special Publication Number 4: 231pp.
- Mead, James G. and Robert L. Brownell, Jr (November 16, 2005). in Wilson, D. E., and Reeder, D. M. (eds): Mammal Species of the World, 3rd edition, Johns Hopkins University Press, 723-743. ISBN 0-801-88221-4.
- Red List of Threatened Species. IUCN. Retrieved on 2006-11-09.
[edit] See also
[edit] External links
- ARKive - images and movies of Whales, Dolphins and Porpoises
- American Cetacean Society
- CMS Small Cetaceans
- IUCN Redlist
