Portal:Cetaceans

The Cetaceans Portal

A Sperm Whale fluke
A Sperm Whale fluke

Cetaceans (/sɪˈteɪʃə/) are marine mammals belonging to the infraorder Cetacea, a secondarily aquatic clade under the order Artiodactyla that include whales, dolphins, porpoises and extinct groups such as Basilosaurus. Most cetaceans live in marine environments, particularly the pelagic zone, but some reside solely in brackish or fresh water. Having a cosmopolitan distribution, they can be found in some rivers and all of Earth's oceans. Many species migrate seasonally over vast ranges for food advantages.

Key characteristics of cetaceans are their fully aquatic life cycle, streamlined, fish-like body shape, the need to periodically surface and breath air, and exclusively carnivorous diet. All extant cetaceans are capable of echolocation.

As nektonic animals, cetaceans propel themselves through the water with powerful up-and-down movements of their tails, which have evolved into in a horizontal paddle-like fluke. Their hindlimbs have disappeared with only some vestigial skeleton of the pelvis and femurs, and their forelimbs have evolved into flippers which they use to paddle and steer. Some fast-swimming groups, most notably the smaller dolphins and porpoises, have a dorsal fin to facilitate directional stability. Cetaceans also have large brains and have high intelligence, complex social behaviour, and song-like communication. Some cetaceans have large bodies, such as the blue whale, which reaches a maximum confirmed length of 29.9 meters (98 feet) and a weight of 173 tonnes (190 short tons), making it the largest animal known to have existed.

There are approximately 90 living cetacean species split into two parvorders: Odontoceti or toothed whales, which contains 75 species including porpoises, dolphins, the beaked whales and other predatory whales like the beluga and sperm whale, who prey upon fish, cephalopods and other marine mammals such as pinnipeds; and Mysticeti or baleen whales, which contains 15 species of large whales including the blue whale, humpback whale and bowhead whale among others, who are mostly filter-feeding planktivores (or sometimes bottom-feeding crustacivores or molluscivores, as in the case of the gray whale) using oral bristle plates known as baleen to sieve out and feed on large swarms of small invertebrates, usually crustaceans such as krill. Despite their highly modified bodies and carnivorous lifestyle, genetic and fossil evidence places cetaceans within the terrestrial even-toed ungulates, most closely related to the hippopotamids. (Full article...)

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  • Image 1 The narwhal (Monodon monoceros) is a species of toothed whale native to the Arctic. It is the only member of the genus Monodon and one of two living representatives of the family Monodontidae. The narwhal is a stocky cetacean with a relatively blunt snout, a large melon, and a shallow ridge in place of a dorsal fin. Males of this species have a spiralled tusk that is 1.5–3.0 m (4.9–9.8 ft) long, which is a protruding left canine thought to function as a weapon, a tool for feeding, in attracting mates or sensing water salinity. Specially adapted slow-twitch muscles, along with the jointed neck vertebrae and shallow dorsal ridge allow for easy movement through the Arctic environment, where the narwhal spends extended periods at great depths. The narwhal's geographic range overlaps with that of the similarly built and closely related beluga whale, and the animals are known to interbreed. Narwhals inhabit the Arctic waters of Canada, Greenland and Russia. Every year, they migrate to ice-free summering grounds, usually in shallow waters, and often return to the same sites in subsequent years. Their diet mainly consists of polar and Arctic cod, Greenland halibut, cuttlefish, shrimp, and armhook squid. Diving to depths of up to 2,370 m (7,780 ft), the narwhal is among the deepest-diving cetaceans. The animals typically travel in groups of three to eight, with aggregations of up to 1,000 occurring in the summer months. Narwhals mate among the offshore pack ice from March to May, and the young are born between July and August of the following year. When communicating amongst themselves, narwhals use a variety of clicks, whistles and knocks. (Full article...)

    The narwhal (Monodon monoceros) is a species of toothed whale native to the Arctic. It is the only member of the genus Monodon and one of two living representatives of the family Monodontidae. The narwhal is a stocky cetacean with a relatively blunt snout, a large melon, and a shallow ridge in place of a dorsal fin. Males of this species have a spiralled tusk that is 1.5–3.0 m (4.9–9.8 ft) long, which is a protruding left canine thought to function as a weapon, a tool for feeding, in attracting mates or sensing water salinity. Specially adapted slow-twitch muscles, along with the jointed neck vertebrae and shallow dorsal ridge allow for easy movement through the Arctic environment, where the narwhal spends extended periods at great depths. The narwhal's geographic range overlaps with that of the similarly built and closely related beluga whale, and the animals are known to interbreed.

    Narwhals inhabit the Arctic waters of Canada, Greenland and Russia. Every year, they migrate to ice-free summering grounds, usually in shallow waters, and often return to the same sites in subsequent years. Their diet mainly consists of polar and Arctic cod, Greenland halibut, cuttlefish, shrimp, and armhook squid. Diving to depths of up to 2,370 m (7,780 ft), the narwhal is among the deepest-diving cetaceans. The animals typically travel in groups of three to eight, with aggregations of up to 1,000 occurring in the summer months. Narwhals mate among the offshore pack ice from March to May, and the young are born between July and August of the following year. When communicating amongst themselves, narwhals use a variety of clicks, whistles and knocks. (Full article...)
  • Image 2 Cryptolepas rhachianecti Whale barnacles are species of acorn barnacle that belong to the family Coronulidae. They typically attach to baleen whales, and sometimes settle on toothed whales. The whale barnacles diverged from the turtle barnacles about three million years ago. Whale barnacles passively filter food, using tentacle-like cirri, as the host swims through the water. The arrangement is generally considered commensal as it is done at no cost or benefit to the host. However, some whales may make use of the barnacles as protective armor or for inflicting more damage while fighting, which would make the relationship mutualistic where both parties benefit; alternatively, some species may just increase the drag that the host experiences while swimming, making the barnacles parasites. (Full article...)

    Cryptolepas rhachianecti

    Whale barnacles are species of acorn barnacle that belong to the family Coronulidae. They typically attach to baleen whales, and sometimes settle on toothed whales. The whale barnacles diverged from the turtle barnacles about three million years ago.

    Whale barnacles passively filter food, using tentacle-like cirri, as the host swims through the water. The arrangement is generally considered commensal as it is done at no cost or benefit to the host. However, some whales may make use of the barnacles as protective armor or for inflicting more damage while fighting, which would make the relationship mutualistic where both parties benefit; alternatively, some species may just increase the drag that the host experiences while swimming, making the barnacles parasites. (Full article...)
  • Image 3 The false killer whale (Pseudorca crassidens) is a species of oceanic dolphin that is the only extant representative of the genus Pseudorca. It is found in oceans worldwide but mainly in tropical regions. It was first described in 1846 as a species of porpoise based on a skull, which was revised when the first carcasses were observed in 1861. The name "false killer whale" comes from having a skull similar to the orca or killer whale (Orcinus orca). The false killer whale reaches a maximum length of 6 m (20 ft), though size can vary around the world. It is highly sociable, known to form pods of up to 50 members, and can also form pods with other dolphin species, such as the common bottlenose dolphin (Tursiops truncatus). It can form close bonds with other species, as well as have sexual interactions with them. But the false killer whale has also been known to eat other dolphins, though it typically eats squid and fish. It is a deep-diver; maximum known depth is 927.5 m (3,043 ft); maximum speed is around 29 km/h (18 mph). (Full article...)

    The false killer whale (Pseudorca crassidens) is a species of oceanic dolphin that is the only extant representative of the genus Pseudorca. It is found in oceans worldwide but mainly in tropical regions. It was first described in 1846 as a species of porpoise based on a skull, which was revised when the first carcasses were observed in 1861. The name "false killer whale" comes from having a skull similar to the orca or killer whale (Orcinus orca).

    The false killer whale reaches a maximum length of 6 m (20 ft), though size can vary around the world. It is highly sociable, known to form pods of up to 50 members, and can also form pods with other dolphin species, such as the common bottlenose dolphin (Tursiops truncatus). It can form close bonds with other species, as well as have sexual interactions with them. But the false killer whale has also been known to eat other dolphins, though it typically eats squid and fish. It is a deep-diver; maximum known depth is 927.5 m (3,043 ft); maximum speed is around 29 km/h (18 mph). (Full article...)
  • Image 4 Whaling in the Faroe Islands, or grindadráp (from the Faroese terms grindhvalur, meaning pilot whale, and dráp, meaning killing), is a type of drive hunting that involves herding various species of whales and dolphins, but primarily pilot whales, into shallow bays to be beached, killed, and butchered. Each year, an average of around 700 long-finned pilot whales are caught, alongside varying numbers of Atlantic white-sided dolphins. The practice dates back to the 9th century, and many Faroe Islanders consider eating whales to be an important part of their history. Since 1948, the hunt has been regulated by the Faroese authorities, required its participants to be trained, involved modern boats and communications, and been supervised by police. (Full article...)

    Whaling in the Faroe Islands, or grindadráp (from the Faroese terms grindhvalur, meaning pilot whale, and dráp, meaning killing), is a type of drive hunting that involves herding various species of whales and dolphins, but primarily pilot whales, into shallow bays to be beached, killed, and butchered. Each year, an average of around 700 long-finned pilot whales are caught, alongside varying numbers of Atlantic white-sided dolphins.

    The practice dates back to the 9th century, and many Faroe Islanders consider eating whales to be an important part of their history. Since 1948, the hunt has been regulated by the Faroese authorities, required its participants to be trained, involved modern boats and communications, and been supervised by police. (Full article...)
  • Image 5 Cetacea is an infraorder that comprises the 94 species of whales, dolphins, and porpoises. It is divided into toothed whales (Odontoceti) and baleen whales (Mysticeti), which diverged from each other in the Eocene some 50 million years ago (mya). Cetaceans are descended from land-dwelling hoofed mammals, and the now extinct archaeocetes represent the several transitional phases from terrestrial to completely aquatic. Historically, cetaceans were thought to have descended from the wolf-like mesonychians, but cladistic analyses confirm their placement with even-toed ungulates in the order Cetartiodactyla. Whale populations were drastically reduced in the 20th century from intensive whaling, which led to a moratorium on hunting by the International Whaling Commission in 1982. Smaller cetaceans are at risk of accidentally getting caught by fishing vessels using, namely, seine fishing, drift netting, or gill netting operations. (Full article...)
    Cetacea is an infraorder that comprises the 94 species of whales, dolphins, and porpoises. It is divided into toothed whales (Odontoceti) and baleen whales (Mysticeti), which diverged from each other in the Eocene some 50 million years ago (mya). Cetaceans are descended from land-dwelling hoofed mammals, and the now extinct archaeocetes represent the several transitional phases from terrestrial to completely aquatic. Historically, cetaceans were thought to have descended from the wolf-like mesonychians, but cladistic analyses confirm their placement with even-toed ungulates in the order Cetartiodactyla.

    Whale populations were drastically reduced in the 20th century from intensive whaling, which led to a moratorium on hunting by the International Whaling Commission in 1982. Smaller cetaceans are at risk of accidentally getting caught by fishing vessels using, namely, seine fishing, drift netting, or gill netting operations. (Full article...)
  • Image 6 Pilot whales are cetaceans belonging to the genus Globicephala. The two extant species are the long-finned pilot whale (G. melas) and the short-finned pilot whale (G. macrorhynchus). The two are not readily distinguishable at sea, and analysis of the skulls is the best way to distinguish between the species. Between the two species, they range nearly worldwide, with long-finned pilot whales living in colder waters and short-finned pilot whales living in tropical and subtropical waters. Pilot whales are among the largest of the oceanic dolphins, exceeded in size only by the orca. They and other large members of the dolphin family are also known as blackfish. Pilot whales feed primarily on squid, but will also hunt large demersal fish such as cod and turbot. They are highly social and may remain with their birth pod throughout their lifetime. Short-finned pilot whales are one of the few non-primate mammal species in which females go through menopause, and postreproductive females continue to contribute to their pod. Pilot whales are notorious for stranding themselves on beaches, but the reason behind this is not fully understood. Marine biologists have shed some light on the matter, suggesting that it is due to the mammals inner ear (their principal navigational sonar) being damaged from noise pollution in the ocean, such as from cargo ships or military exercises. The conservation status of short-finned and long-finned pilot whales has been determined to be least concern. (Full article...)

    Pilot whales are cetaceans belonging to the genus Globicephala. The two extant species are the long-finned pilot whale (G. melas) and the short-finned pilot whale (G. macrorhynchus). The two are not readily distinguishable at sea, and analysis of the skulls is the best way to distinguish between the species. Between the two species, they range nearly worldwide, with long-finned pilot whales living in colder waters and short-finned pilot whales living in tropical and subtropical waters. Pilot whales are among the largest of the oceanic dolphins, exceeded in size only by the orca. They and other large members of the dolphin family are also known as blackfish.

    Pilot whales feed primarily on squid, but will also hunt large demersal fish such as cod and turbot. They are highly social and may remain with their birth pod throughout their lifetime. Short-finned pilot whales are one of the few non-primate mammal species in which females go through menopause, and postreproductive females continue to contribute to their pod. Pilot whales are notorious for stranding themselves on beaches, but the reason behind this is not fully understood. Marine biologists have shed some light on the matter, suggesting that it is due to the mammals inner ear (their principal navigational sonar) being damaged from noise pollution in the ocean, such as from cargo ships or military exercises. The conservation status of short-finned and long-finned pilot whales has been determined to be least concern. (Full article...)
  • Image 7 Sei whale mother and calf The sei whale (/seɪ/ SAY, Norwegian: [sæɪ]; Balaenoptera borealis) is a baleen whale. It is one of ten rorqual species, and the third-largest member after the blue and fin whales. It can grow to 19.5 m (64 ft) in length and weigh as much as 28 t (28 long tons; 31 short tons). Two subspecies are recognized: B. b. borealis and B. b. schlegelii. The whale's ventral surface has sporadic markings ranging from light grey to white, and its body is usually dark steel grey in colour. It is among the fastest of all cetaceans, and can reach speeds of up to 50–55 km/h (31–34 mph) over short distances.  It inhabits most oceans and adjoining seas, and prefers deep offshore waters. It avoids polar and tropical waters and semi-enclosed bodies of water. The sei whale migrates annually from cool, subpolar waters in summer to temperate, subtropical waters in winter with a lifespan of 70 years. It is a filter feeder, with its diet consisting primarily of copepods, krill, and other zooplankton. It is typically solitary or can be found in groups numbering half a dozen. During the breeding period, a mating pair will remain together. Sei whale vocalizations usually last approximately half a second, and occurs at 240–625 hertz. (Full article...)

    Sei whale mother and calf

    The sei whale (/seɪ/ SAY, Norwegian: [sæɪ]; Balaenoptera borealis) is a baleen whale. It is one of ten rorqual species, and the third-largest member after the blue and fin whales. It can grow to 19.5 m (64 ft) in length and weigh as much as 28 t (28 long tons; 31 short tons). Two subspecies are recognized: B. b. borealis and B. b. schlegelii. The whale's ventral surface has sporadic markings ranging from light grey to white, and its body is usually dark steel grey in colour. It is among the fastest of all cetaceans, and can reach speeds of up to 50–55 km/h (31–34 mph) over short distances. 

    It inhabits most oceans and adjoining seas, and prefers deep offshore waters. It avoids polar and tropical waters and semi-enclosed bodies of water. The sei whale migrates annually from cool, subpolar waters in summer to temperate, subtropical waters in winter with a lifespan of 70 years. It is a filter feeder, with its diet consisting primarily of copepods, krill, and other zooplankton. It is typically solitary or can be found in groups numbering half a dozen. During the breeding period, a mating pair will remain together. Sei whale vocalizations usually last approximately half a second, and occurs at 240–625 hertz. (Full article...)
  • Image 8 Skeleton at the Museo Capellini di Bologna Orcinus citoniensis is an extinct species of orca identified in the Late Pliocene of Italy and the Early Pleistocene of England. It was smaller than the modern killer whale (O. orca), 4 m (13 ft) versus 7 to 10 m (23 to 33 ft), and had around 8 more teeth in its jaw. It may have resembled the modern killer whale in appearance, and could represent a transitional species between the modern killer whale and other dolphins. O. citoniensis could have hunted fish and squid in pods, and coexisted with other large predators of the time such as the orcinine Hemisyntrachelus and the extinct shark Otodus megalodon. (Full article...)

    Skeleton at the Museo Capellini di Bologna

    Orcinus citoniensis is an extinct species of orca identified in the Late Pliocene of Italy and the Early Pleistocene of England. It was smaller than the modern killer whale (O. orca), 4 m (13 ft) versus 7 to 10 m (23 to 33 ft), and had around 8 more teeth in its jaw. It may have resembled the modern killer whale in appearance, and could represent a transitional species between the modern killer whale and other dolphins. O. citoniensis could have hunted fish and squid in pods, and coexisted with other large predators of the time such as the orcinine Hemisyntrachelus and the extinct shark Otodus megalodon. (Full article...)
  • Image 9 River dolphins are a polyphyletic group of fully aquatic mammals that reside exclusively in freshwater or brackish water. They are an informal grouping of dolphins, which itself is a paraphyletic group within the infraorder Cetacea. Extant river dolphins are placed in two superfamilies, Platanistoidea and Inioidea. They comprise the families Platanistidae (the South Asian dolphins), the possibly extinct Lipotidae (Yangtze River dolphin), Iniidae (the Amazonian dolphins) and Pontoporiidae. There are five extant species of river dolphins. River dolphins, alongside other cetaceans, belong to the clade Artiodactyla, with even-toed ungulates, and their closest living relatives the hippopotamuses, from which they diverged about 40 million years ago. Specific types of dolphins can be pink. River dolphins are relatively small compared to other dolphins, having evolved to survive in warm, shallow water and strong river currents. They range in size from the 5-foot (1.5 m) long South Asian river dolphin to the 8-foot (2.4 m) and 220-pound (100 kg) Amazon river dolphin. Several species exhibit sexual dimorphism, in that the females are larger than the males. They have streamlined bodies and two limbs that are modified into flippers. River dolphins use their conical-shaped teeth and long beaks to capture fast-moving prey in murky water. They have well-developed hearing that is adapted for both air and water; they do not really rely on vision since their eyes are very small and the water they swim in is usually very muddy. Instead, they tend to rely on echolocation when hunting and navigating. These species are well-adapted to living in warm, shallow waters, and, unlike other cetaceans, have little to no blubber. (Full article...)
    River dolphins are a polyphyletic group of fully aquatic mammals that reside exclusively in freshwater or brackish water. They are an informal grouping of dolphins, which itself is a paraphyletic group within the infraorder Cetacea. Extant river dolphins are placed in two superfamilies, Platanistoidea and Inioidea. They comprise the families Platanistidae (the South Asian dolphins), the possibly extinct Lipotidae (Yangtze River dolphin), Iniidae (the Amazonian dolphins) and Pontoporiidae. There are five extant species of river dolphins. River dolphins, alongside other cetaceans, belong to the clade Artiodactyla, with even-toed ungulates, and their closest living relatives the hippopotamuses, from which they diverged about 40 million years ago. Specific types of dolphins can be pink.

    River dolphins are relatively small compared to other dolphins, having evolved to survive in warm, shallow water and strong river currents. They range in size from the 5-foot (1.5 m) long South Asian river dolphin to the 8-foot (2.4 m) and 220-pound (100 kg) Amazon river dolphin. Several species exhibit sexual dimorphism, in that the females are larger than the males. They have streamlined bodies and two limbs that are modified into flippers. River dolphins use their conical-shaped teeth and long beaks to capture fast-moving prey in murky water. They have well-developed hearing that is adapted for both air and water; they do not really rely on vision since their eyes are very small and the water they swim in is usually very muddy. Instead, they tend to rely on echolocation when hunting and navigating. These species are well-adapted to living in warm, shallow waters, and, unlike other cetaceans, have little to no blubber. (Full article...)
  • Image 10 Restored skeleton Brygmophyseter, known as the biting sperm whale, is an extinct genus of toothed whale in the sperm whale family with one species, B. shigensis. When it was first described in 1994, the species was placed in the genus Scaldicetus based on tooth morphology, but this was later revised in 2006. A month later since the naming of Brygmophyseter, another study classified this species into the genus Naganocetus, which is considered to be a junior synonym. The only known specimen, a nearly complete skeleton, was dated to be around 16–15 million years old (middle Miocene). The Brygmophyseter holotype is thought to have been 6.5–7 meters (21–23 ft) long, and it probably had 11 or 12 teeth in the upper and lower jaws. Brygmophyseter is part of a group of macroraptorial sperm whales (often shortened to "raptorial") which tended to be apex predators using their large teeth to catch struggling prey such as whales. It had a spermaceti organ which was probably used for biosonar like in the modern sperm whale. The whale has made an appearance on The History Channel's TV series Jurassic Fight Club. (Full article...)

    Restored skeleton

    Brygmophyseter, known as the biting sperm whale, is an extinct genus of toothed whale in the sperm whale family with one species, B. shigensis. When it was first described in 1994, the species was placed in the genus Scaldicetus based on tooth morphology, but this was later revised in 2006. A month later since the naming of Brygmophyseter, another study classified this species into the genus Naganocetus, which is considered to be a junior synonym. The only known specimen, a nearly complete skeleton, was dated to be around 16–15 million years old (middle Miocene). The Brygmophyseter holotype is thought to have been 6.5–7 meters (21–23 ft) long, and it probably had 11 or 12 teeth in the upper and lower jaws. Brygmophyseter is part of a group of macroraptorial sperm whales (often shortened to "raptorial") which tended to be apex predators using their large teeth to catch struggling prey such as whales. It had a spermaceti organ which was probably used for biosonar like in the modern sperm whale. The whale has made an appearance on The History Channel's TV series Jurassic Fight Club. (Full article...)
  • Image 11 The dusky dolphin (Aethalodelphis obscurus) is a small oceanic dolphin found in coastal waters of the Southern Hemisphere. It is most closely related to the Pacific white-sided dolphin. The dolphin's range is patchy, major populations occurring around South America, southwestern Africa, New Zealand, and several oceanic islands, with some sightings around southern Australia. It has a somewhat stocky body with a short beak and a curved dorsal fin and flippers. Like its closest relative, the dusky dolphin has a multi-coloured pigmentation of black, grey, and white. The species prefers cool currents and inshore waters. It lives in a fission–fusion society where groups change size based on social and environmental conditions. The dolphin feeds on several fish and squid species and has flexible hunting tactics, including daytime bait ball herding and nightime feeding in deep scattering layers. Mating is polygynandrous, and several males will chase after a single female, the fittest being able to catch her and reproduce. Females raise their young in nursery groups. The dusky dolphin is known for its acrobatics, displaying leaping behaviours which vary in complexity and may or may not create splashes. (Full article...)

    The dusky dolphin (Aethalodelphis obscurus) is a small oceanic dolphin found in coastal waters of the Southern Hemisphere. It is most closely related to the Pacific white-sided dolphin. The dolphin's range is patchy, major populations occurring around South America, southwestern Africa, New Zealand, and several oceanic islands, with some sightings around southern Australia. It has a somewhat stocky body with a short beak and a curved dorsal fin and flippers. Like its closest relative, the dusky dolphin has a multi-coloured pigmentation of black, grey, and white.

    The species prefers cool currents and inshore waters. It lives in a fission–fusion society where groups change size based on social and environmental conditions. The dolphin feeds on several fish and squid species and has flexible hunting tactics, including daytime bait ball herding and nightime feeding in deep scattering layers. Mating is polygynandrous, and several males will chase after a single female, the fittest being able to catch her and reproduce. Females raise their young in nursery groups. The dusky dolphin is known for its acrobatics, displaying leaping behaviours which vary in complexity and may or may not create splashes. (Full article...)
  • Image 12 A fin whale surfacing in waters around Greenland The fin whale (Balaenoptera physalus), also known as the finback whale or common rorqual, is a species of baleen whale and the second-longest cetacean after the blue whale. The biggest individual reportedly measured 26–27 m (85–89 ft) in length, with a maximum recorded weight of 65.5 to 120 tonnes (72.2 to 132.3 short tons; 64.5 to 118.1 long tons). The fin whale's body is long, slender and brownish-gray in color, with a paler underside to appear less conspicuous from below (countershading). At least two recognized subspecies exist, one in the North Atlantic and one across the Southern Hemisphere. It is found in all the major oceans, from polar to tropical waters, though it is absent only from waters close to the pack ice at the poles and relatively small areas of water away from the open ocean. The highest population density occurs in temperate and cool waters. Its prey mainly consists of smaller schooling fish, small squid, or crustaceans, including copepods and krill. Mating takes place in temperate, low-latitude seas during the winter. Fin whales are often observed in pods of 6–10 animals, with whom they communicate utilizing frequency-modulated sounds, ranging from 16 to 40 hertz. (Full article...)

    A fin whale surfacing in waters around Greenland

    The fin whale (Balaenoptera physalus), also known as the finback whale or common rorqual, is a species of baleen whale and the second-longest cetacean after the blue whale. The biggest individual reportedly measured 26–27 m (85–89 ft) in length, with a maximum recorded weight of 65.5 to 120 tonnes (72.2 to 132.3 short tons; 64.5 to 118.1 long tons). The fin whale's body is long, slender and brownish-gray in color, with a paler underside to appear less conspicuous from below (countershading).

    At least two recognized subspecies exist, one in the North Atlantic and one across the Southern Hemisphere. It is found in all the major oceans, from polar to tropical waters, though it is absent only from waters close to the pack ice at the poles and relatively small areas of water away from the open ocean. The highest population density occurs in temperate and cool waters. Its prey mainly consists of smaller schooling fish, small squid, or crustaceans, including copepods and krill. Mating takes place in temperate, low-latitude seas during the winter. Fin whales are often observed in pods of 6–10 animals, with whom they communicate utilizing frequency-modulated sounds, ranging from 16 to 40 hertz. (Full article...)
  • Image 13 Bottlenose dolphin surfing in the wake of a research boat The bottlenose dolphin is a toothed whale in the genus Tursiops. They are common, cosmopolitan members of the family Delphinidae, the family of oceanic dolphins. Molecular studies show the genus contains three species: the common bottlenose dolphin (Tursiops truncatus), the Indo-Pacific bottlenose dolphin (Tursiops aduncus), and Tamanend's bottlenose dolphin (Tursiops erebennus). Others, like the Burrunan dolphin (Tursiops (aduncus) australis), may be alternately considered their own species or be subspecies of T. aduncus. Bottlenose dolphins inhabit warm and temperate seas worldwide, being found everywhere except for the Arctic and Antarctic Circle regions. Their name derives from the Latin tursio (dolphin) and truncatus for the truncated teeth (the type specimen was old and had worn down teeth; this is not a typical characteristic of most members of the species). Numerous investigations of bottlenose dolphin intelligence have been conducted, examining mimicry, use of artificial language, object categorization, and self-recognition. They can use tools (sponging; using marine sponges to forage for food sources they normally could not access) and transmit cultural knowledge from generation to generation, and their considerable intelligence has driven interaction with humans. Bottlenose dolphins gained popularity from aquarium shows and television programs such as Flipper. They have also been trained by militaries to locate sea mines or detect and mark enemy divers. In some areas, they cooperate with local fishermen by driving fish into their nets and eating the fish that escape. Some encounters with humans are harmful to the dolphins: people hunt them for food, and dolphins are killed inadvertently as a bycatch of tuna fishing and by getting caught in crab traps. (Full article...)

    Bottlenose dolphin surfing in the wake of a research boat

    The bottlenose dolphin is a toothed whale in the genus Tursiops. They are common, cosmopolitan members of the family Delphinidae, the family of oceanic dolphins. Molecular studies show the genus contains three species: the common bottlenose dolphin (Tursiops truncatus), the Indo-Pacific bottlenose dolphin (Tursiops aduncus), and Tamanend's bottlenose dolphin (Tursiops erebennus). Others, like the Burrunan dolphin (Tursiops (aduncus) australis), may be alternately considered their own species or be subspecies of T. aduncus. Bottlenose dolphins inhabit warm and temperate seas worldwide, being found everywhere except for the Arctic and Antarctic Circle regions. Their name derives from the Latin tursio (dolphin) and truncatus for the truncated teeth (the type specimen was old and had worn down teeth; this is not a typical characteristic of most members of the species).

    Numerous investigations of bottlenose dolphin intelligence have been conducted, examining mimicry, use of artificial language, object categorization, and self-recognition. They can use tools (sponging; using marine sponges to forage for food sources they normally could not access) and transmit cultural knowledge from generation to generation, and their considerable intelligence has driven interaction with humans. Bottlenose dolphins gained popularity from aquarium shows and television programs such as Flipper. They have also been trained by militaries to locate sea mines or detect and mark enemy divers. In some areas, they cooperate with local fishermen by driving fish into their nets and eating the fish that escape. Some encounters with humans are harmful to the dolphins: people hunt them for food, and dolphins are killed inadvertently as a bycatch of tuna fishing and by getting caught in crab traps. (Full article...)
  • Image 14 Granny (born c. 1936-1951 approx, died c. 2016), also known as J2, was a female orca of the J pod of southern resident orcas notable for her long life. Early estimates placed her birth in 1911, putting her at 105 years old at the time of her death. However, this estimate was later theorized to have been based on mistaken information and more recent studies put her at 65–80 years old. If she was 105, she would have been the oldest known orca at the time of her death. Granny lived in the northeast Pacific Ocean and coastal bays of Washington state and British Columbia. She was last seen on October 12, 2016, and was considered deceased by The Center for Whale Research in January 2017. (Full article...)

    Granny (born c. 1936-1951 approx, died c. 2016), also known as J2, was a female orca of the J pod of southern resident orcas notable for her long life. Early estimates placed her birth in 1911, putting her at 105 years old at the time of her death. However, this estimate was later theorized to have been based on mistaken information and more recent studies put her at 65–80 years old. If she was 105, she would have been the oldest known orca at the time of her death. Granny lived in the northeast Pacific Ocean and coastal bays of Washington state and British Columbia. She was last seen on October 12, 2016, and was considered deceased by The Center for Whale Research in January 2017. (Full article...)
  • Image 15 Clockwise from top left: humpback whale, gray whale, North Atlantic right whale, and common minke whale Baleen whales (/bəˈliːn/), also known as whalebone whales, are marine mammals of the parvorder Mysticeti in the infraorder Cetacea (whales, dolphins and porpoises), which use baleen plates (or "whalebone") in their mouths to sieve plankton from the water. Mysticeti comprises the families Balaenidae (right and bowhead whales), Balaenopteridae (rorquals), Eschrichtiidae (the gray whale) and Cetotheriidae (the pygmy right whale). There are 16 species of baleen whales. While cetaceans were historically thought to have descended from mesonychians, molecular evidence instead supports them as a clade of even-toed ungulates (Artiodactyla). Baleen whales split from toothed whales (Odontoceti) around 34 million years ago. Baleen whales range in size from the 6 m (20 ft) and 3,000 kg (6,600 lb) pygmy right whale to the 31 m (102 ft) and 190 t (210 short tons) blue whale, the largest known animal to have ever existed. They are sexually dimorphic. Baleen whales can have streamlined or large bodies, depending on the feeding behavior, and two limbs that are modified into flippers. The fin whale is the fastest baleen whale, recorded swimming at 10 m/s (36 km/h; 22 mph). Baleen whales use their baleen plates to filter out food from the water by either lunge-feeding or skim-feeding. Baleen whales have fused neck vertebrae, and are unable to turn their heads at all. Baleen whales have two blowholes. Some species are well adapted for diving to great depths. They have a layer of fat, or blubber, under the skin to keep warm in the cold water. (Full article...)

    Clockwise from top left: humpback whale, gray whale, North Atlantic right whale, and common minke whale

    Baleen whales (/bəˈliːn/), also known as whalebone whales, are marine mammals of the parvorder Mysticeti in the infraorder Cetacea (whales, dolphins and porpoises), which use baleen plates (or "whalebone") in their mouths to sieve plankton from the water. Mysticeti comprises the families Balaenidae (right and bowhead whales), Balaenopteridae (rorquals), Eschrichtiidae (the gray whale) and Cetotheriidae (the pygmy right whale). There are 16 species of baleen whales. While cetaceans were historically thought to have descended from mesonychians, molecular evidence instead supports them as a clade of even-toed ungulates (Artiodactyla). Baleen whales split from toothed whales (Odontoceti) around 34 million years ago.

    Baleen whales range in size from the 6 m (20 ft) and 3,000 kg (6,600 lb) pygmy right whale to the 31 m (102 ft) and 190 t (210 short tons) blue whale, the largest known animal to have ever existed. They are sexually dimorphic. Baleen whales can have streamlined or large bodies, depending on the feeding behavior, and two limbs that are modified into flippers. The fin whale is the fastest baleen whale, recorded swimming at 10 m/s (36 km/h; 22 mph). Baleen whales use their baleen plates to filter out food from the water by either lunge-feeding or skim-feeding. Baleen whales have fused neck vertebrae, and are unable to turn their heads at all. Baleen whales have two blowholes. Some species are well adapted for diving to great depths. They have a layer of fat, or blubber, under the skin to keep warm in the cold water. (Full article...)

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Baleen from a mysticete cetacean
Baleen from a mysticete cetacean
Photo credit: David Monniaux

Baleen makes up baleen plates, which are arranged in two parallel rows that look like combs of thick hair; they are attached to the upper jaws of baleen whales. It is composed of keratin, which is the same substance that makes up human hair and nails. Whales use these combs for filter feeding. Whales are the only vertebrate group to use this method of feeding in great abundance (flamingos and crabeater seals use similar methods, but do not have baleen), and it has allowed them to grow to immense sizes. The Blue Whale, the largest animal ever to live, is a baleen whale.

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The Voyager Golden Record
The Voyager Golden Record
  • ...the songs of whales were sent into space aboard the Voyager spacecraft to represent sounds from Planet Earth.
  • ...the Beluga whale is also known as the Sea Canary on account of its high-pitched squeaks, squeals, and whistles.
  • ...Orcas are versatile predators with many populations actively hunting down whales such as the Grey Whale.
  • ...the Sperm Whale, at 18 metres long, is the largest toothed animal to have ever lived.
  • ...in spite of their enormous mass, baleen whales are capable of leaping completely out of the water, particularly the Humpback Whale.

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Cetacean articles

Whale species

Andrews' Beaked Whale • Balaenoptera omurai • Beluga • Blainville's Beaked Whale • Blue Whale • Bottlenose Whale • Bowhead Whale • Bryde's Whale • Cuvier's Beaked Whale • Dwarf Sperm Whale • Fin Whale • Gervais' Beaked Whale • Giant beaked whale • Ginkgo-toothed Beaked Whale • Gray Whale • Gray's Beaked Whale • Hector's Beaked Whale • Hubbs' Beaked Whale • Humpback Whale • Layard's Beaked Whale • Longman's Beaked Whale • Melon-headed Whale • Minke Whale • Narwhal • Perrin's Beaked Whale • Pygmy Beaked Whale • Pygmy Killer Whale • Pygmy Right Whale • Pygmy Sperm Whale • Right Whale • Sei Whale • Shepherd's Beaked Whale • Sowerby's Beaked Whale • Spade Toothed Whale • Sperm Whale • Stejneger's Beaked Whale • True's Beaked Whale

Dolphin species

Atlantic Spotted Dolphin • Atlantic White-sided Dolphin • Australian Snubfin Dolphin • Baiji • Boto • Chilean Dolphin • Clymene Dolphin • Commerson's Dolphin • Common Bottlenose Dolphin • Dusky Dolphin • False Killer Whale • Fraser's Dolphin • Ganges and Indus River Dolphin • Heaviside's Dolphin • Hector's Dolphin • Hourglass Dolphin • Humpback dolphin • Indo-Pacific Bottlenose Dolphin • Irrawaddy Dolphin • Killer Whale • La Plata Dolphin • Long-beaked Common Dolphin • Long-finned pilot whale • Pacific White-sided Dolphin • Pantropical Spotted Dolphin • Peale's Dolphin • Pygmy Killer Whale • Right whale dolphin • Risso's Dolphin • Rough-toothed Dolphin • Short-beaked Common Dolphin • Short-finned pilot whale • Spinner Dolphin • Striped Dolphin • Tucuxi • White-beaked Dolphin

Porpoise species

Burmeister's Porpoise • Dall's Porpoise • Finless Porpoise • Harbour Porpoise • Spectacled Porpoise • Vaquita

Other articles

Aboriginal whaling • Ambergris • Animal echolocation • Archaeoceti • Baleen • Baleen whale • Beached whale • Beaked Whale • Blowhole (biology) • Blubber • Bottlenose dolphin • Callosity • Cephalorhynchus • Cetacea • Cetacean intelligence • Cetology • Cetology of Moby-Dick • Common dolphin • Cumberland Sound Beluga • Dolphin • Dolphinarium • Dolphin drive hunting • Evolution of cetaceans • Exploding whale • Harpoon • History of whaling • Human–animal communication • Institute of Cetacean Research • International Whaling Commission • Lagenorhynchus • Melon (whale) • Mesoplodont Whale • Military dolphin • Moby-Dick • Mocha Dick • Monodontidae • Oceanic dolphin • Orcaella • Pilot Whale • Porpoise • River dolphin • River Thames Whale • Rorquals • Sperm whale family • Sperm whaling • Spermaceti • Stenella • Tay Whale • The Marine Mammal Center • Toothed Whale • U.S. Navy Marine Mammal Program • Whale • Whaling • Whale and Dolphin Conservation Society • Whale surfacing behaviour • Whale oil • Whale louse • Whale song • Whale watching • Wolphin

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