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133-463: See text Porpoises ( / ˈ p ɔː r p ə s ɪ z / ) are small dolphin -like cetaceans classified under the family Phocoenidae . Although similar in appearance to dolphins , they are more closely related to narwhals and belugas than to the true dolphins . There are eight extant species of porpoise, all among the smallest of the toothed whales . Porpoises are distinguished from dolphins by their flattened, spade-shaped teeth distinct from

266-530: A dolphinarium . Bottlenose dolphins are the most common species of dolphin kept in dolphinariums as they are relatively easy to train, have a long lifespan in captivity and have a friendly appearance. Hundreds if not thousands of bottlenose dolphins live in captivity across the world, though exact numbers are hard to determine. Other species kept in captivity are spotted dolphins , false killer whales and common dolphins , Commerson's dolphins , as well as rough-toothed dolphins , but all in much lower numbers than

399-447: A dorsal fin to prevent themselves from involuntarily spinning in the water. The oceanic dolphin ear is specifically adapted to the marine environment. In humans, the middle ear works as an impedance equalizer between the outside air's low impedance and the cochlear fluid's high impedance. In dolphins, and other marine mammals, there is no great difference between the outer and inner environments. Instead of sound passing through

532-401: A beached Vaquita showed remains of squid and grunts . Nothing is known about the diet of the spectacled porpoise. The tube in the head, through which this kind fish takes its breath and spitting water, located in front of the brain and ends outwardly in a simple hole, but inside it is divided by a downward bony septum, as if it were two nostrils; but underneath it opens up again in the mouth in

665-633: A dolphin in his coat of arms as King of Naples and Sicily. In contemporary days, a dolphin is still used in the coat of arms of many cities, as well as in the coat of arms of Anguilla and the coat of arms of Romania , and the coat of arms of Barbados has a dolphin supporter . Cardinal Angelo Amato , prefect of the Congregation of the Causes of Saints , a dolphin in his coat of arms, as well as Cardinal Godfried Danneels , former Metropolitan Archbishop of Mechelen-Brussels . Genus The composition of

798-421: A dolphin-friendly way. The earliest campaigns with "Dolphin safe" labels were initiated in the 1980s as a result of cooperation between marine activists and the major tuna companies, and involved decreasing incidental dolphin kills by up to 50% by changing the type of nets used to catch tuna. The dolphins are netted only while fishermen are in pursuit of smaller tuna. Albacore are not netted this way, making albacore

931-509: A few days after their rescue. Porpoises and other smaller cetaceans have traditionally been hunted in many areas, at least in Asia, Europe and North America, for their meat and blubber. A dominant hunting technique is drive hunting, where a pod of animals is driven together with boats and usually into a bay or onto a beach. Their escape is prevented by closing off the route to the ocean with other boats or nets. This type of fishery for harbour porpoises

1064-411: A few, like the orca, feed on large mammals, like seals. Male dolphins 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, and females bear all the responsibility for raising them. Mothers of some species fast and nurse their young for relatively long times. Dolphins produce a variety of vocalizations, usually in

1197-670: A flavor very similar to beef liver . Dolphin meat is high in mercury, and may pose a health danger to humans when consumed. The Faroe Islands population was exposed to methylmercury largely from contaminated pilot whale meat, which contained very high levels of about 2 mg methylmercury/kg. However, the Faroe Islands populations also eat significant amounts of fish. The study of about 900 Faroese children showed that prenatal exposure to methylmercury resulted in neuropsychological deficits at 7 years of age – World Health Organization There have been human health concerns associated with

1330-407: A genus is determined by taxonomists . The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that a newly defined genus should fulfill these three criteria to be descriptively useful: Moreover, genera should be composed of phylogenetic units of

1463-508: A good degree of eyesight. As well as this, the eyes of a porpoise are placed on the sides of its head, so their vision consists of two fields, rather than a binocular view like humans have. When porpoises surface, their lens and cornea correct the nearsightedness that results from the refraction of light; their eyes contain both rod and cone cells, meaning they can see in both dim and bright light. Porpoises do, however, lack short wavelength sensitive visual pigments in their cone cells indicating

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1596-486: A good sense of taste, as their taste buds are atrophied or missing altogether. However, some have preferences between different kinds of fish, indicating some sort of attachment to taste. Unlike most animals, porpoises are conscious breathers. All mammals sleep, but porpoises cannot afford to become unconscious for long because they may drown. While knowledge of sleep in wild cetaceans is limited, porpoises in captivity have been recorded to sleep with one side of their brain at

1729-643: A later homonym of a validly published name is a nomen illegitimum or nom. illeg. ; for a full list refer to the International Code of Nomenclature for algae, fungi, and plants and the work cited above by Hawksworth, 2010. In place of the "valid taxon" in zoology, the nearest equivalent in botany is " correct name " or "current name" which can, again, differ or change with alternative taxonomic treatments or new information that results in previously accepted genera being combined or split. Prokaryote and virus codes of nomenclature also exist which serve as

1862-621: A long time and redescribed as new by a range of subsequent workers, or if a range of genera previously considered separate taxa have subsequently been consolidated into one. For example, the World Register of Marine Species presently lists 8 genus-level synonyms for the sperm whale genus Physeter Linnaeus, 1758, and 13 for the bivalve genus Pecten O.F. Müller, 1776. Within the same kingdom, one generic name can apply to one genus only. However, many names have been assigned (usually unintentionally) to two or more different genera. For example,

1995-451: A more limited capacity for color vision than most mammals. Most dolphins have slightly flattened eyeballs, enlarged pupils (which shrink as they surface to prevent damage), slightly flattened corneas and a tapetum lucidum ; these adaptations allow for large amounts of light to pass through the eye and, therefore, a very clear image of the surrounding area. They also have glands on the eyelids and outer corneal layer that act as protection for

2128-514: A more limited capacity for colour vision than most mammals. Most porpoises have slightly flattened eyeballs, enlarged pupils (which shrink as they surface to prevent damage), slightly flattened corneas and a tapetum lucidum ; these adaptations allow for large amounts of light to pass through the eye and, therefore, they are able to form a very clear image of the surrounding area. The olfactory lobes are absent in porpoises, suggesting that they have no sense of smell. Porpoises are not thought to have

2261-403: A newborn calf's mouth does not allow it to obtain a seal around the nipple—instead of the calf sucking milk, the mother squirts milk into the calf's mouth. This milk contains high amounts of fat, which aids in the development of blubber; it contains so much fat that it has the consistency of toothpaste. The calves are weaned at about 11 months of age. Males play no part in rearing calves. The calf

2394-468: A range of tens to hundreds of square kilometres. Some pods have a loose social structure, with individuals frequently joining or leaving, but others seem to be more permanent, perhaps dominated by a male and a harem of females. Individuals communicate by sound, producing low-frequency whistles, and also produce high-frequency broadband clicks of 80–220 kHz, which are primarily used for echolocation . Gestation lasts from 10 to 18 months, and results in

2527-409: A reference for designating currently accepted genus names as opposed to others which may be either reduced to synonymy, or, in the case of prokaryotes, relegated to a status of "names without standing in prokaryotic nomenclature". An available (zoological) or validly published (botanical) name that has been historically applied to a genus but is not regarded as the accepted (current/valid) name for

2660-406: A signature whistle of an individual they have not encountered for over twenty years. Research done on signature whistle usage by other dolphin species is relatively limited. The research on other species done so far has yielded varied outcomes and inconclusive results. Oceanic dolphins frequently leap above the water surface, this being done for various reasons. When travelling, jumping can save

2793-404: A smaller number of squid and small crustaceans, but some species specialise in eating squid, or, in the case of the orca, also eat marine mammals and birds. All, however, are purely carnivorous . They typically have between 100 and 200 teeth, although a few species have considerably fewer. Delphinids travel in large pods, which may number a thousand individuals in some species. Each pod forages over

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2926-427: A taxon; however, the names published in suppressed works are made unavailable via the relevant Opinion dealing with the work in question. In botany, similar concepts exist but with different labels. The botanical equivalent of zoology's "available name" is a validly published name . An invalidly published name is a nomen invalidum or nom. inval. ; a rejected name is a nomen rejiciendum or nom. rej. ;

3059-424: A thick layer from the milk, which has a very high fat content. Porpoises have two flippers on the front and a tail fin. Their flippers contain four digits. Although porpoises do not possess fully developed hind limbs, they possess discrete rudimentary appendages, which may contain feet and digits. Porpoises are fast swimmers in comparison to seals, which typically cruise at 9–28 km/h (5–15 kn). The fusing of

3192-411: A time, so that they may swim, breathe consciously, and avoid both predators and social contact during their period of rest. Porpoises are fully aquatic creatures. Females deliver a single calf after a gestation period lasting about a year. Calving takes place entirely under water, with the foetus positioned for tail-first delivery to help prevent drowning. Females have mammary glands, but the shape of

3325-455: A total of c. 520,000 published names (including synonyms) as at end 2019, increasing at some 2,500 published generic names per year. "Official" registers of taxon names at all ranks, including genera, exist for a few groups only such as viruses and prokaryotes, while for others there are compendia with no "official" standing such as Index Fungorum for fungi, Index Nominum Algarum and AlgaeBase for algae, Index Nominum Genericorum and

3458-416: A void. –John Ray, 1671, the earliest description of cetacean airways In Aristotle 's time, the 4th century BCE, porpoises were regarded as fish due to their superficial similarity. Aristotle, however, could already see many physiological and anatomical similarities with the terrestrial vertebrates, such as blood (circulation), lungs, uterus and fin anatomy. His detailed descriptions were assimilated by

3591-412: A wide range of colors and patterns. Oceanic dolphins have a torpedo-shaped, muscular body with an inflexible neck, limbs modified into flippers, nonexistent external ear flaps, a large tail fin, and a bulbous head. A dolphin skull has small eye orbits, a long snout, but not as long as its river dolphin counterpart, and eyes placed on the sides of its head. Several species exhibit sexual dimorphism, with

3724-784: A zoo in Germany. At least 150 harbour porpoises have been kept worldwide, but only about 20 were actively caught for captivity. The captive history is best documented from Denmark where about 100 harbour porpoises have been kept, most in the 1960s and 1970s. All but two were incidental catches in fishing nets or strandings. Nearly half of these died within a month of diseases caught before they were captured or from damage sustained during capture. Up until 1984, none lived for more than 14 months. Attempts to rehabilitate seven rescued individuals in 1986 only resulted in three that could be released 6 months later. Very few have been brought into captivity later, but they have lived considerably longer. In recent decades,

3857-451: Is Dall's porpoise. Odontocetes possess teeth with cementum cells overlying dentine cells. Unlike human teeth, which are composed mostly of enamel on the portion of the tooth outside of the gum, whale teeth have cementum outside the gum. Porpoises have a three-chambered stomach, including a fore-stomach and fundic and pyloric chambers. Porpoises, like other odontocetes, possess only one blowhole. Breathing involves expelling stale air from

3990-506: Is a serious problem for marine mammals. Heavy metals and plastic waste are not biodegradable, and sometimes cetaceans consume these hazardous materials, mistaking them for food items. As a result, the animals are more susceptible to diseases and have fewer offspring. Harbour porpoises from the English Channel were found to have accumulated heavy metals. The military and geologists employ strong sonar and produce an increases in noise in

4123-618: Is best documented from the Danish straits , where it occurred until the end of the 19th century (it was banned in 1899), and again during the shortages in World War I and World War II . The Inuit in the Arctic hunt harbour porpoises by shooting and drive hunt for Dall's porpoise still takes place in Japan. The number of individuals taken each year is in the thousands, although a quota of around 17,000 per year

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4256-414: Is consumed. Atlantic porpoises are thought to follow the seasonal migration of bait fish , like herring , and their diet varies between seasons. The stomach contents of Dall's porpoises reveal that they mainly feed on cephalopods and bait fish, like capelin and sardines . Their stomachs also contained some deep-sea benthic organisms. The finless porpoise is known to also follow seasonal migrations. It

4389-470: Is dependent for one to two years, and maturity occurs after seven to ten years, all varying between species. This mode of reproduction produces few offspring, but increases the probability of each one surviving. Porpoises eat a wide variety of creatures. The stomach contents of harbour porpoises suggests that they mainly feed on benthic fish , and sometimes pelagic fish . They may also eat benthic invertebrates. In rare cases, algae, such as Ulva lactuca ,

4522-596: Is discouraged by both the International Code of Zoological Nomenclature and the International Code of Nomenclature for algae, fungi, and plants , there are some five thousand such names in use in more than one kingdom. For instance, A list of generic homonyms (with their authorities), including both available (validly published) and selected unavailable names, has been compiled by the Interim Register of Marine and Nonmarine Genera (IRMNG). The type genus forms

4655-494: Is herding, where a pod squeezes a school of fish into a bait ball . Individual members then take turns plowing through the ball, feeding on the stunned fish. Corralling is a method where dolphins chase fish into shallow water to catch them more easily. Orca and bottlenose dolphins have also been known to drive their prey onto a beach to feed on it, a behavior known as beach or strand feeding. Some species also whack fish with their flukes, stunning them and sometimes knocking them out of

4788-472: Is in effect today making it the largest direct hunt of any cetacean species in the world and the sustainability of the hunt has been questioned. Porpoises are highly affected by bycatch . Many porpoises, mainly the vaquita , are subject to great mortality due to gillnetting . Although it is the world's most endangered marine cetacean, the vaquita continues to be caught in small-mesh gillnet fisheries throughout much of its range. Incidental mortality caused by

4921-483: Is known that populations in the mouth of the Indus River migrate to the sea from April through October to feed on the annual spawning of prawns . In Japan, sightings of small pods of them herding sand lance onto shore are common year-round. Little is known about the diets of other species of porpoises. A dissection of three Burmeister's porpoises shows that they consume shrimp and euphausiids (krill). A dissection of

5054-443: Is located in a layer of blubber between the meat and the skin. When dolphin meat is eaten in Japan, it is often cut into thin strips and eaten raw as sashimi , garnished with onion and either horseradish or grated garlic , much as with sashimi of whale or horse meat ( basashi ). When cooked, dolphin meat is cut into bite-size cubes and then batter-fried or simmered in a miso sauce with vegetables. Cooked dolphin meat has

5187-450: Is nearly extinct due to bycatch in gill nets, with a predicted population of fewer than a dozen individuals. Since the extinction of the baiji , the vaquita is considered the most endangered cetacean. Some species of porpoises have been and are kept in captivity and trained for research, education and public display. Porpoises, along with whales and dolphins , are descendants of land-living ungulates (hoofed animals) that first entered

5320-458: Is rapidly declining because of bycatch in gillnets), there have been attempts of transferring some to captivity. The first and only caught for captivity were two females in 2017. Both became distressed and were rapidly released, but one of them died in the process. Soon after the project was abandoned. Only a single Burmeister's porpoise and a single spectacled porpoise have been kept in captivity. Both were stranded individuals that only survived

5453-552: Is relatively small for its size, yet they do retain a good degree of eyesight. As well as this, the eyes of a dolphin are placed on the sides of its head, so their vision consists of two fields, rather than a binocular view like humans have. When dolphins surface, their lens and cornea correct the nearsightedness that results from the refraction of light; they contain both rod and cone cells, meaning they can see in both dim and bright light. Dolphins do, however, lack short wavelength sensitive visual pigments in their cone cells indicating

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5586-419: Is seen, by some, to be a sign of highly developed, abstract thinking. Self-awareness, though not well-defined scientifically, is believed to be the precursor to more advanced processes like meta-cognitive reasoning (thinking about thinking) that are typical of humans. Research in this field has suggested that cetaceans, among others, possess self-awareness. The most widely used test for self-awareness in animals

5719-460: Is somewhat arbitrary. Although all species within a genus are supposed to be "similar", there are no objective criteria for grouping species into genera. There is much debate among zoologists about whether enormous, species-rich genera should be maintained, as it is extremely difficult to come up with identification keys or even character sets that distinguish all species. Hence, many taxonomists argue in favor of breaking down large genera. For instance,

5852-411: Is the bottlenose dolphin , and less than 50 orca were found in oceanariums in 2012. Delphinids, especially bottlenose dolphins, are able to hybridize with a wide variety of other delphinid species; wholphins are just one of many possible hybrids. Six species, sometimes referred to as "blackfish", are dolphins commonly called whales: the orca , the melon-headed whale , the pygmy killer whale ,

5985-537: Is the mirror test in which a temporary dye is placed on an animal's body, and the animal is then presented with a mirror; they then see if the animal shows signs of self-recognition. In 1995, Marten and Psarakos used television to test dolphin self-awareness. They showed dolphins real-time footage of themselves, recorded footage, and another dolphin. They concluded that their evidence suggested self-awareness rather than social behavior. While this particular study has not been repeated since then, dolphins have since passed

6118-474: Is the type species , and the generic name is permanently associated with the type specimen of its type species. Should the specimen turn out to be assignable to another genus, the generic name linked to it becomes a junior synonym and the remaining taxa in the former genus need to be reassessed. In zoological usage, taxonomic names, including those of genera, are classified as "available" or "unavailable". Available names are those published in accordance with

6251-786: The Convention on the Conservation of Migratory Species of Wild Animals (CMS). In addition, the Harbour porpoise is covered by the Agreement on the Conservation of Small Cetaceans of the Baltic, North East Atlantic, Irish and North Seas (ASCOBANS), the Agreement on the Conservation of Cetaceans in the Black Sea, Mediterranean Sea and Contiguous Atlantic Area (ACCOBAMS) and the Memorandum of Understanding Concerning

6384-665: The Dauphin de Viennois (later Dauphin of France ) through which it passed to the Counts of Forez , Albon and other French families, as well as several branches of the Bourbon family ( Count of Montpensier , Count of Beaujolais , among others) the Pandolfini of Florence, and the Delfini of Venice and Rome also used the dolphin as their "canting" armories. In the 19th century, Joseph Bonaparte adopted

6517-1068: The Dolfinarium Harderwijk , the Netherlands. In addition to the few kept in Europe, harbour porpoise were displayed at the Vancouver Aquarium (Canada) until recently. This was a female that had beached herself onto Horseshoe Bay in 2008 and a male that had done the same in 2011. They died in 2017 and 2016 respectively. Finless porpoises have commonly been kept in Japan, as well as China and Indonesia. As of 1984, ninety-four in total had been in captivity in Japan, eleven in China, and at least two in Indonesia. As of 1986, three establishments in Japan had bred them, and there had been five recorded births. Three calves died moments after their birth, but two survived for several years. This breeding success, combined with

6650-615: The Globicephalinae (round-headed whales, which include the false killer whale and pilot whale ). Delphinidae is a family within the superfamily Delphinoidea , which also includes the porpoises (Phocoenidae) and the Monodontidae ( beluga whale and narwhal ). River dolphins are relatives of the Delphinoidea. Oceanic dolphins range in size from the 1.7-metre-long (5 ft 7 in) and 50-kilogram (110-pound) Maui's dolphin to

6783-621: The International Code of Zoological Nomenclature ; the earliest such name for any taxon (for example, a genus) should then be selected as the " valid " (i.e., current or accepted) name for the taxon in question. Consequently, there will be more available names than valid names at any point in time; which names are currently in use depending on the judgement of taxonomists in either combining taxa described under multiple names, or splitting taxa which may bring available names previously treated as synonyms back into use. "Unavailable" names in zoology comprise names that either were not published according to

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6916-799: The International Plant Names Index for plants in general, and ferns through angiosperms, respectively, and Nomenclator Zoologicus and the Index to Organism Names for zoological names. Totals for both "all names" and estimates for "accepted names" as held in the Interim Register of Marine and Nonmarine Genera (IRMNG) are broken down further in the publication by Rees et al., 2020 cited above. The accepted names estimates are as follows, broken down by kingdom: The cited ranges of uncertainty arise because IRMNG lists "uncertain" names (not researched therein) in addition to known "accepted" names;

7049-472: The Middle Ages , not much was known about the biology of the dolphin and it was often depicted as a sort of fish. Traditionally, the dolphins in heraldry still may take after this notion, sometimes showing the dolphin skin covered with fish scales . In the Middle Ages , the dolphin became an important heraldic element in the coats of arms of several European noble families, the most noticeable being those of

7182-613: The World Wildlife Fund to ensure the future for this subspecies, and have placed five porpoises in another well-protected area, the He-wang-miao oxbow. Five protected natural reserves have been established in areas of the highest population density and mortality rates with measures being taken to ban patrolling and harmful fishing gear in those areas. There have also been efforts to study porpoise biology to help specialize conservation through captivation breeding. The Baiji Dolphinarium,

7315-412: The blowhole , forming an upward, steamy spout, followed by inhaling fresh air into the lungs. All porpoises have a thick layer of blubber . This blubber can help with insulation from the harsh underwater climate, protection to some extent as predators would have a hard time getting through a thick layer of fat, and energy for leaner times. Calves are born with only a thin layer of blubber, but rapidly gain

7448-503: The false killer whale , and the two species of pilot whales , but they are classified under the family Delphinidae . Recent molecular analyses indicate that several delphinid genera (especially Stenella and Lagenorhynchus ) are not monophyletic as currently recognized. Thus, significant taxonomic revisions within the family are likely. Extinct taxon, according to the Paleobiology Database. The Delphinidae are

7581-419: The nomenclature codes , which allow each species a single unique name that, for animals (including protists ), plants (also including algae and fungi ) and prokaryotes ( bacteria and archaea ), is Latin and binomial in form; this contrasts with common or vernacular names , which are non-standardized, can be non-unique, and typically also vary by country and language of usage. Except for viruses ,

7714-404: The platypus belongs to the genus Ornithorhynchus although George Shaw named it Platypus in 1799 (these two names are thus synonyms ) . However, the name Platypus had already been given to a group of ambrosia beetles by Johann Friedrich Wilhelm Herbst in 1793. A name that means two different things is a homonym . Since beetles and platypuses are both members of the kingdom Animalia,

7847-832: The 1960s resulted in the appearance of many dolphinaria around the world, making dolphins accessible to the public. Criticism and animal welfare laws forced many to close, although hundreds still exist around the world. In the United States , the best known are the SeaWorld marine mammal parks . In the Middle East the best known are Dolphin Bay at Atlantis, The Palm and the Dubai Dolphinarium . Various species of dolphins are kept in captivity. These small cetaceans are more often than not kept in theme parks, such as SeaWorld , commonly known as

7980-432: The 9.4-metre (31 ft) and 10-metric-ton (11-short-ton) orca , the largest known dolphin. Several species exhibit sexual dimorphism ; the males are larger than females. They have streamlined muscular bodies and two limbs that are modified into flippers. Though not quite as flexible as seals , some dolphins can travel at speeds 29 km/h (18 mph) for short distances. Most delphinids primarily eat fish, along with

8113-574: The Conservation of the Manatee and Small Cetaceans of Western Africa and Macaronesia. Their conservation statuses are either at least concern or data deficient . As of 2014, only 505 Yangtze finless porpoises remained in the main section of the Yangtze, with an alarming population density in Ezhou and Zhenjiang. While many threatened species decline rate slows after their classification, population decline rates of

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8246-567: The European coasts and Southern Hemisphere only much later, during the Pliocene . Recently discovered hybrids between male harbour porpoises and female Dall's porpoises indicate the two species may actually be members of the same genus . Porpoises have a bulbous head, no external ear flaps, a non-flexible neck, a torpedo shaped body, limbs modified into flippers, and a tail fin. Their skull has small eye orbits, small, blunt snouts, and eyes placed on

8379-749: The Mexican government has created a nature reserve covering the upper part of the Gulf of California and the Colorado River delta . They have also placed a temporary ban on fishing, with compensation to those affected, that may pose a threat to the vaquita. Oceanic dolphin See text . Oceanic dolphins or Delphinidae are a widely distributed family of dolphins that live in the sea . Close to forty extant species are recognised. They include several big species whose common names contain "whale" rather than "dolphin", such as

8512-541: The Romans, but mixed with a more accurate knowledge of the dolphins, as mentioned by Pliny the Elder in his "Natural history". In the art of this and subsequent periods, porpoises are portrayed with a long snout (typical of dolphins) and a high-arched head. The harbour porpoise was one of the most accessible species for early cetologists , because it could be seen very close to land, inhabiting shallow coastal areas of Europe. Much of

8645-480: The assumption that they would fare better than their dolphin counterparts due to their smaller size and shallow-water habitats. Up until the 1980s, they were consistently short-lived. Harbour porpoises have a very long captive history, with poorly documented attempts as early as the 15th century, and better documented starting in the 1860s and 1870s in London Zoo , the now-closed Brighton Aquarium & Dolphinarium, and

8778-442: The base for higher taxonomic ranks, such as the family name Canidae ("Canids") based on Canis . However, this does not typically ascend more than one or two levels: the order to which dogs and wolves belong is Carnivora ("Carnivores"). The numbers of either accepted, or all published genus names is not known precisely; Rees et al., 2020 estimate that approximately 310,000 accepted names (valid taxa) may exist, out of

8911-442: The birth of a single calf. Some species are well adapted for diving to great depths. They have a layer of fat, or blubber , under the skin to keep warm in the cold water. Although oceanic dolphins are widespread, most species prefer the warmer waters of the tropic zones, but some, like the right whale dolphin , prefer colder climates. Some have a global distribution, like the orca. Oceanic dolphins feed largely on fish and squid, but

9044-535: The bottlenose dolphin. There are also fewer than ten pilot whales , Amazon river dolphins , Risso's dolphins , spinner dolphins , or tucuxi in captivity. Two unusual and very rare hybrid dolphins, known as wholphins , are kept at the Sea Life Park in Hawaii , which is a cross between a bottlenose dolphin and a false killer whale . Also, two common /bottlenose hybrids reside in captivity: one at Discovery Cove and

9177-474: The brain that are homologous to where they are found in humans, suggesting that they perform a similar function. Brain size was previously considered a major indicator of the intelligence of an animal. Since most of the brain is used for maintaining bodily functions, greater ratios of brain to body mass may increase the amount of brain mass available for more complex cognitive tasks. Allometric analysis indicates that mammalian brain size scales at approximately

9310-508: The case of the orca, also eat marine mammals and birds. All, however, are purely carnivorous . They typically have between 100 and 200 teeth, although a few species have considerably fewer. Various methods of feeding exist among and within oceanic species, some apparently exclusive to a single population. Fish and squid are the main food, but the false killer whale and the orca also feed on other marine mammals. Orca on occasion also hunt whales larger than themselves. One common feeding method

9443-571: The conical teeth of dolphins, and lack of a pronounced beak, although some dolphins (e.g. Hector's dolphin ) also lack a pronounced beak. Porpoises, and other cetaceans , belong to the clade Cetartiodactyla with even-toed ungulates . Porpoises range in size from the vaquita , at 1.4 metres (4 feet 7 inches) in length and 54 kilograms (119 pounds) in weight, to the Dall's porpoise , at 2.3 m (7 ft 7 in) and 220 kg (490 lb). Several species exhibit sexual dimorphism in that

9576-445: The consumption of dolphin meat in Japan after tests showed that dolphin meat contained high levels of mercury . There are no known cases of mercury poisoning as a result of consuming dolphin meat, though the government continues to monitor people in areas where dolphin meat consumption is high. The Japanese government recommends that children and pregnant women avoid eating dolphin meat on a regular basis. Similar concerns exist with

9709-754: The consumption of dolphin meat in the Faroe Islands , where prenatal exposure to methylmercury and PCBs primarily from the consumption of pilot whale meat has resulted in neuropsychological deficits amongst children. Legally consuming dolphin meat in the United States would be near impossible for most due to the Marine Mammal Protection Act , which forbids "...the act of hunting, killing, capture, and/or harassment of any marine mammal..." (Exceptions are made for certain groups of people, such as Alaska Natives .) Theoretically, one could only eat

9842-498: The cornea. The olfactory lobes are absent in oceanic dolphins, suggesting that they have no sense of smell. Oceanic dolphins are not thought to have a good sense of taste, as their taste buds are atrophied or missing altogether. However, some have preferences between different kinds of fish, indicating some sort of attachment to taste. Most delphinids primarily eat fish, along with a smaller number of squid and small crustaceans, but some species specialize in eating squid, or, in

9975-825: The creation of the International Committee for the Recovery of the Vaquita (CIRVA), which has tried to prevent the accidental deaths of vaquitas by outlawing the use of fishing nets within the vaquita's habitat. CIRVA has worked together with the CITES , the Endangered Species Act , and the Marine Mammal Protection Act (MMPA) to nurse the vaquita population back to a point at which they can sustain themselves. CIRVA concluded in 2000 that between 39 and 84 individuals are killed each year by such gillnets. To try to prevent extinction,

10108-403: The depth of the body of water in which they are. Similar to the navy, some boats produce waves that attract porpoises, while others may repel them. The problem with the waves that attract is that the animal may be injured or even killed by being hit by the vessel or its propeller. The harbour porpoise, spectacled porpoise, Burmeister's porpoise, and Dall's porpoise are all listed on Appendix II of

10241-472: The dolphin energy as there is less friction while in the air. This type of travel is known as porpoising. Other reasons include orientation, social displays, fighting, non-verbal communication , entertainment and attempting to dislodge parasites . Dolphins show various types of playful behavior , often including objects, self-made bubble rings , other dolphins, or other animals. When playing with objects or small animals, common behavior includes carrying

10374-427: The dolphin equivalent of a name for humans. These signature whistles are developed during a dolphin's first year; it continues to maintain the same sound throughout its lifetime. In order to obtain each individual whistle sound, dolphins undergo vocal production learning. This consists of an experience with other dolphins that modifies the signal structure of an existing whistle sound. An auditory experience influences

10507-733: The females are larger than males. They have streamlined bodies and two limbs that are modified into flippers. Porpoises use echolocation as their primary sensory system . Some species are well adapted for diving to great depths. As all cetaceans, they have a layer of fat, or blubber, under the skin to keep them warm in cold water. Porpoises are abundant and found in a multitude of environments, including rivers ( finless porpoise ), coastal and shelf waters ( harbour porpoise , vaquita ) and open ocean ( Dall's porpoise and spectacled porpoise ), covering all water temperatures from tropical ( Sea of Cortez , vaquita ) to polar ( Greenland , harbour porpoise ). Porpoises feed largely on fish and squid, much like

10640-542: The findings that apply to all cetaceans were first discovered in porpoises. One of the first anatomical descriptions of the airways of the whales on the basis of a harbor porpoise dates from 1671 by John Ray. It nevertheless referred to the porpoise as a fish, most likely not in the modern-day sense, where it refers to a zoological group, but the older reference as simply a creature of the sea (cf. for example star-fish , cuttle-fish , jelly-fish and whale-fish ). Harbour porpoises have historically been kept in captivity, under

10773-408: The first breeding happened in 2005. Small numbers of Dall's porpoises have been kept in captivity in both the United States and Japan, with the most recent being in the 1980s. The first recorded instance of a Dall's taken for an aquarium was in 1956 captured off Catalina Island in southern California. Dall's porpoises consistently failed to thrive in captivity. These animals often repeatedly ran into

10906-443: The fleet of El Golfo de Santa Clara was estimated to be at around 39 vaquitas per year, which is over 17% of the population size. Harbour porpoises also suffer drowning by gillnetting, but on a less threatening scale due to their high population; their mortality rate per year increases a mere 5% due to this. The fishing market, historically has always had a porpoise bycatch. Today, the Marine Mammal Protection Act of 1972 has enforced

11039-446: The form "author, year" in zoology, and "standard abbreviated author name" in botany. Thus in the examples above, the genus Canis would be cited in full as " Canis Linnaeus, 1758" (zoological usage), while Hibiscus , also first established by Linnaeus but in 1753, is simply " Hibiscus L." (botanical usage). Each genus should have a designated type , although in practice there is a backlog of older names without one. In zoology, this

11172-574: The form of clicks and whistles. Oceanic dolphins are sometimes hunted in places such as Japan, in an activity known as dolphin drive hunting . Besides drive hunting, they also face threats from bycatch , habitat loss, and marine pollution . Dolphins have been depicted in various cultures worldwide. They occasionally feature in literature and film, as in the Warner Bros film Free Willy . Dolphins are sometimes kept in captivity and trained to perform in shows. The most common species of dolphin in captivity

11305-727: The generic name (or its abbreviated form) still forms the leading portion of the scientific name, for example, Canis lupus lupus for the Eurasian wolf subspecies, or as a botanical example, Hibiscus arnottianus ssp. immaculatus . Also, as visible in the above examples, the Latinised portions of the scientific names of genera and their included species (and infraspecies, where applicable) are, by convention, written in italics . The scientific names of virus species are descriptive, not binomial in form, and may or may not incorporate an indication of their containing genus; for example,

11438-628: The largest component, with 23,236 ± 5,379 accepted genus names, of which 20,845 ± 4,494 are angiosperms (superclass Angiospermae). By comparison, the 2018 annual edition of the Catalogue of Life (estimated >90% complete, for extant species in the main) contains currently 175,363 "accepted" genus names for 1,744,204 living and 59,284 extinct species, also including genus names only (no species) for some groups. The number of species in genera varies considerably among taxonomic groups. For instance, among (non-avian) reptiles , which have about 1180 genera,

11571-407: The males being larger than the females. Breathing involves expelling stale air from the blowhole , forming an upward, steamy spout, followed by inhaling fresh air into the lungs; a spout only occurs when the warm air from the lungs meets the cold external air, so it may only form in colder climates. All oceanic dolphins have a thick layer of blubber , the thickness of which depends on how far

11704-474: The meat of a dolphin which died of natural causes, which would likely be highly undesirable (and potentially dangerous). Various fishing methods, like seine fishing for tuna and the use of drift and gill nets , unintentionally kill many oceanic dolphins. Accidental bycatch in gill nets is common and poses a risk for mainly local dolphin populations. Dolphin safe labels attempt to reassure consumers that fish and other marine products have been caught in

11837-430: The mirror test. In some parts of the world, such as Taiji, Japan and the Faroe Islands , dolphins are traditionally considered as food, and are killed in harpoon or drive hunts . Dolphin meat is consumed in a small number of countries worldwide, which include Japan and Peru (where it is referred to as chancho marino , or "sea pork"). Dolphin meat is dense and such a dark shade of red as to appear black. Fat

11970-403: The most (>300) have only 1 species, ~360 have between 2 and 4 species, 260 have 5–10 species, ~200 have 11–50 species, and only 27 genera have more than 50 species. However, some insect genera such as the bee genera Lasioglossum and Andrena have over 1000 species each. The largest flowering plant genus, Astragalus , contains over 3,000 species. Which species are assigned to a genus

12103-479: The most diverse of the cetacean families, with numerous variations between species. They range in size from 1.2 m (3 ft 11 in) and 40 kg (88 lb) ( Haviside's dolphin ), to 9 m (30 ft) and 10 tonnes (orca). Most species weigh between 50 and 200 kg (110 and 440 lb). They typically have curved dorsal fins, clear 'beaks' at the front of their heads, and forehead melons , although exceptions to all of these rules are found. They have

12236-428: The name could not be used for both. Johann Friedrich Blumenbach published the replacement name Ornithorhynchus in 1800. However, a genus in one kingdom is allowed to bear a scientific name that is in use as a generic name (or the name of a taxon in another rank) in a kingdom that is governed by a different nomenclature code. Names with the same form but applying to different taxa are called "homonyms". Although this

12369-503: The nature and extent of that ability is not known. The clicks are directional and are for echolocation, often occurring in a short series called a click train. The click rate increases when approaching an object of interest. Dolphin echolocation clicks are amongst the loudest sounds made by marine animals . Bottlenose dolphins have been found to have signature whistles. These whistles are used in order for dolphins to communicate with one another by identifying an individual. It can be seen as

12502-462: The neck vertebrae, while increasing stability when swimming at high speeds, decreases flexibility, making it impossible for them to turn their head. When swimming, they move their tail fin and lower body up and down, propelling themselves through vertical movement, while their flippers are mainly used for steering. Flipper movement is continuous. Some species log out of the water, which may allow them to travel faster, and sometimes they porpoise out of

12635-421: The neck vertebrae, while increasing stability when swimming at high speeds, decreases flexibility, which means they are unable to turn their heads. Oceanic dolphins swim by moving their tail fin and rear body vertically, while their flippers are mainly used for steering. Some species log out of the water, which may allow them to travel faster. Their skeletal anatomy allows them to be fast swimmers. All species have

12768-406: The object or animal along using various parts of the body, passing it along to other members of the group or taking it from another member, or throwing it out of the water. Dolphins have also been observed harassing animals in other ways, for example by dragging birds underwater without showing any intent to eat them. Playful behaviour that involves another animal species with active participation of

12901-515: The oceans around 50 million years ago (Mya). During the Miocene (23 to 5 Mya ), mammals were fairly modern, meaning they seldom changed physiologically from the time. The cetaceans diversified, and fossil evidence suggests porpoises and dolphins diverged from their last common ancestor around 15 Mya. The oldest fossils are known from the shallow seas around the North Pacific, with animals spreading to

13034-486: The oceans. Marine mammals that make use of biosonar for orientation and communication are not only hindered by the extra noise, but may race to the surface in panic. This may lead to a bubbling out of blood gases, and the animal then dies because the blood vessels become blocked, so-called decompression sickness . This effect, of course, only occurs in porpoises that dive to great depths, such as Dall's porpoise. Additionally, civilian vessels produce sonar waves to measure

13167-537: The only place keeping the species in Denmark is the Fjord & Bælt Centre, where three rescues have been kept, along with their offspring. Among the three rescues, one (father of world's first harbour porpoise born in captivity) lived for 20 years in captivity, another for 15 years, while the third (mother of first born in captivity) is the world's oldest known harbour porpoise, being 28 years old in 2023. The typical age reached in

13300-404: The only truly dolphin-safe tuna. Loud underwater noises, such as those resulting from naval sonar use, live firing exercises, and certain offshore construction projects such as wind farms , may be harmful to dolphins, increasing stress, damaging hearing, and causing decompression sickness by forcing them to surface too quickly to escape the noise. The renewed popularity of dolphins in

13433-583: The other animal can also be observed, however. Playful human interaction with dolphins is one example, but playful interactions have been observed in the wild with a number of other species as well, including humpback whales and dogs . Oceanic dolphins are known to teach, learn, cooperate, scheme, and grieve. The neocortex of many species is home to elongated spindle neurons that, prior to 2007, were known only in hominids. In humans, these cells are involved in social conduct, emotions, judgment, and theory of mind. Cetacean spindle neurons are found in areas of

13566-489: The other at SeaWorld San Diego . Orca are well known for their performances in shows, but the number of orcas kept in captivity is very small, especially when compared to the number of bottlenose dolphins, with only 44 captive orca being held in aquaria as of 2012. The orca's intelligence , trainability, striking appearance, playfulness in captivity and sheer size have made it a popular exhibit at aquaria and aquatic theme parks. From 1976 to 1997, 55 whales were taken from

13699-404: The outer ear to the middle ear, dolphins receive sound through the throat, from which it passes through a low-impedance fat-filled cavity to the inner ear. The dolphin ear is acoustically isolated from the skull by air-filled sinus pockets, which allow for greater directional hearing underwater. Dolphins send out high frequency clicks from an organ known as a melon . This melon consists of fat, and

13832-422: The outside air's low impedance and the cochlear fluid's high impedance. In whales, and other marine mammals, there is no great difference between the outer and inner environments. Instead of sound passing through the outer ear to the middle ear, porpoises receive sound through the throat, from which it passes through a low-impedance fat-filled cavity to the inner ear. The porpoise ear is acoustically isolated from

13965-473: The poet Arion from drowning and carried him safe to land, at Cape Matapan , a promontory forming the southernmost point of the Peloponnesus . There was a temple to Poseidon and a statue of Arion riding the dolphin. Dionysus was once captured by Etruscan pirates who mistook him for a wealthy prince they could ransom. After the ship set sail Dionysus invoked his divine powers, causing vines to overgrow

14098-600: The porpoise are actually accelerating. While population decline tracked from 1994 to 2008 has been pegged at a rate of 6.06% annually, from 2006 to 2012, the porpoise population decreased by more than half. Finless porpoise population decrease of 69.8% in just a 22-year span from 1976 to 2000. 5.3%. A majority of factors of this population decline are being driven by the massive growth in Chinese industry since 1990 which caused increased shipping and pollution and ultimately environmental degradation . Some of these can be seen in damming of

14231-526: The provisions of the ICZN Code, e.g., incorrect original or subsequent spellings, names published only in a thesis, and generic names published after 1930 with no type species indicated. According to "Glossary" section of the zoological Code, suppressed names (per published "Opinions" of the International Commission of Zoological Nomenclature) remain available but cannot be used as the valid name for

14364-739: The rest of the odontocetes. Little is known about reproductive behaviour. Females may have one calf every year under favourable conditions. Calves are typically born in the spring and summer months and remain dependent on the female until the following spring. Porpoises produce ultrasonic clicks, which are used for both navigation ( echolocation ) and social communication. In contrast to many dolphin species, porpoises do not form large social groups. Porpoises were, and still are, hunted by some countries by means of drive hunting . Larger threats to porpoises include extensive bycatch in gill nets , competition for food from fisheries, and marine pollution , in particular heavy metals and organochlorides . The vaquita

14497-501: The results with harbour porpoise in Denmark and the Netherlands, proved that porpoises can be successfully bred in captivity, and this could open up new conservation options. The reopened Miyajima Public Aquarium (Japan) houses three finless porpoises. As part of an attempt of saving the narrow-ridged (or Yangtze) finless porpoise , several are kept in the Baiji Dolphinarium in China. After having been kept in captivity for 9 years,

14630-573: The river as well as illegal fishing activity. To protect the species, China's Ministry of Agriculture classified the species as being National First Grade Key Protected Wild Animal, the strictest classification by law, meaning it is illegal to bring harm to a porpoise. Protective measures in the Tian-e-Zhou Oxbow Nature Reserve has increased its population of porpoises from five to forty in 25 years. The Chinese Academy of Science 's Wuhan Institute of Hydrobiology has been working with

14763-449: The ruined palace at Knossos . Dolphins are common in Greek mythology , and many coins from ancient Greece have been found which feature a man, a boy or a deity riding on the back of a dolphin. The Ancient Greeks welcomed dolphins; spotting dolphins riding in a ship's wake was considered a good omen. In both ancient and later art, Cupid is often shown riding a dolphin . A dolphin rescued

14896-466: The same kind as other (analogous) genera. The term "genus" comes from Latin genus , a noun form cognate with gignere ('to bear; to give birth to'). The Swedish taxonomist Carl Linnaeus popularized its use in his 1753 Species Plantarum , but the French botanist Joseph Pitton de Tournefort (1656–1708) is considered "the founder of the modern concept of genera". The scientific name (or

15029-408: The scientific epithet) of a genus is also called the generic name ; in modern style guides and science, it is always capitalised. It plays a fundamental role in binomial nomenclature , the system of naming organisms , where it is combined with the scientific name of a species : see Botanical name and Specific name (zoology) . The rules for the scientific names of organisms are laid down in

15162-512: The ship where the mast and sails had been. He turned the oars into serpents, so terrifying the sailors that they jumped overboard, but Dionysus took pity on them and transformed them into dolphins so that they would spend their lives providing help for those in need. Dolphins were also the messengers of Poseidon and sometimes did errands for him as well. Dolphins were sacred to both Aphrodite and Apollo . Dolphins are sometimes used as symbols, for instance in heraldry. When heraldry developed in

15295-443: The sides of the head. Porpoises range in size from the 1.4 m (4 ft 7 in) and 54 kg (119 lb) vaquita to the 2.3 m (7 ft 7 in) and 220 kg (490 lb) Dall's porpoise . Overall, they tend to be dwarfed by other cetaceans. Almost all species have female-biased sexual dimorphism, with the females being larger than the males, although those physical differences are generally small; one exception

15428-424: The skull by air-filled sinus pockets, which allow for greater directional hearing underwater. Odontocetes send out high frequency clicks from an organ known as a melon . This melon consists of fat, and the skull of any such creature containing a melon will have a large depression. The large bulge on top of the porpoises head is caused by the melon. The porpoise eye is relatively small for its size, yet they do retain

15561-447: The skull of any such creature containing a melon will have a large depression. This allows dolphins to produce biosonar for orientation. Though most dolphins do not have hair, they do have hair follicles that may perform some sensory function. Beyond locating an object, echolocation also provides the animal with an idea on an object's shape and size, though how exactly this works is not yet understood. The eye of oceanic dolphins

15694-405: The species lives from the equator. This blubber also helps keep the animal warm providing insulation from the harsh climate or cold depths. It can also aid in protection to some extent as predators would have a hard time getting through a thick layer of fat. Calves are born with only a thin layer of blubber, but some species compensate for this with lanugos . Oceanic dolphins have two flippers on

15827-497: The specific name particular to the wolf. A botanical example would be Hibiscus arnottianus , a particular species of the genus Hibiscus native to Hawaii. The specific name is written in lower-case and may be followed by subspecies names in zoology or a variety of infraspecific names in botany . When the generic name is already known from context, it may be shortened to its initial letter, for example, C. lupus in place of Canis lupus . Where species are further subdivided,

15960-412: The standard format for a species name comprises the generic name, indicating the genus to which the species belongs, followed by the specific epithet, which (within that genus) is unique to the species. For example, the gray wolf 's scientific name is Canis lupus , with Canis ( Latin for 'dog') being the generic name shared by the wolf's close relatives and lupus (Latin for 'wolf') being

16093-403: The taxon is termed a synonym ; some authors also include unavailable names in lists of synonyms as well as available names, such as misspellings, names previously published without fulfilling all of the requirements of the relevant nomenclatural code, and rejected or suppressed names. A particular genus name may have zero to many synonyms, the latter case generally if the genus has been known for

16226-464: The underside toward the head, a dorsal fin , and a tail fin. These flippers contain four digits. Although oceanic dolphins do not possess fully developed hind limbs, some possess discrete rudimentary appendages, which may contain feet and digits. Oceanic dolphins are fast swimmers in comparison to seals who typically cruise at 11–27 km/h (7–17 mph); the orca, in comparison, can travel at speeds of up to 55.5 km/h (34.5 mph). The fusing of

16359-474: The use of safer fishing equipment to reduce bycatch. Porpoises are very sensitive to anthropogenic disturbances, and are keystone species , which can indicate the overall health of the marine environment. Populations of harbor porpoises in the North and Baltic Seas are under increasing pressure from anthropogenic causes such as offshore construction, ship traffic, fishing, and military exercises. Increasing pollution

16492-566: The values quoted are the mean of "accepted" names alone (all "uncertain" names treated as unaccepted) and "accepted + uncertain" names (all "uncertain" names treated as accepted), with the associated range of uncertainty indicating these two extremes. Within Animalia, the largest phylum is Arthropoda , with 151,697 ± 33,160 accepted genus names, of which 114,387 ± 27,654 are insects (class Insecta). Within Plantae, Tracheophyta (vascular plants) make up

16625-429: The virus species " Salmonid herpesvirus 1 ", " Salmonid herpesvirus 2 " and " Salmonid herpesvirus 3 " are all within the genus Salmonivirus ; however, the genus to which the species with the formal names " Everglades virus " and " Ross River virus " are assigned is Alphavirus . As with scientific names at other ranks, in all groups other than viruses, names of genera may be cited with their authorities, typically in

16758-477: The walls of their enclosures, refused food, and exhibited skin sloughing . Almost all Dall's porpoises introduced to aquaria died shortly after, typically within days. Only two have lived for more than 60 days: a male reached 15 months at Marineland of the Pacific and another 21 months at a United States Navy facility . As part of last-ditch effort of saving the extremely rare vaquita (the tiny remaining population

16891-434: The water, meaning jump out of the water. Their skeletal anatomy allows them to be fast swimmers. They have a very well defined and triangular dorsal fin , allowing them to steer better in the water. Unlike their dolphin counterparts, they are adapted for coastal shores, bays, and estuaries. The porpoise ear has specific adaptations to the marine environment. In humans, the middle ear works as an impedance equaliser between

17024-423: The water. Oceanic dolphins are capable of making a broad range of sounds using nasal airsacs located just below the blowhole. Roughly three categories of sounds can be identified: frequency modulated whistles, burst-pulsed sounds, and clicks. Dolphins communicate with whistle-like sounds produced by vibrating connective tissue, similar to the way human vocal cords function, and through burst-pulsed sounds, though

17157-453: The whistle development of each dolphin. Dolphins are able to communicate to one another by addressing another dolphin through mimicking their whistle. The signature whistle of a male bottlenose dolphin tends to be similar to that of his mother, while the signature whistle of a female bottlenose dolphin tends to be more distinguishable. Bottlenose dolphins have a strong memory when it comes to these signature whistles, as they are able to relate to

17290-559: The wild in Iceland, 19 in Japan and three in Argentina. These figures exclude animals that died during capture. Live captures fell dramatically in the 1990s, and by 1999, about 40% of the 48 animals on display in the world were captive-born. In Greek myths , they were seen invariably as helpers of humankind. Dolphins also seem to have been important to the Minoans , judging by artistic evidence from

17423-442: The wild is 14 years or less. Very few harbour porpoises have been born in captivity. Historically, harbour porpoises were often kept singly and those who were together often were not mature or of the same sex. Disregarding one born more than 100 years ago that was the result of a pregnant female being brought into captivity, the world's first full captive breeding was in 2007 in the Fjord & Bælt Centre, followed by another in 2009 in

17556-428: The ⅔ or ¾ exponent of the body mass. Comparison of a particular animal's brain size with the expected brain size based on such allometric analysis provides an encephalization quotient that can be used as another indication of animal intelligence. Orca have the second largest brain mass of any animal on earth, next to the sperm whale . The brain to body mass ratio in some is second only to humans. Self-awareness

17689-559: Was established in 1992 at the Institute of Hydrobiology of the Chinese Academy of Sciences in Wuhan which allowing the study of behavioral and biological factors affecting the finless porpoise, specifically breeding biology like seasonal changes in reproductive hormones and breeding behavior. Because vaquitas are indigenous to the Gulf of California, Mexico is leading conservation efforts with

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