Common dolphin

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Common dolphin
Common dolphin noaa.jpg
Common dolphin size.svg
Size compared to an average human
CITES Appendix II (CITES) [2]
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Artiodactyla
Infraorder: Cetacea
Family: Delphinidae
Genus: Delphinus
Linnaeus, 1758
Species:
D. delphis
Binomial name
Delphinus delphis
Subspecies
  • D. d. delphis
  • D. d. bairdii
  • D. d. ponticus
  • D. d. tropicalis
Delphinus delphis IUCN.png
  Range of common dolphin
Synonyms
  • Delphinus albimanus Peale, 1848
  • Delphinus algeriensis Loche, 1860
  • Delphinus capensis Gray, 1828
  • Delphinus delphus Linnaeus, 1758
  • Delphinus forsteri Gray, 1846
  • Delphinus fulvifasciatus Wagner, 1846
  • Delphinus fulvofasciatus True, 1889
  • Delphinus janira Gray, 1846
  • Delphinus loriger Wiegmann, 1846
  • Delphinus marginatus Lafont, 1868
  • Delphinus novaezealandiae Gray, 1850
  • Delphinus novaezeelandiae Wagner, 1846
  • Delphinus novaezelandiae Quoy & Gaimard, 1830
  • Delphinus vulgaris Lacépède, 1804
  • Delphinus zelandae Gray, 1853

The common dolphin (Delphinus delphis) is the most abundant cetacean in the world, with a global population of about six million. [3] Despite this fact and its vernacular name, the common dolphin is not thought of as the archetypal dolphin, with that distinction belonging to the bottlenose dolphin due to its popular appearances in aquaria and the media. However, the common dolphin is often depicted in Ancient Greek and Roman art and culture, most notably in a mural painted by the Greek Minoan civilization. [4]

Contents

It is presently the only member of the genus Delphinus. The common dolphin belongs to the subfamily Delphininae, making this dolphin closely related to the three different species of bottlenose dolphins, humpback dolphin, striped dolphin, spinner dolphin, Clymene dolphin, spotted dolphin, Fraser's dolphin, the tucuxi and Guiana dolphin. [5] The common dolphin was originally categorized into two different species (now thought to be ecotypes), the short-beaked common dolphin and the long-beaked common dolphin. However, recent evidence has shown that many populations of long-beaked common dolphins around the world are not closely related to one another and are often derived from a short-beaked ancestor and do not always share common derived characteristics. For this reason, they are no longer considered different species. [6]

Physical characteristics

Common dolphin are medium-sized dolphins; adults range between 1.9 and 2.5 m (6.2 and 8.2 ft) long, and can weigh between 80–235 kg (176–518 lb), although the range between 80–150 kg (180–330 lb) is more common. [7] Males are generally longer and heavier. [7] The color pattern on the body is unusual. The back is dark and the belly is white, while on each side is an hourglass pattern colored light grey, yellow, or gold in front and dirty grey in back. [8] They have long, thin rostra with up to 50–60 small, sharp, interlocking teeth on each side of each jaw. [9]

Taxonomy

"Short-beaked" common dolphin, Ireland Common Dolphin.jpg
"Short-beaked" common dolphin, Ireland

Despite the historic practice of lumping the entire genus Delphinus into a single species, these widely distributed dolphins exhibit a wide variety of sizes, shapes and colors. Indeed, over the past few decades, over 20 distinct species in the genus have been proposed. Scientists in California in the 1960s concluded there were two species — the long-beaked and short-beaked. The long-beaked common dolphin was thought to have a disjointed range in coastal areas in tropical and warmer temperate oceans. The range included parts of western and southern Africa, much of western South America, central California to central Mexico, coastal Peru, areas around Japan, Korea and Taiwan, and possibly near Oman. [10] Vagrants have been recorded as far north as Vancouver Island.

"Long-beaked" common dolphin, California Delphinus capensis.JPG
"Long-beaked" common dolphin, California

This analysis was seemingly confirmed by a more in-depth genetic study in the 1990s. This study also suggested a third species (D. tropicalis, common name usually Arabian common dolphin or Indo-Pacific common dolphin), characterized by an extremely long and thin beak and found in the Red Sea and Indian Ocean, might be distinguished from the long-beaked species. The current standard taxonomic works recognize this as a subspecies of D. delphis rather than a separate species.

Recent evidence has demonstrated that different populations of long-beaked common dolphins around the world are not closely related to one another and are often derived from a short-beaked ancestor (as well as not sharing common derived characters). Therefore, long-beaked and short-beaked common dolphins are now listed as the same species under the scientific name of Delphinus delphis. [11] [12] [13] Currently, the common dolphin is divided into four subspecies: [11] [14]

Fossil record

Many extinct cetacean species were once lumped into Delphinus, but have since been placed in other genera. In the late 19th century several fossil species were described, including taxa: Delphinus baltringii, Delphinus delannoy and Delphinus domeykoi. However, these species are no longer considered valid. [16] Another species known as Delphinus brevidens was reassigned to the genus Stereodelphis which is now generally considered synonymous with Squalodon . [17]

Natural history

Common dolphin, Ireland CD 3.jpg
Common dolphin, Ireland

Common dolphins live in both warm-temperate and tropical waters ranging from 40–60°N to 50°S. Long-beaked common dolphins mostly inhabit shallow, warm coastal water. [10] Short-beaked common dolphins are common "along shelf edges and in areas with sharp bottom relief such as seamounts and escarpments". [8] Common dolphins have a varied diet consisting of many species of fish and squid. This includes both mesopelagic species and epipelagic schooling species. They have been recorded to make dives up to 200 metres (660 ft) deep.

Common dolphins are a widely distributed species. They can be found around the world in both offshore and coastal waters. In the Northwest Atlantic, they can be found from Cape Hatteras North Carolina, to Newfoundland and are strongly associated with the Gulf Stream. Dolphins in this region can often be found in areas that have certain geological factors like underwater canyons and ridges because this is where up-welling occurs which result in greater nutrients. In the Eastern Pacific, common dolphins are found along the coast of California and are associated with the California current. Short-beaked common dolphins can also be found in Europe, particularly the Scotian shelf, the Black Sea and the Mediterranean. In the Southern Hemisphere, they are abundant in the southwestern Pacific, around New Zealand and southern Australia. They are generally a pelagic species that are often found in waters 650–6,500 feet deep, with the short-beaked type preferring deeper waters than the long-beaked type [18] Temperature also plays a large role in the congregation of dolphins. For example, in the western North Atlantic, almost all sightings of common dolphins took place in waters from 16 to 20 °C. However, there were common dolphin sightings in waters as low as 5 °C. [18]

Common dolphins can live in aggregations of hundreds or even thousands of dolphins. [10] Common dolphins are often seen in groups numbering several hundred individuals (with subgroups consisting of 20–30 individuals). Occasionally, different groups will come together to form mega-pods which can consist of over 10,000 dolphins. Genetic studies in the Northeast Atlantic suggest that common dolphin pods generally do not consist of close kin, but rather of members that are not closely related. Unlike many delphinids, common dolphins do not live in a matriarchal society. That being said, closely related individuals are usually found in similar geographical locations fairly consistently, providing evidence that this species displays site fidelity (at least in the Northeastern Atlantic). Male common dolphins display greater site fidelity in relation to their kin than females. [19] Common dolphin pod structure often consists of nursery pods (which includes females and calves), bachelor pods (consisting of all males) and mixed groups of males and females, including sub-adults and calves. Genetic evidence seems to indicate that common dolphins live in fission-fusion societies, where dolphins form pods that are not necessarily stable and do not necessarily consist of related individuals. It is not known if common dolphins form lifelong bonds with other individuals like the long-term male alliances seen in bottlenose dolphins. [20]

There is some evidence that common dolphins use signature whistles, similar to that of the bottlenose dolphin. These whistles are believed to serve as an acoustic label, and provide identification information similar to that of a name.  It takes approximately 1 year for a calf to learn its signature whistle after which it remains stable for the rest of a dolphin's life. In South Africa, as many as 29 common dolphin signature whistle types were detected. However, it was difficult to determine if each dolphin had its own signature whistle due to the vast number of dolphins present (over 1,000) and anthropogenic background noise. Additionally, considering the vast number of dolphins present and  taking into account their feeding and diving behavior, it appears that common dolphin signature whistles are also used for group cohesion. Another hypothesis for the function of signature whistles is that they serve as a beacon for lost individuals. [21]

Common dolphins sometimes associate with other dolphin species, such as pilot whales. [10] In the Gulf of Corinth, common dolphins frequently display mixed species association, especially with striped and Risso's dolphins. [22] Over one third of all dolphin sightings in the gulf consisted of mixed species associations that partially consisted of common dolphins. In mixed species associations, the ratio of striped to common dolphins ranged from 6:1 to 11:1. When Risso's dolphins were present (there would usually be only one or two individuals), it appeared that many of their scars were the result of interactions with striped and spinner dolphins. In many of the interactions, the Risso's dolphins would chase and herd the common dolphins toward the boat, while the common dolphins would try and swim under the Risso's dolphins. When groups of common and striped dolphins would charge at each other, the Risso's dolphin would chase the striped dolphins. Sometimes these interactions appeared to be playful, and at other times aggressive. Synchronized swimming and surfacing were commonly observed. These interactions take place in the deepest part of the Gulf, furthest from shore, and usually consist of a total of about 60 dolphins from all three species.

There have been confirmed cases of hybridization between striped and common dolphins in this region. There have been 15 cases of common dolphin and striped dolphin hybrids. Genetic and observational evidence has demonstrated that the hybrids are fertile and are capable of not only reproducing with other hybrids, but are capable of reproducing with each of the parent species. [23] Striped dolphins have been known to mate with other dolphins, as the Clymene dolphin is the result of hybrid speciation between striped and spinner dolphins. However, this is unlikely to happen with common dolphins, as their population in the Gulf of Corinth is too low. [24] Common dolphins and bottlenose dolphins have been known to interbreed in captivity. There is one confirmed case of a hybrid between a bottlenose and common dolphin in southern Spain, an important feeding ground for both species. The mother was a female bottlenose dolphin (dubbed Billie) who had spent 10 years in a common dolphin pod. Billie was observed assisting common calves reach the surface three different times and would babysit the calves after the mother went through labor. The length of the calf was similar to that of a bottlenose dolphin calf, with the lateral stripes and coloration of a common dolphin. The calf was seen with its mother almost daily on dolphin-watching tours among a nursery pod of common dolphins which also contained some immature striped dolphins. Sightings of the calf took place when temperatures were between 14 and 26 °C. The calf was mainly observed swimming alongside the mother and was seen rubbing its head on its mother, jumping backwards over its mother and engaging in flipper-to flipper, belly-to flipper and belly-to belly contact. [25]

Common dolphins have been observed bow riding on baleen whales, and they also bow ride on boats. [10] They are fast swimmers, and breaching behavior and aerial acrobatics are common with this species. [7] They are known to display altruistic behaviors to support injured members. [26] [27]

The short-beaked common dolphin has a gestation period of 10 to 11 months. [10] The newborn calf has a length of 70 to 100 centimetres (2.3 to 3.3  ft ) and weighs about 10 kilograms (22 lb). [7] For the Black Sea population, weaning occurs at between five and six months, but occurs later (up to about 19 months) in other areas. [7] [10] Typical interbirth interval ranges from one year for the Black Sea population to three years for eastern Pacific Ocean populations. [10] Age of sexual maturity also varies by location, but can range between 2 and 7 years for females and 3 and 12 years for males. [7] [10] No evidence exists of any major reproductive differences between the two species. [8] In captivity, the long-beaked common dolphin has hybridized with the common bottlenose dolphin (Tursiops truncatus). [10] One of the hybrids has been bred back to a bottlenose dolphin, demonstrating such hybrids are fertile. [28]

Human interactions

Conservation

Adult and juvenile off Sagres, Portugal Common dolphins (Delphinus delphis) adult and juvenile Sagres.jpg
Adult and juvenile off Sagres, Portugal
A common dolphin jumping off Morro Bay Nature Reserve Common Dolphin of genus Delphinus.jpg
A common dolphin jumping off Morro Bay Nature Reserve

The common dolphin is probably the most abundant cetacean species on the planet, and the overall species is listed as Least Concern on the IUCN Red List, [29] indicating that it is in no danger of extinction. Abundance has been estimated for most major portions of the species range in the Northern Hemisphere, but only for a few places in the Southern Hemisphere.  In the Pacific Ocean, there are an estimated 1,428,000 off Japan and in the temperate central Pacific Ocean, [30] 969,000 off the U.S. west coast (Carretta et al. 2019); and 2,963,000 in the eastern tropical Pacific. [31] In the Atlantic Ocean, 70,000 are estimated for the western Atlantic Ocean (Waring et al. 2019); 467,000 for European waters; [32] more than 19,400 for the Mediterranean Sea; and several tens of thousands for the Black Sea. [33]  In the southern part of the Indo-Pacific Ocean, there are an estimated 20,000-22,000 common dolphins in a small portion of southern Australia (Bilgmann et al. 2017), and 15,000-20,000 off southern Africa. [34]   There are no estimates for the population of dolphins in the northern Indian Ocean.  Taken together, these estimates suggest that well over six million common dolphins inhabit the World's oceans.

Common dolphins face a mixture of threats due to human influence. Moderate levels of metal pollutants, which are thought to negatively impact dolphin health, [35] have been measured in some populations. [36] Populations have been hunted off the coast of Peru for use as food and shark bait. In most other areas, the dolphins have not been hunted directly. Several thousand individuals have been caught in industrial trawler nets throughout their range.

Bycatch is the main threat that common dolphins face today. Short-beaked common dolphins are taken as cetacean bycatch the most in all of Europe, given that they are the most abundant dolphin in the Eastern Atlantic. About 1000 short-beaked common dolphins are bycaught in the North Atlantic each year by either tuna drift, trawling and gillnetting. The regulation is that only cetacean bycatch can not be longer than 15 meters [37] and this can lead to be a problem because short-beaked common dolphins are only about 2.7 meters. Common dolphin bycatch is a particularly important issue in Galicia Spain, via trawler fishing. [38] The bycatch of short beaked dolphins in Galicia from May to September from 2001 to 2002, consisted of 394 individuals annually. Depth was an important factor in bycatch, as incidental capture mostly took place along the continental shelf in water less than 300 m deep. Very few entrapments took place when the depth exceeded 300 m. Time of day was also important as most dolphins became trapped in trawling nets at night (most active feeding takes place at night). Most of the dolphins captured were males and had a mean age of 13+- 4.4 years. It is believed that the reason why the vast majority of bycatch consisted of males is because bachelor pods appear to be particularly abundant in Galicia from the May–October season. This fact reinforces the hypothesis that common dolphins may be sexually segregated in the Northeast Atlantic. If there was a ban on fishing in Galicia in waters than less than 250 m deep, and if there were seasonal closures, it is estimated that 78% of the dolphins would not have been caught. [38] In the Western North Atlantic, dolphins are vulnerable to swordfish driftnet fishing, with the number of males being caught as bycatch, doubling the number of females. It was also found from stranding samples that males tend to strand more. This provides evidence of sex-based habitat partitioning or pod congregation.   [38]

Common dolphins were abundant in the western Mediterranean Sea until the 1960s but occurrences there have tailed off rapidly. The reasons are not well understood, but are believed to be due to extensive human activity in the area. In the US, they are a protected species and sometimes are caught by accident in some trawler nets as by-catch, though despite this they are still quite common throughout their range. Despite these potential threats, the short-beaked common dolphin is considered to be Least Concern by the IUCN Red List, and the long-beaked common dolphin is listed as Data Deficient. [1]

The short-beaked common dolphin Delphinus delphis is listed globally on Appendix II [39] of the Convention on the Conservation of Migratory Species of Wild Animals (CMS). [40] As amended by the Conference of the Parties in 1985, 1988, 1991, 1994, 1997, 1999, 2002, 2005 and 2008. Effective: 5 March 2009 of the Convention on the Conservation of Migratory Species of Wild Animals (CMS) as it has an unfavourable conservation status or would benefit significantly from international co-operation organised by tailored agreements. The Mediterranean population of the short-beaked common dolphin is also listed on Appendix I, [39] as this population has been categorized as being in danger of extinction throughout all or a significant proportion of their range and CMS Parties strive towards strictly protecting these animals, conserving or restoring the places where they live, mitigating obstacles to migration and controlling other factors that might endanger them. In addition, the species is also covered by the Agreement on the Conservation of Small Cetaceans of the Baltic, North East Atlantic, Irish and North Seas (ASCOBANS) [41] and the Agreement on the Conservation of Cetaceans in the Black Sea, Mediterranean Sea and Contiguous Atlantic Area (ACCOBAMS). [42]

Mass stranding events

On June 8, 2009, a mass-stranding event (MSE) occurred in Falmouth Bay, Cornwall, United Kingdom. It is believed the MSE was likely caused by naval involvement, as all other factors which cause MSEs in cetaceans appear unlikely to have influenced the event. During the event, 26 common dolphins washed ashore, and about the same number floated back out to sea. There were three other MSEs in the UK before this event, all of unknown cause, from the years 1915 to 1938, but with what are believed to be lower counts of stranded dolphins. [43]

Captivity

Common dolphins are not common in captivity. But on at least three occasions, a beached common dolphin in California was nursed back to health at SeaWorld San Diego, but deemed unfit to release back to the ocean. These common dolphins remained at SeaWorld with the bottlenose dolphin exhibit. On one occasion, a male common dolphin managed to impregnate one of the female bottlenose dolphins in the exhibit, leading to four hybrid births. [28] One of the resulting common dolphin/bottlenose dolphin hybrids remained at SeaWorld, San Diego (alternately under the name Cindy or Bullet) while the other (named CJ) was kept at Discovery Cove, and was moved to SeaWorld Orlando in 2016.

Other than at SeaWorld, at least 90 common dolphins are known to have been captured from the wild and kept in captivity. Captured common dolphins are said to be difficult to keep in captivity. [9]

The behavior of captive common dolphins is not very well studied. However, a study was conducted in New Zealand of common dolphin reacting to swimmers at Marineland. [44] Unlike bottlenose dolphins (which demonstrated antagonistic or sexual behaviors), the common dolphins retreated to the refuge center of the pool, where swimmers were not allowed. They did not leave the refuge section until the swimmers left. The dolphins also surfaced much more frequently, which is a possible indicator of stress. Aggressive and playful behavior among the dolphins decreased when swimmers were present. This behavior is consistent with wild common dolphins off of New Zealand, as they actively avoid swimmers. [45]

See also

Related Research Articles

<span class="mw-page-title-main">Cetacea</span> Infraorder of mammals

Cetacea is an infraorder of aquatic mammals belonging to the order Artiodactyla that includes whales, dolphins and porpoises. Key characteristics are their fully aquatic lifestyle, streamlined body shape, often large size and exclusively carnivorous diet. They propel themselves through the water with powerful up-and-down movement of their tail which ends in a paddle-like fluke, using their flipper-shaped forelimbs to maneuver.

<span class="mw-page-title-main">Dolphin</span> Marine mammals, closely related to whales and porpoises

A dolphin is an aquatic mammal in the clade Odontoceti. Dolphins belong to the families Delphinidae, Platanistidae, Iniidae, Pontoporiidae, and possibly extinct Lipotidae. There are 40 extant species named as dolphins.

<span class="mw-page-title-main">Bottlenose dolphin</span> Genus of dolphin

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, the Indo-Pacific bottlenose dolphin, and Tamanend's bottlenose dolphin. Others, like the Burrunan dolphin, 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.

<span class="mw-page-title-main">Risso's dolphin</span> Species of marine mammal

Risso's dolphin is a marine mammal and dolphin, the only species of the genus Grampus. Some of the most closely related species to these dolphins include: pilot whales, pygmy killer whales, melon-headed whales, and false killer whales. These dolphins grow to be about 10 ft in length and can be identified by heavy scarring that appears white. They are located worldwide in cold to temperate waters, but most typically found along continental shelves due to their eating habits. Risso's dolphins have a diet that contains primarily cephalopods. They are able to search for prey at various depths due to their ability to reach depths of almost 600m. Individuals typically travel in pods ranging anywhere from 10 to 50 dolphins, with which they form tight social bonds.

<span class="mw-page-title-main">Oceanic dolphin</span> Family of marine mammals

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 the Globicephalinae. Delphinidae is a family within the superfamily Delphinoidea, which also includes the porpoises (Phocoenidae) and the Monodontidae. River dolphins are relatives of the Delphinoidea.

<span class="mw-page-title-main">Toothed whale</span> Parvorder of cetaceans

The toothed whales are a clade of cetaceans that includes dolphins, porpoises, and all other whales with teeth, such as beaked whales and the sperm whales. 73 species of toothed whales are described. They are one of two living groups of cetaceans, the other being the baleen whales (Mysticeti), which have baleen instead of teeth. The two groups are thought to have diverged around 34 million years ago (mya).

<span class="mw-page-title-main">Tropical bottlenose whale</span> Species of mammal

The tropical bottlenose whale, also known as the Indo-Pacific beaked whale or Longman's beaked whale, was considered to be the world's rarest cetacean until recently, but the spade-toothed whale now holds that position. As of 2010, the species is now known from nearly a dozen strandings and over 65 sightings. This is the only species in the genus Indopacetus.

<span class="mw-page-title-main">False killer whale</span> Species of oceanic dolphin in the genus Pseudorca

The false killer whale 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.

<span class="mw-page-title-main">Indo-Pacific bottlenose dolphin</span> Species of mammal

The Indo-Pacific bottlenose dolphin is a species of bottlenose dolphin. This dolphin grows to 2.6 m (8.5 ft) long, and weighs up to 230 kg (510 lb). It lives in the waters around India, northern Australia, South China, the Red Sea, and the eastern coast of Africa. Its back is dark grey and its belly is lighter grey or nearly white with grey spots.

<span class="mw-page-title-main">Humpback dolphin</span> Genus of mammals

Humpback dolphins are members of the genus Sousa. These dolphins are characterized by the conspicuous humps and elongated dorsal fins found on the backs of adults of the species. Humpback dolphins inhabit shallow nearshore waters along coastlines across Australia, Africa, and Asia. Their preference for these habitats exposes them to various human activities such as fisheries entanglement, boat traffic, pollution, and habitat loss. Despite these risks, their nearshore presence facilitates easy observation from land.

<span class="mw-page-title-main">Melon-headed whale</span> Species of mammal

The melon-headed whale, also known less commonly as the electra dolphin, little killer whale, or many-toothed blackfish, is a toothed whale of the oceanic dolphin family (Delphinidae). The common name is derived from the head shape. Melon-headed whales are widely distributed throughout deep tropical and subtropical waters worldwide, but they are rarely encountered at sea. They are found near shore mostly around oceanic islands, such as Hawaii, French Polynesia, and the Philippines.

<span class="mw-page-title-main">Common bottlenose dolphin</span> Species of dolphin

The common bottlenose dolphin or Atlantic bottlenose dolphin is one of three species of bottlenose dolphin in the genus Tursiops. The common bottlenose dolphin is a very familiar dolphin due to the wide exposure it receives in human care in marine parks and dolphinariums, and in movies and television programs. Common bottlenose dolphins inhabit temperate and tropical oceans throughout the world, absent only from polar waters. While formerly known simply as the bottlenose dolphin, this term is now applied to the genus Tursiops as a whole. As considerable genetic variation has been described within this species, even between neighboring populations, many experts think additional species may be recognized.

<span class="mw-page-title-main">Pantropical spotted dolphin</span> Species of mammal

The pantropical spotted dolphin is a species of dolphin found in all the world's temperate and tropical oceans. The species was beginning to come under threat due to the killing of millions of individuals in tuna purse seines. In the 1980s, the rise of "dolphin-friendly" tuna capture methods saved millions of the species in the eastern Pacific Ocean and it is now one of the most abundant dolphin species in the world.

<span class="mw-page-title-main">Atlantic white-sided dolphin</span> Species of mammal

The Atlantic white-sided dolphin is a distinctively coloured dolphin found in the cool to temperate waters of the North Atlantic Ocean.

<span class="mw-page-title-main">Tethys Research Institute</span>

The Tethys Research Institute is a non-profit research organisation founded in 1986 to support marine conservation through science and public awareness and by participating in the international conservation process. Tethys' activities are mainly carried out in the Mediterranean Sea, although research programmes have been conducted also in the Black Sea, the North Atlantic Ocean, the Caribbean, the Red Sea and Antarctica. The results of these activities have been presented in scientific publications as well as in meetings, workshops and conferences.

<span class="mw-page-title-main">Agreement on the Conservation of Cetaceans of the Black Sea, Mediterranean Sea and Contiguous Atlantic Area</span> International treaty protecting cetaceans

The Agreement on the Conservation of Cetaceans of the Black Sea, Mediterranean Sea and contiguous Atlantic Area, or ACCOBAMS, is a regional international treaty that binds its States Parties on the conservation of Cetacea in their territories. The Agreement aims is to reduce threats to Cetaceans in the Mediterranean and Black Seas, as well as in the contiguous Atlantic area west of the Straits of Gibraltar.

<i>Brucella ceti</i> Species of bacterium

Brucella ceti is a gram negative bacterial pathogen of the Brucellaceae family that causes brucellosis in cetaceans. Brucella ceti has been found in both classes of cetaceans, mysticetes and odontocetes. Brucellosis in some dolphins and porpoises can result in serious clinical signs including fetal abortions, male infertility, neurobrucellosis, cardiopathies, bone and skin lesions, stranding events, and death.

Cetaceans form an infra-order of marine mammals. In 2020, approximately 86 species of cetaceans had been identified worldwide. Among these species, at least 35 have been sighted in the wider Caribbean region with very widespread distribution and density variations between areas. Caribbean waters are a preferred breeding site for several species of mysticeti, who live further north the rest of the year. The tucuxi and the boto live at the southern periphery of the Caribbean region in the freshwaters of the Amazon River and surrounding drainage basins.

References

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  6. ↑ "Long-beaked common dolphin". Archived from the original on 2023-03-21. Retrieved 2020-07-10.
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  16. ↑ Gutstein, Carolina (2015). "Cetáceos fósiles de Chile: Contexto evolutivo y paleobiogeográfico". Publicación Ocasional del Museo Nacional de Historia Natural, Chile. 63: 339–383.
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  18. 1 2 Chavez-Rosales, Samuel; Palka, Debra L.; Garrison, Lance P.; Josephson, Elizabeth A. (December 2019). "Environmental predictors of habitat suitability and occurrence of cetaceans in the western North Atlantic Ocean". Scientific Reports. 9 (1): 5833. Bibcode:2019NatSR...9.5833C. doi:10.1038/s41598-019-42288-6. ISSN   2045-2322. PMC   6456503 . PMID   30967576.
  19. ↑ Ball, Laura; Shreves, Kypher; Pilot, Małgorzata; Moura, André E. (2017-07-21). "Temporal and geographic patterns of kinship structure in common dolphins (Delphinus delphis) suggest site fidelity and female-biased long-distance dispersal". Behavioral Ecology and Sociobiology. 71 (8): 123. Bibcode:2017BEcoS..71..123B. doi:10.1007/s00265-017-2351-z. ISSN   1432-0762. PMC   5522516 . PMID   28794579.
  20. ↑ Viricel, Amélia; Strand, Allan E.; Rosel, Patricia E.; Ridoux, Vincent; Garcia, Pascale (December 2008). "Insights on common dolphin (Delphinus delphis) social organization from genetic analysis of a mass-stranded pod". Behavioral Ecology and Sociobiology. 63 (2): 173–185. Bibcode:2008BEcoS..63..173V. doi:10.1007/s00265-008-0648-7. ISSN   0340-5443. S2CID   25991354.
  21. ↑ Fearey, J.; Elwen, S. H.; James, B. S.; Gridley, T. (September 2019). "Identification of potential signature whistles from free-ranging common dolphins (Delphinus delphis) in South Africa". Animal Cognition. 22 (5): 777–789. doi:10.1007/s10071-019-01274-1. hdl: 2263/70689 . ISSN   1435-9448. PMID   31177344. S2CID   176078258.
  22. ↑ Neumann, Dirk R.; Orams, Mark B. (2003-01-01). "Feeding behaviours of short-beaked common dolphins, Delphinus delphis, in New Zealand". Aquatic Mammals. 29 (1): 137–149. doi:10.1578/016754203101023997. ISSN   0167-5427.
  23. ↑ Antoniou, Aglaia; Frantzis (2018). "Evidence of introgressive hybridization between Stenella coeruleoabla and Delphinus delphis in the Greek Seas". Molecular Phylogenetics and Evolution. 129: 325–337. Bibcode:2018MolPE.129..325A. doi:10.1016/j.ympev.2018.09.007. PMID   30218775. S2CID   52279448.
  24. ↑ Aglaia, Antoniou (2018). "Evidence of introgressive hybridization between Stenella coeruleoabla and Delphinus delphis in the Greek Seas". Molecular Phylogenetics and Evolution. 129: 325–337. Bibcode:2018MolPE.129..325A. doi:10.1016/j.ympev.2018.09.007. PMID   30218775. S2CID   52279448.
  25. ↑ Espada, Rocío; Olaya-Ponzone, Liliana; Haasova, Luisa; Martín, Estefanía; García-Gómez, José C. (2019-04-16). "Hybridization in the wild between Tursiops truncatus (Montagu 1821) and Delphinus delphis (Linnaeus 1758)". PLOS ONE. 14 (4): e0215020. Bibcode:2019PLoSO..1415020E. doi: 10.1371/journal.pone.0215020 . ISSN   1932-6203. PMC   6467441 . PMID   30990845.
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  28. 1 2 Zornetzer H.R.; Duffield D.A. (October 1, 2003). "Captive-born bottlenose dolphin × common dolphin (Tursiops truncatus × Delphinus capensis) intergeneric hybrids". Canadian Journal of Zoology. 81 (10): 1755–1762. Bibcode:2003CaJZ...81.1755Z. doi:10.1139/z03-150.
  29. ↑ Hammond, P.S. (2008). "Delphinus delphis, Short-beaked Common Dolphin".
  30. ↑ Kanaji, Yu; Yoshida, Hideyoshi; Okazaki, Makoto (2017-03-04). "Spatiotemporal variations in habitat utilization patterns of four Delphinidae species in the western North Pacific, inferred from carbon and nitrogen stable isotope ratios". Marine Biology. 164 (4): 65. Bibcode:2017MarBi.164...65K. doi:10.1007/s00227-017-3107-z. ISSN   1432-1793. S2CID   90520472.
  31. ↑ http://citeseerx.ist.psu.edu/messages/downloadsexceeded.html . Retrieved 2020-07-22.{{cite web}}: Missing or empty |title= (help)
  32. ↑ Hammond, P.S. (2017). "Estimates of cetacean abundance in European Atlantic waters in summer 2016 from the SCANS-III aerial and shipboard surveys".{{cite journal}}: Cite journal requires |journal= (help)
  33. ↑ Birkun (2006). "Short-beaked common dolphin (Delphinus delphis ponticus): Black Sea subspecies". UCN Centre for Mediterranean Cooperation: 16–22.
  34. ↑ Cockcroft, Vic (1990). "Seasonal distribution and density of common dolphins Delphinus delphis of the south-east coast of southern Africa". South African Journal of Marine Science. 9: 371–377. doi:10.2989/025776190784378853.
  35. ↑ Lavery, T. J.; Kemper, C.; Sanderson, K.; Schultz, C. G.; Coyle, P.; Mitchell, J. G.; Seuront, L. (2009). "Heavy metal toxicity of kidney and bone tissues in South Australian bottlenose dolphins (Tursiops aduncus)" (PDF). Marine Environmental Research. 67 (1): 1–7. doi:10.1016/j.marenvres.2008.09.005. PMID   19012959.
  36. ↑ Lavery, T.J.; Butterfield, N.; Kemper, C.M.; Reid, R.J. & Sanderson, K. (1991). "Induction of labor using intracervical prostaglandin E2 gel: The outcome". Journal of the Medical Association of Thailand = Chotmaihet Thangphaet. 74 (11): 491–7. PMID   1800604.
  37. ↑ Mannocci, L; Dabin, W; Augeraud-Véron, E; Dupuy, JF; Barbraud, C; Ridoux, V (2012). Reina, Richard (ed.). "Assessing the Impact of Bycatch on Dolphin Populations: The Case of the Common Dolphin in the Eastern North Atlantic". PLOS ONE. 7 (2): e32615. Bibcode:2012PLoSO...732615M. doi: 10.1371/journal.pone.0032615 . PMC   3290591 . PMID   22393423.
  38. 1 2 3 Fernández-Contreras, M. M.; Cardona, L.; Lockyer, C. H.; Aguilar, A. (2010-11-01). "Incidental bycatch of short-beaked common dolphins (Delphinus delphis) by pairtrawlers off northwestern Spain". ICES Journal of Marine Science. 67 (8): 1732–1738. doi: 10.1093/icesjms/fsq077 . ISSN   1095-9289.
  39. 1 2 Appendices I and II of the Convention on the Conservation of Migratory Species of Wild Animals (CMS). effective 5 March 2009
  40. ↑ Convention on Migratory Species page on the Short-beaked common dolphin. Cms.int. Retrieved on 2014-01-04.
  41. ↑ Agreement on the Conservation of Small Cetaceans of the Baltic, North East Atlantic, Irish and North Seas. Ascobans.org. Retrieved on 2014-01-04.
  42. ↑ Agreement on the Conservation of Cetaceans in the Black Sea, Mediterranean Sea and Contiguous Atlantic Area. Accobams.org. Retrieved on 2014-01-04.
  43. ↑ Jepson, P. D.; Deaville, R.; Acevedo-Whitehouse, K.; Barnett, J.; Brownlow, A.; Brownell Jr, R. L.; Clare, F. C.; Davison, N.; Law, R. J.; Loveridge, J.; MacGregor, S. K.; Morris, S.; Murphy, S. A.; Penrose, R.; Perkins, M. W.; Pinn, E.; Seibel, H.; Siebert, U.; Sierra, E.; Simpson, V.; Tasker, M. L.; Tregenza, N.; Cunningham, A. A.; Fernández, A. (2013). Fahlman, Andreas (ed.). "What Caused the UK's Largest Common Dolphin (Delphinus delphis) Mass Stranding Event?". PLOS ONE. 8 (4): e60953. Bibcode:2013PLoSO...860953J. doi: 10.1371/journal.pone.0060953 . PMC   3640001 . PMID   23646103.
  44. ↑ "Behavioural responses of captive common dolphins Delphinus delphis to a 'Swim-with-Dolphin' programme". Applied Animal Behaviour Science. 2003.
  45. ↑ Kyngdon, D. (2003). "Behavioural responses of captive common dolphins Delphinus delphis to a 'Swim-with-Dolphin' programme". Applied Animal Behaviour Science. 81 (2): 163–170. doi:10.1016/S0168-1591(02)00255-1.

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