Tag: Dolphin

Spinner Dolphin

Spinner dolphin

The spinner dolphin (also known as the long-snouted dolphin (distinguishing it from the Clymene dolphin – which is often called the short snouthed spinner dolphin) is a small dolphin found in off-shore tropical waters around the world. It is famous for its spinning  along its length, as it leaps from the water. It is a member of the family Delphinidae of toothed whales.

The four named subspecies are:

  • Eastern spinner dolphin, found from the tropical eastern Pacific.
  • Central American or Costa Rican spinner dolphin, also found in the tropical eastern Pacific.
  • Gray’s or Hawaiian spinner dolphin, from the central Pacific Ocean around Hawaii but represents a mixture of broadly similar subtypes found worldwide.
  • Dwarf spinner dolphin, first found in the Gulf of Thailand.

The species, though, displays greater variety than these subspecies might indicate. A hybrid form characterized by its white belly inhabits the eastern Pacific. Other less distinct groupings inhabit other oceans.The species name comes from the Latin word for “long-beaked.”

Spinner dolphins are small cetaceans with a slim build. Adults are 129–235 cm long and weigh 23–79 kg. This species has an elongated rostrum and a triangular or subtriangular dorsal fin. Spinner dolphins generally have three colours, one on the dorsal fin, one on the underside and one on the upper-side. Also, a dark band runs from the eye to the flipper, bordered above by a thin, light line. However, the spinner dolphin has more geographic variation in form and coloration than other cetaceans. In the open waters of eastern Pacific, dolphins have relatively small skulls with short rostra. A dwarf form of spinner dolphin occurs around southeast Asia. In these same subspecies, a dark dorsal cape dims their tripartite colour patterns Further offshore, subspecies tend to have a paler and less far-reaching cape.] In certain subspecies, some males may have upright fins that slant forward.[8] Some populations of spinner dolphin found in the eastern Pacific have backwards-facing dorsal fins, and males can have dorsal humps and upturned caudal flukes.

The spinner dolphin lives in nearly all tropical and subtropical waters between 40°N and 40°S. The species primarily inhabits coastal waters, islands, or banks. However, in the eastern tropical Pacific, spinner dolphins live far from shore. Some studies suggest they use different areas at different times of the year.

The spinner dolphin feeds mainly on small mesopelagic fish, squids, and sergestid shrimps, and will dive 200–300 m to feed on them. Spinner dolphins of Hawaii are nocturnal feeders and forage in deep scattering layers, which contain many species. The dwarf spinner dolphin may feed mostly on benthic fish in reefs and shallow water. Off Oahu, Hawaii, spinner dolphins forage at night and cooperatively herd their prey into highly dense patches. They swim around the prey in a circle and a pair may swim through the circle to make a catch. Spinner dolphins are in turn preyed on by sharks. Other possible predators include the killer whale, the false killer whale, the pygmy killer whale and the short-finned pilot whale. They are susceptible to parasites, and are known to exhibit both external ones like barnacles and remoras as well as internal parasites.


Due to the spinner dolphin foraging and feeding at night, in certain regions, such as Hawaii and northern Brazil, dolphins spend the daytime resting in shallow bays near deep water. Spinner dolphins rest as a single unit, moving back and forth slowly in a tight formation but just out of contact with one another. These resting behaviours are observed for about four to five hours daily. During rest periods, spinner dolphins rely on vision rather than echolocation. At dusk, they travel offshore to feed. They travel along the shore during foraging trips, and the individuals that occupy the same bay may change daily. Some individual dolphins do not always go to a bay to rest; however, in Hawaii, dolphins do seem to return to the same site each trip.

Spinner dolphins live in an open and loose social organization. The spinner dolphins of Hawaii live in family groups, but also have associations with others beyond their groups. Mothers and calves form strong social bonds. Spinner dolphins seem to have a promiscuous mating system, with individuals changing partners for up to some weeks. A dozen adult males may gather into coalitions. Vocalizations of spinner dolphins include whistles, which may be used to organize the school, burst-pulse signals, and echolocation clicks. The spinner dolphin has a 10-month gestation period, and mothers nurse their young for one to two years. Females are sexually mature at four to seven years, with three-year calving intervals, while males are sexually mature at seven to 10 years. Spinner dolphins live for about 20-25 years old. Breeding is seasonal, more so in certain regions than others.

Although most spinner dolphins are found in the deeper waters offshore of the islands, the rest of the Hawaiʻi population has a more coastal distribution. During daytime hours, the island-associated stocks of Hawaiian spinner dolphins seek sanctuary in nearshore waters, where they return to certain areas to socialize, rest, and nurture their young.

They get their name for their spinning jumps, a spinner dolphin comes out of the water front first and twists its body as it rises into the air. When it reaches its maximum height, the dolphin descends back into the water, landing on its side. A dolphin can make two to seven spins in one leap; the swimming and rotational speed of the dolphin as it spins underwater affects the number of spins it can do while airborne. These spins may serve several functions. Some of these functions are believed by experts to be acoustic signalling or communication. Another reason is to remove ectoparasites such as remoras. Dolphins may also make nose-outs, tail slaps, flips, head slaps, “salmon leaps”, and side and back slaps.

The protected status of spinner dolphins are CITES Appendix II and Marine Mammal Protection Act (MMPA) protected throughout its range as well as MMPA depleted in its eastern stock. Tens of thousands of spinner dolphins, mostly eastern and white-bellied varieties, were killed in the 30 years after purse seine fishing for tuna began in the 1950s; The process killed probably half of all eastern spinner dolphins. They have also been contaminated by pollutants such as DDT and PCBs. Spinner dolphins, as with other species affected by ETP tuna purse-seine fishing, are managed nationally by the coastal countries and internationally by the IATTC. The IATTC has imposed annual stock mortality limits on each purse seine and promulgated regulations regarding the safe release of dolphins. The eastern tropical Pacific and Southeast Asian populations of the spinner dolphin are listed on Appendix II of the Convention on the Conservation of Migratory Species of Wild Animals (CMS), since they have an unfavourable conservation status or would benefit significantly from international co-operation organized by tailored agreements. In addition, the spinner dolphin is covered by Memorandum of Understanding for the Conservation of Cetaceans and Their Habitats in the Pacific Islands Region (Pacific Cetaceans MoU) and the Memorandum of Understanding Concerning the Conservation of the Manatee and Small Cetaceans of Western Africa and Macaronesia (Western African Aquatic Mammals MoU). Spinner dolphins are susceptible to disease and two of the recorded diseases within them are toxoplasmosis and cetacean morbillivirus. The number of cases reported however is fairly low in the species.

Spinner dolphins in Hawaii receive multiple daily visits to their near-shore resting grounds, with boats taking people out daily to snorkel and interact with the local dolphin population. Such activities are increasingly coming under criticism on the grounds of possible harm to the dolphins, and efforts are being made both to educate the public in order to minimise human impact on the dolphins, and to bring in regulations to govern these activities. In 2023, 33 swimmers were arrested for reportedly harassing dolphins off the coast of the Big Island of Hawaii. The swimmers reportedly broke federal law by swimming within 45 meters (50 yards) of the dolphins. The ban went into effect in 2021 due to dolphins not getting enough rest during the day to forage for food at night. The swimmers were caught by drone footage pursuing the dolphins as they tried to escape.

We are eager to work with people who run boats to see these animals – provided they are run with due care for the animals. Do get in touch, or fill in a form you will find in ‘List your wild place’ at the top of the page (or click here).

Indo-pacific bottlenose dolphin

Indo-Pacific Bottlenose dolphin

The Indo-Pacific bottlenose dolphin is a species of Bottlenose dolphin. This dolphin grows to 2.6 m long, and weighs up to 230 kg . It lives in the waters around northern Australia , South China, the Red Sea, and the eastern coast of Africa. Its back is dark grey and its underside is lighter grey or nearly white with grey spots. The Indo-Pacific bottlenose dolphin is usually smaller than the Common bottlenose dolphin, has a proportionately longer Rostrum, and has spots on its belly and lower sides. It also has more teeth than the common bottlenose dolphin — 23 to 29 teeth on each side of each jaw compared to 21 to 24 for the common bottlenose dolphin.

Much of the old scientific data in the field combine data about the Indo-Pacific bottlenose dolphin and the common bottlenose dolphin into a single group, making it effectively useless in determining the structural differences between the two species. The IUCN lists the Indo-Pacific bottlenose dolphin as “near threatened” in their Red List of endangered species.

Until 1998, all bottlenose dolphins were considered members of the single species Tursiops truncatus. In that year, the Indo-Pacific bottlenose dolphin was recognized as a separate species. Both species are thought to have split during the mid-Pleistocene, about 1 million years ago. Some evidence shows the Indo-Pacific bottlenose dolphin may actually be more closely related to certain dolphin species in the Delphinus (genus), especially the “Atlantic spotted dolphin”, than it is to the common bottlenose dolphin. However, more recent studies indicate that this is a consequence of reticulate evolution (such as past hybridization between Stenella and ancestral Tursiops and incomplete lineage sorting, and thus support truncatus and T. aduncus belonging to the same genus. Burrunan dolphin T. (aduncus) australis has been alternately considered its own species, a subspecies of T. truncatus, or a subspecies of T. aduncus. Following the results of a 2020 study, the American Society of Mammologists presently classifies it as a subspecies of T. aduncus. The same study delineated 3 distinct lineages within T. aduncus which could each be their own subspecies: an Indian Ocean lineage, an Australasian lineage, and the Burrunan dolphin. The Society for Marine Mammalogy does not recognize the Burrunan dolphin as a distinct species or subspecies, citing the need for further research. Indo-Pacific bottlenose dolphins are very similar to common bottlenose dolphins in appearance. Common bottlenose dolphins have a reasonably strong body, moderate-length beak, and tall, curved dorsal fins; whereas Indo-Pacific bottlenose dolphins have a more slender body build and their beak is longer and more slender. 

Indo-Pacific bottlenose dolphins feed on a wide variety of fish Cephalopod, Squid, researchers looked at the feeding ecology of Indo-Pacific bottlenose dolphins by analysing the stomach contents of ones that got caught in the gillnet fisheries off Zanzibar, Tanzania.  Indo-Pacific bottlenose dolphins live in groups that can number in the hundreds, but groups of five to 15 dolphins are most common. 

In some parts of their range, they spend time with the common bottlenose dolphin and other dolphin species, such as the humpback dolphin. The peak mating and calving seasons are in the spring and summer, although mating and calving occur throughout the year in some regions. Gestation period is about 12 months. Calves are between 0.84 and 1.5 Meters, and weigh between 9 and 21kg. The calves are weaned between 1.5 and 2.0 years, but can remain with their mothers for up to 5 years, some mothers will give birth again, shortly before the 5 years are up. 

In some parts of its range, this dolphin is subject to predation by sharks. 

Its lifespan is more than 40 years. Indo-Pacific bottlenose dolphins located in Shark Bay, Australia, have been observed using sponges as tools in a practice called “sponging”. A dolphin breaks a marine sponge off the sea floor and wears it over its rostrum, apparently to probe substrates for fish, possibly as a tool. Spontaneous ejaculation in an aquatic mammal was recorded in a wild Indo-Pacific bottlenose dolphin near Mikura Island, Japan, in 2012. Indo-Pacific bottlenose dolphins have been observed to swim near and rub themselves against specific types of corals and sponges. A team of scientists followed up on this behaviour and discovered metabolites with antibacterial, antioxidative, and hormonal activities in the corals and sponges, suggesting that they might be used by the dolphins to treat skin infections. its near-shore distribution, though, makes it vulnerable to environmental degradation, direct exploitation, and problems associated with local fisheries. 

The major predators of this species are typically sharks, and may include humans, killer whales, and sting rays. In the early 1980s, many were deliberately killed in a Taiwanese driftnet fishery in the Arafura Sea, off north western Australia. Large-mesh nets set to protect bathers from sharks in South Africa and Australia have also resulted in a substantial number of deaths. Gillnets are also having an impact, and are a problem throughout most of the species’ range.

These small cetaceans are commonly found in captivity, causing conservation concerns, including the effects of removing the animals from their wild populations, survival of cetaceans during capture and transport and while in captivity, and the risks to wild populations and ecosystems of accidentally introducing alien species and spreading epizootic diseases, especially when animals have been transported over long distances and are held in sea pens.

Bottlenose dolphins are the most common captive cetaceans on a global scale. Prior to 1980, more than 1,500 bottlenose dolphins were collected from the United States, Mexico, and the Bahamas, and more than 550 common and 60 Indo-Pacific bottlenose dolphins were brought into captivity in Japan. By the late 1980s, the United States stopped collecting bottlenose dolphins and the number of captive-born animals in North American aquaria has increased from only 6% in 1976 to about 44% in 1996. South Korea, in the 2010s, environmental groups and animal protection groups led a campaign ko:2013 to release southern bottlenose dolphins illegally captured by fishermen and trapped in Jeju Island.

In a study on three populations of Indo-Pacific bottlenose dolphins in Japan, the characteristics of acoustic signals are believed to be affected by the acoustic environments among habitats, and geographical variation in animal acoustic signals can result from differences in acoustic environments; therefore, the characteristics of the ambient noise in the dolphins’ habitats and the whistles produced were compared. Ambient noise was recorded using a hydrophone located 10 m below the surface and whistles were recorded by using an underwater video system. The results showed dolphins produced whistles at varying frequencies with greater modulations when in habitats with less ambient noise, whereas habitats with greater ambient noise seem to cause dolphins to produce whistles of lower frequencies and fewer frequency modulations. Examination of the results suggest communication signals are adaptive and are selected to avoid the masking of signals and the decrease of higher-frequency signals. They concluded ambient noise has the potential to drive the variation in whistles of Indo-Pacific bottlenose dolphin populations.

Small, motorized vessels have increased as a source of anthropogenic noise due to the rise in popularity of wildlife viewing such as whale watching. Another study showed powerboat approaches within 100 m altered the dolphin surface behaviour from traveling to milling, and changed their direction to travel away from the powerboat. When the powerboat left the area and its noise ceased, the dolphins returned to their preceding behaviour in the original direction.

In Shark Bay, Western Australia, on dolphin behavioural responses showed significant changes in the behaviour of targeted dolphins were found when compared with their behaviour before and after approaches by small watercraft. Dolphins in the low-traffic site showed a stronger and longer-lasting response than dolphins in the high-traffic site. These results are believed to show habituation of the dolphins to the vessels in a region of long-term vessel traffic. However, when compared to other studies in the same area, moderated responses, rather, were suggested to be because those individuals sensitive to vessel disturbance left the region before their study began. Although these studies do show statistical significance for the effects of whale-watching boats on behaviour, what these results mean for long-term population viability is not known. The Shark Bay population has been forecast to be relatively stable with little variation in mortality over time. The Indo-Pacific bottlenose dolphin populations of the Arafura and the Timor Sea are listed on Appendix II of the Convention on the Conservation of Migratory Species of Wild Animals “Bonn Convention”. They are listed on Appendix II as they have an unfavourable conservation status or would benefit significantly from international co-operation organised by tailored agreements. The Indo-Pacific bottlenose dolphin is also covered by Memorandum of Understanding for the Conservation of Cetaceans and Their Habitats in the Pacific Islands Region Adelaide Dolphin Sanctuary “Marine protected area”  in the Australian state of South Australia Gulf St Vincent, which was established in 2005 for the protection of a resident population of Indo-Pacific bottlenose dolphins.

When we have links for viewing these species, they will appear below video and the news section

Atlantic spotted dolphin

Atlantic Spotted dolphin

Found in the tropical and warm temperate waters of the Atlantic. While currently there is no recognized subspecies, there is a large spotty variant, found in the waters off Florida – while it is not yet recognized as a separate species or subspecies, this one may well change in the future. In the Bahamas, they have been observed mating with bottlenose dolphins.

Smaller than many dolphin species, they grow to a maximum of around 2.25m and have a range of 10 different vocalizations.

Given their similar look to other dolphins in their range, it is hard to get accurate population numbers, but the population is beleived to be at least 100,000.

Should you work in tourism or conservation of this species do get in touch.

Those who work in conservation, would be able to share news with the world. For those who work in tourism, we would love to list your services – and help people find you.

Any listings, will appear at the bottom of the page.

Clymene Dolphin

Clymene Dolphin

Also known as sort-snouted spinner dolphins, the dolphin is found in the Atlantic. It is the only confirmed case of a species developing from hybrids between 2 species – the Spinner and Striped dolphin.

Looking like spinner dolphins, but with short beak and the dorsal fin is smaller and less erect. They spend most of their lives in waters 100m or deeper. They feed on squid and schooling fish. They are predated by cookie-cuttied sharks.

When they jump, they do spin, though not as often or as much as spinner dolphins.

There are 3 distinct populations – North Atlantic, South Atlantic and Gulf of Mexico, though it is thought that the boundary between Gulf of Mexico and South Atlantic is not firm, as individuals will move between the 2. The Gulf of Mexico population is thought to be roughly 6500.

The West African population is considered appendix ii of cites.

There is a video below. Below this, will be a list of any mentions this species has had on this blog (if any)

Guiana dolphin

Guiana dolphin

The Guiana dolphin (also known as estuarine dolphin or costero) is a dolphin which lives alongside central and Southern America. It was agreed as a separate species back in 2007. It looks like a bottlenose dolphin (though smaller at 2.1m. They do not bowride, but avoid them.

It has an electroreceptive sense – the suggestion is that all toothed whales have this, but it is unclear. It was described as a separate species back in 1864 (from the Tucuxi). This was questioned for some time, but is certainly confirmed from now.

It is found in estuaries and similar up and down the coast. The population in Guanabara bay is currently near Rio de Janeiro, down from 70 in 1995 and 400 in 1985.

Below is some footage of some of these dolphins. Below that is a list of mentions on this website (whether there is currently, we hope there will be in the future).

Australian Humpback dolphin

Australian Humpback dolphin

While there is no clear scientific estimate for the population of this dolphin, its population is certainly a few thousand. They are found between Northern Australia and Southern New Guinea. It was only described in 2014. It is most closely related to the Chinese humpback dolphin.

They suffer incidental capture in gill nets as other dolphins do. What is clear, is that more study is needed to fully understand the situation.

Indo-Pacific humpback dolphin

Indo- Pacific humpback dolphin

Found in the eastern Indian and western Pacific oceans, this dolphin inhabits coastal waters in this part of the world. It is also known as the Chinese White dolphin

Coloured grey, pink or white (the pink colour comes from blood vessels near the surface rather than from pigmentation) they have a length of 2m-3.5m in length and a weight of 150kg-230kg. They generally spend their time in groups not larger than 10 individuals.

These are not dolphins who go under for long periods of time, with adults rarely diving for more than 4 minutes. Similar threats to other dolphins, include coastal developments, water pollution, overfishing and an increased number of boats in the water. In 2015 it was classified as vulnerable.

A small population of the dolphins (158) live close to Hong Kong and many have succumbed as a result of toxins ingested from the water.

Because they spend much of their time in shallow water close to the shore, they are more at risk to pollution from things like plastic that can wash into the sea. Plastic also makes it harder or impossible for the dolphins to locate fish with echolocation as a result of the extra things in the body of water. 

Below here is a section which will list every time they have been mentioned on the website. Below that, is a video of these animals. Below that you will find any links (as we make them) which will help you see these animals in the wild.

Atlantic humpback dolphin

Atlantic Humpback Dolphin

The Atlantic humpback dolphin is a dolphin species that is found on the west coastal areas of Africa. Unfortunately the IUCN classes it as critically endangered. Apart from their difference in range with the Indo-Pacific dolphin, they are also different in appearance, particularly colouring. 

It is found along the coast from the Sahara to Angola, generally in water less than 20m deep. It is generally shy, does not ride the bow wave of boats and ariel jumps are pretty rare. Usually found in groups of 1-8, occasionally they have been seen in groups of 20-40.

Generally they look for food in the shallows, and occasionally right in the surf. They have been known to engage in cooperative fishing methods with Mauritanian Imraguen fishermen. They do this by driving the fish towards the shore and into the nets. They favour inshore fish such as mullet.

As in many other parts of the world, and other dolphin species, one of the biggest threats they face is incidental capture in gill nets.

It is considered critically endangered, partly because it has been shown to be damaged by coastal development, and this is increasingly common in its range. We are eager to support its future survival, through any tourism (this helps giving value to the species, and therefore makes sure that local people are invested in its future survival. If you work in tourism of this species, click on the “list your wild place” link on the home page. These links when added, will be added at the bottom of the page. If you work in conservation of this species, do join as a member, we are keen to publish any news that you might have.

Fraser’s dolphins

Frasers Dolphin

Generally found in the deep waters of the Pacific Ocean, though also seen in Indian and Alantic dolphin. It is also known as the Sarawak dolphin. When fully grown it weighs around 200kg and around 2.75m in length. From a distance it can be confused with a striped dolphin which lives in these waters. Usually found in large groups from 100-1000. Below is an encounter between a large group of frasers dolphins and a sailing boat.

While sightings have become far more common in recent times, there is no global estimate for the numbers of this species, though the Southeast Asian species is listed Appendix 2 of CITES so clearly there is a need to keep close watch on this situation.

Indo-Pacific finless porpoise

Indo-Pacific Finless dolphin

 They are found in most of the Indian Ocean, as well as the tropical and subtropical Pacific from Indonesia north to the Taiwan Strait. Overlapping with this species in the Taiwan Strait and replacing it northwards is the East Asian finless porpoise.

They are one of the species protected by the Sundarbans national park, which lies between India and Bangladesh.

Growing to 2.3m at most, and with a weight of up to 72kg (most individuals are far, far, smaller). They eat a wide range of foods from fish and crustations to vegetation such as leaves and rice, and eggs that have been deposited on these leaves.

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