89 Fun Facts About Dolphin

What is a common term for a group of dolphins?

A group of dolphins is a pod; where food is abundant, pods can merge into a superpod of more than 1,000 animals.

For what primary purposes do dolphins use echolocation?

Murky water is no problem: echolocation builds a three-dimensional picture of the surroundings, which dolphins rely on for navigation and hunting, locating prey by listening for echoes.

How do dolphins breathe air?

Dolphins breathe through a blowhole, a single nostril on top of the head, so they can surface with almost none of the body showing; the exhaled spray is most visible in cold air.

Which animal, despite its common name, is the largest species of dolphin?

The orca, or killer whale, is the largest member of the dolphin family Delphinidae; males typically reach 6 to 8 metres, and the longest recorded was about 9.8 metres.

Dolphins are classified as which type of animal?

Dolphins are marine mammals. Like all mammals, they are warm-blooded, breathe air with lungs, give birth to live young, and nurse their offspring with milk.

Approximately how many recognized species of dolphins are there worldwide?

Around 40 dolphin species are recognised, spanning five families: the ocean-going Delphinidae plus river dolphins of South America and South Asia, and the probably extinct baiji.

Roughly how many teeth does a common dolphin carry?

Tooth count runs backwards to body size: the common dolphin, smaller than its bottlenose cousin, carries 188-268 teeth, while the hulking orca makes do with 40 to 56.

The primary diet of most dolphin species consists of which two types of marine life?

Dolphins are carnivores and primarily feed on fish and squid. Their diet can also include other marine invertebrates like octopus and shrimp, depending on the species and habitat.

What unique sleeping method do dolphins employ to remain conscious enough to breathe?

Dolphins utilize unihemispheric slow-wave sleep, meaning one half of their brain sleeps while the other remains awake. This allows them to continue breathing voluntarily and stay aware of their surroundings for safety.

Dolphins killed for meat at Taiji, Japan are caught by what method?

Taiji's fishermen use drive hunting: boats herd a pod toward a cove with banging metal poles and net off the exit; the Faroe Islands and Solomon Islands run similar drives.

Dolphins, whales and porpoises together make up which group?

Cetacea is the infraorder uniting dolphins, whales and porpoises; it splits into baleen whales and toothed whales, and its members live in every ocean and several rivers.

What is it called when travelling dolphins leap clear of the water to save energy?

Porpoising, the series of low leaps made at speed, saves energy because air offers far less drag than water; the jumps also serve for display and to shed parasites.

Unlike most other mammals, dolphins are usually born in what way?

Emerging tail first keeps the newborn from drowning during delivery; the mother then squirts milk into its mouth underwater.

Which land animal is the closest living relative of dolphins?

The hippopotamus is the closest living relative of dolphins and all cetaceans; molecular studies group the two together as Whippomorpha, descended from a semi-aquatic ancestor over 50 million years ago.

The 'wholphin' at Sea Life Park is a cross between a bottlenose dolphin and which species?

Kekaimalu, born at Sea Life Park in 1985, had a false killer whale father and a bottlenose mother; she later produced calves of her own, and wild wholphins have also been reported.

Which cooperative hunting method involves dolphins driving fish onto the shore to catch them?

Strand feeding is seen in bottlenose dolphins of South Carolina and Georgia: they drive fish onto mudbanks, briefly beach themselves to grab them, then slide back into the water.

The 'melon' in a dolphin's head plays a crucial role in which sensory function?

The melon, a fatty organ in the dolphin's forehead, acts as an acoustic lens, focusing the sounds produced for echolocation into a beam.

In Shark Bay, Australia, what do bottlenose dolphins wear on their snouts while rooting through the seabed?

The habit is passed mostly from mothers to daughters, one of the clearest cases of culture and tool use outside primates.

How long can a bottlenose dolphin live in the wild?

Wild bottlenose dolphins can live over 40 years; females typically outlive males by 5 to 10 years, and a few pass 60, though fewer than 2% reach that age.

Which dolphin sound is used mainly for individual identification and long-distance communication?

A signature whistle works like a name: it forms in the first year of life and stays the same for life, and dolphins have recognised the whistles of old companions after 20 years apart.

Which sense is largely absent in dolphins, unlike most land animals?

Dolphins have almost no sense of smell: their brains lack olfactory lobes and nerves entirely, so they rely on hearing and echolocation instead.

What shape are the teeth of most dolphin species?

Look at the teeth to tell them apart: dolphin teeth are conical and pointed for gripping prey that is swallowed whole, while porpoises' are spade-shaped.

How often do dolphins typically renew their outer skin layer?

Dolphins have a remarkably rapid skin renewal process, shedding and replacing their outer skin layer approximately every 2 to 3 hours. This helps maintain their smooth surface for efficient swimming and protects against microorganisms.

The orca, pilot whales and false killer whale are dolphins that are collectively nicknamed what?

'Blackfish' covers six dark-bodied delphinids: the orca, false killer whale, pygmy killer whale, melon-headed whale and both pilot whales, all dolphins despite 'whale' in their common names.

Which of these is the smallest species in the family Delphinidae?

Hector's dolphin is the smallest delphinid: found only around New Zealand, adults are just 1.2 to 1.6 metres long, with a distinctive rounded dorsal fin.

What is a major natural predator of dolphins?

Dolphins fight back: a pod will often mob a great white shark, and for smaller sharks the encounter can prove fatal; bull, dusky and tiger sharks also take dolphins, mostly calves.

What type of social structure do many dolphin species exhibit?

Groups merge and split several times a day, and where food is plentiful they can swell into a superpod of over 1,000 animals.

What is a dolphin's horizontal tail fin called?

There is no bone in it at all: the fluke is the horizontal tail that drives a dolphin forward with an up-and-down beat, unlike a fish's side-to-side tail.

What is the primary purpose of a dolphin's pectoral fins?

A dolphin's pectoral fins, located on its sides, are primarily used for steering, stopping, and maintaining balance in the water.

What is the common name for the dolphin family Delphinidae?

The family Delphinidae encompasses the oceanic dolphins, which are the most diverse and widespread group of dolphins.

Which river dolphin was declared functionally extinct after a 2006 survey found none?

The baiji lived only in China's Yangtze; the boto is the Amazon river dolphin, the susu the Ganges dolphin and the franciscana the La Plata dolphin.

How long is a bottlenose dolphin's pregnancy, on average?

Bottlenose gestation averages about 12 months; births peak in the warmer months and can be attended by a second dolphin acting as a 'midwife', while an orca's pregnancy runs about 17 months.

What is a young dolphin called?

A young dolphin is a calf; bottlenose calves are born about a metre long and nurse for 18 months or more, staying with the mother for several years.

What is a typical cruising speed for a bottlenose dolphin?

Bottlenose dolphins usually cruise at 3-7 mph (5-11 km/h); they can burst to about 18-22 mph, but only briefly, while orcas can hit roughly 34 mph.

Which physical adaptation allows dolphins to maintain their body temperature in cold ocean waters?

A thick layer of blubber insulates dolphins against cold water; it also stores energy for lean times and, in bottlenose dolphins, makes up 18 to 20% of body weight.

What kind of vision do dolphins typically have underwater?

The retina has both rods and cones, and at the surface the lens and cornea correct for the nearsightedness caused by water; eyes on the sides of the head give two visual fields rather than one.

A single blowhole on top of the head places dolphins in which group?

Baleen whales keep two openings; the single one lets toothed whales such as dolphins vent air in a fast upward blast before diving again.

Which kind of dolphin grouping tends to last the longest?

Pairs of males have been tracked together for 20 years; in Shark Bay, alliances of males herd a female for weeks and fight rival alliances for her.

What is a dolphin doing when it 'rakes'?

The parallel scars are so characteristic that researchers count them to measure how much aggression a population sees; adult males carry the most.

Dolphins descend from land-dwelling animals of which order?

Dolphins belong to Artiodactyla, the even-toed ungulates; they split from Indohyus, a chevrotain-like relative, about 48 million years ago.

What sounds do dolphins make in close-quarters interactions like fighting or excitement?

Burst pulses, rapid trains of clicks heard as squawks or barks, mark close-quarters aggression and excitement; when two dolphins converge on the same fish, the less dominant one usually backs off.

How do scientists primarily determine the age of a dolphin?

The layers work like tree rings, though the method is now thought to undercount in older animals.

Which of these is not a common characteristic of dolphin skin?

Newborns do carry a single band of whiskers along each side of the snout, which soon fall out; the epidermis is otherwise hairless and glandless apart from mammary glands.

The frequency range of sounds produced by bottlenose dolphins, including those for echolocation and communication, can extend into what range?

Bottlenose clicks are ultrasonic: echolocation clicks peak around 40 to 130 kHz, several times above the 20 kHz ceiling of human hearing, while whistles sit mostly within our range.

Instead of an outer ear, dolphins mainly receive sound through what part of the body?

Sound enters mainly through the lower jaw and throat region, where a fat-filled channel conducts it to the inner ear; air-filled sinuses isolate the ear from the skull so the dolphin can tell direction.

What is the common name of the species Delphinus delphis?

Delphinus delphis is the short-beaked common dolphin, one of the most abundant cetaceans, travelling in schools of hundreds in warm-temperate and tropical seas.

Which species is the largest of the river dolphins?

The Amazon river dolphin, or boto, is the largest river dolphin: males reach about 2.5 metres and 185 kg, far bigger than the Ganges or La Plata dolphins.

Dolphins get most of their fresh water from what?

Dolphins get fresh water mainly from the fish and squid they eat, plus water released by metabolising fat; their kidneys concentrate urine so they need not drink seawater.

What is the scientific term for a dolphin's beak-like snout?

The rostrum is the elongated jaw that forms a dolphin's beak; bottlenose dolphins take their name from its short, stubby shape, while common dolphins carry a long slender one.

The bottlenose dolphin belongs to which genus?

Tursiops truncatus is the common bottlenose dolphin; the genus name joins Latin tursio, a dolphin-like fish in Pliny, with Greek ops, 'appearance'.

What is the muscular tail stock between a dolphin's body and its flukes called?

The peduncle, or tail stock, is the muscular section between the body and the flukes; its powerful muscles drive the up-and-down beat that propels a dolphin.

What is an adult male dolphin called?

Females are cows, and a group can be called a school as well as a pod.

Which fish, popular on restaurant menus, is confusingly known as the dolphinfish?

Mahi-mahi, Coryphaena hippurus, is the dolphinfish, a ray-finned fish unrelated to the mammal; menus use the Hawaiian name so diners do not think they are eating dolphin.

Which title was borne by the heir apparent to the French throne?

The Dauphin took his title from the dolphin on the arms of the Dauphiné, ceded to the French crown in 1349 on condition that the heir bear its name.

In Greek legend, a dolphin rescued which poet from drowning and carried him to Cape Matapan?

Arion of Lesbos, in Herodotus' account, leapt overboard to escape murderous sailors and was carried ashore at Cape Taenarum (Matapan); a bronze of Arion on a dolphin stood there.

India named its national aquatic animal in a bid to protect which endangered species?

The Vikramshila Gangetic Dolphin Sanctuary was created on the river for the animals, which Hindu myth links to the goddess Ganga.

Which Greek god turned a crew of Etruscan pirates into dolphins after they tried to ransom him?

Dionysus, as Apollodorus tells it, turned the mast and oars into serpents and filled the ship with ivy; the terrified Tyrrhenian pirates leapt overboard and became dolphins.

Cooked dolphin meat, as eaten in Japan, is said to taste most like what?

Dolphin meat is so dark red it looks almost black; cooked, it is usually compared to beef liver, and raw it is served as sashimi with onion and horseradish or garlic.

Which rescued female began the tail-walking craze among Port River dolphins near Adelaide in 1988?

Billie, freed from a marina lock in 1988, spent weeks recovering at a marine park alongside trained dolphins and came back tail-walking; Wave and other Port River females copied her.

Which ancient whale of about 43 million years ago is linked to the first tail flukes?

Nostrils migrated to the top of the skull and forelimbs became flippers later, with Basilosaurus around 35 million years ago.

On the 1960s TV series Flipper, the dolphin's 'voice' was really the call of which bird?

The dolphin's 'voice' was a doctored kookaburra call; Flipper was played by five female dolphins chosen for their unscarred skin, with a male named Clown brought in for one trick.

The original Flipper TV series (1964–67) aired on which US network?

Flipper aired on NBC from September 1964 to April 1967, filmed at the Miami Seaquarium, whose lagoon went on to host a Flipper Show for decades.

Fungie, a lone wild dolphin who sought out people for 37 years, lived in which country?

Fungie lived in Dingle harbour, County Kerry, Ireland, from 1983; Guinness World Records declared him the world's oldest solitary wild dolphin before he vanished in October 2020.

Pelorus Jack escorted ships for 24 years through which dangerous New Zealand channel?

Pelorus Jack met ships at French Pass, between D'Urville Island and the South Island, from 1888 to 1912; after someone shot at him in 1904 he was protected by law.

Since 1989, Pelorus Jack has featured in the livery of which New Zealand service?

The Interislander Cook Strait ferries have carried a Pelorus Jack dolphin emblem since 1989; the original was a Risso's dolphin, white-headed with age.

Opo, the dolphin who played with children at Opononi, died in 1956 one day after what?

Opo died on 9 March 1956, a day after legal protection for her became law under an Order in Council; she was buried with full Maori honours beside Opononi's war memorial hall.

Winter, the dolphin with a prosthetic tail, lived at an aquarium in which Florida city?

Winter lived at the Clearwater Marine Aquarium from 2005 until her death in 2021; the gel sleeve designed for her tail was later adapted to ease prosthetic limbs for human amputees.

Winter, the dolphin whose prosthetic tail inspired the film Dolphin Tale, lost her tail in 2005 after becoming tangled in what?

The rope cut off the blood supply: a crab trap line wrapped Winter's tail, and without flukes she swam side to side like a fish, which threatened her spine.

Adult Amazon river dolphins, or botos, are famous for turning what colour, most strongly in battle-scarred males?

Every scrape makes them rosier: adult botos turn pink from repeated skin abrasion, so the most battle-scarred males are the brightest, which earned the 'pink river dolphin' nickname.

The Amazon river dolphin can turn its head 90 degrees because which bones are unfused?

Unlike most dolphins, the boto's neck vertebrae are unfused, so it can turn its head 90 degrees to thread through flooded forest, where it hunts more than 50 fish species including piranhas.

In Amazon folklore, the river dolphin is an 'encantado' that appears at night as what?

The boto encantado is said to come ashore at night as a handsome young man in a white hat that hides his blowhole; local legend warns that eye contact brings lifelong nightmares.

Irrawaddy dolphins are popular in aquarium shows partly for which unusual habit?

Their name comes from Myanmar's Ayeyarwady River, where wild ones herd fish into fishers' cast nets in exchange for a share of the catch.

The critically endangered Maui dolphin is found only off which coast?

Maui dolphins live only off the west coast of New Zealand's North Island; post-mortems found toxoplasmosis, a parasite spread by cats, among the confirmed causes of death.

Philibert Commerson first described his namesake dolphin in 1767 in which waterway?

Commerson saw the dolphins in the Strait of Magellan in 1767 while sailing with Bougainville's expedition; the sharp black-and-white pattern earned it the nicknames panda dolphin and skunk dolphin.

The hourglass dolphin was accepted as a species in 1824 on the strength of what alone?

Quoy and Gaimard named the hourglass dolphin in 1824 from a drawing made at sea, with no specimen in hand; whalers called the Antarctic dolphin a 'sea skunk', and cruciger means cross-bearer.

Risso's dolphins usually have just two to seven pairs of teeth, all located where?

Risso's dolphins carry their two to seven pairs of peg-like teeth only in the lower jaw, suited to a diet almost entirely of squid; older animals are so scarred they look nearly white.

How many spins can a spinner dolphin make during a single leap?

A spinner dolphin can rotate up to seven times in a single leap; scientists think the spins may send acoustic signals to the pod or shake off hitchhiking remoras.

Purse-seine fishing for which fish killed tens of thousands of spinner dolphins?

Tuna purse seines in the eastern tropical Pacific killed huge numbers of spinner and spotted dolphins, which school above yellowfin tuna; the outcry produced the 'dolphin safe' label in 1990.

The US Navy's Marine Mammal Program trains its dolphins in the bay of which city?

The Navy Marine Mammal Program is based at Point Loma on San Diego Bay; its dolphins sweep for sea mines and mark intruding divers, and the Navy says they are never trained to attack.

In 1965, Navy dolphin Tuffy ferried tools to divers in which undersea habitat?

SEALAB II sat about 205 feet down off La Jolla in 1965; Tuffy carried tools and mail between the surface and the habitat and was trained to guide lost divers back to safety.

In the 2003 Iraq War, US Navy dolphins helped find more than 100 mines at which port?

Navy dolphins swept the approaches to Umm Qasr in March 2003, finding more than 100 mines so the port could reopen for aid ships; the program, secret since 1967, was declassified in 1992.

In 2022, which dolphins were filmed rubbing on Red Sea corals, apparently to treat their skin?

A 2022 study in the Red Sea filmed Indo-Pacific bottlenose dolphins queuing to rub against gorgonian corals and sponges whose mucus carries antibacterial compounds, apparently as skin care.

In the constellation Delphinus, the star names Sualocin and Rotanev spell what backwards?

Nicolaus Venator is the Latinised name of Niccolo Cacciatore, a director of Palermo Observatory who slipped himself into the sky.

The Cove, a 2009 documentary on the Taiji dolphin hunt, won which honour in 2010?

The Cove won the Academy Award for Best Documentary Feature at the March 2010 ceremony; parts were shot in secret with high-definition cameras disguised as rocks.

Dolphin-communication researcher John C. Lilly is also credited with inventing what?

Lilly built the first isolation tank in 1954 while at the NIH; he later flooded part of a Virgin Islands lab so a human and a dolphin could live together, and his work inspired Altered States.

The word 'dolphin' traces back to a Greek word related to which body part?

So the animal's name roughly means 'fish with a womb'; an old English alternative was 'mereswine', or sea pig.

How does a bottlenose dolphin's brain weight compare with a human's?

Bigger than ours, if only just: at 1,500–1,700 grams a bottlenose brain is slightly heavier than a human's 1,300–1,400 grams and about four times a chimpanzee's 400.

In Laguna, wild dolphins have signalled fishermen when to cast their nets since before 1847; which country is that in?

Nobody trained them: the partnership in Laguna, Santa Catarina, Brazil, dates from before 1847, and Pliny the Elder described the same kind of cooperation in Roman times.

Dusky dolphin groups off Kaikoura, New Zealand, can swell to roughly how many animals?

Off Kaikoura, dusky dolphin groups swell to about 1,000 animals in summer, splitting into smaller foraging and nursery groups by day; the species is among the most acrobatic, famed for somersaults.