Frequently Asked Questions about Facts about whales and dolphins | WDC Home › Frequently Asked Questions › Frequently Asked Questions about Facts about whales and dolphins Frequently Asked Questions about Facts about whales and dolphins What are the differences between whales, dolphins and porpoises? Collectively, whales, dolphins and porpoises are known as cetaceans. Cetacean species are divided into two groups; (1) Baleen whales – these are the “great whales” and as their name suggests they all have baleen plates that are used to filter their food (which consists of plankton and small species of fish). (2) Toothed whales (otherwise known as odontocetes and including all species of dolphin and porpoise) – which as you would expect, have teeth, and eat larger prey items, including at times, other marine mammals. The main differences with porpoises are that they are usually smaller than other toothed whales and instead of cone-shaped teeth they have flat, spade-shaped teeth. As a general rule of thumb, baleen whales are larger (except the sperm whale ), and slower (except the fin whale which is known as the “greyhound of the sea”) than toothed whales.

Additionally, ALL baleen whales have two blowholes, whilst toothed whales only have one. Humpback whale Vanessa Mignon (3) Difference between a dolphin and a porpoise. The biggest difference is size, with all species of porpoise being that much smaller than their dolphin cousins. Porpoises don't have the pronounced beak that most, but not all dolphins have and they also have a different teeth shape. Porpoise teeth are spade-shaped whilst dolphins are conical. Harbour porpoise © Charlie Phillips Charlie Phillips/WDC A dolphin has a hooked or curved dorsal fin (except for those species that don't have a dorsal fin) whereas a porpoise has a more triangular dorsal fin, and generally speaking, dolphin bodies are leaner, whilst porpoises’ are a little more chunky. Dolphins are also more "talkative" than porpoises. The whistles made by dolphins are produced through their blowholes and whilst porpoises do not do this, possibly due to structural differences in the porpoise’s blowhole, they can still be pretty noisy as they "puff" the air out when they surface.

Short-beaked common dolphin Tim Stenton Dolphins and porpoises also have many similarities, one of which is their extreme intelligence. As research evolves, it is likely that more (or perhaps fewer) differences between dolphins and porpoises will be revealed. More facts about whales and dolphins or have a look in our whale and dolphin species guide . How many species of whales, dolphins and porpoises are there? There are currently 89 species of whales, dolphins and porpoises. This is composed of 14 species of mysticetes (otherwise known as baleen whales) and 75 species of odontocetes (otherwise known as toothed whales and includes all species of dolphin and porpoise). If however you were to include sub-species and sub-populations then that figure would rise to 118. Find out more in our species guide . How do whales, dolphins and porpoises communicate with each other? Communication amongst whales and dolphins is achieved in several ways. They create sounds, make physical contact and use body language. Large whales can communicate over huge distances (across entire ocean basins) using very low frequencies.

Dolphins and porpoises however, usually use higher frequencies, which limits the distance their sounds can travel. In general, dolphins make two kinds of sounds, “whistles” and “clicks”. Clicks are used to sense their surroundings through echolocation, while they use whistles to communicate with other members of their species and very likely, with other species too. It is also thought that each dolphin has a unique whistle called a ‘signature whistle’, which is used to identify an individual. What are the different fins on a dolphin used for? The tail fin, or fluke, is used for propulsion through the water. The pectoral fins (on each side) provide directional control and the dorsal fin (in those species that have one) provides stability whilst swimming. Many individuals however have been documented without a “complete set” of fins (likely as a result of incidental entanglement in fishing gear, being hit by a boat’s propeller or a lucky escape from a predator) and therefore they can sometimes adapt quite well to losing part or all of a fin. Dolphin illustration More facts about whales and dolphins . How do dolphins “see” underwater?

As well as having extremely good eyesight (except the river dolphins who are bordering on being blind) that allows them to see both above and below the water, toothed whales use a sense called echolocation to navigate and hunt underwater. This means that they emit sound waves and then detect and interpret the echoes that bounce back off of other creatures and objects in the water around them, allowing them to build up a picture of their surroundings. More facts about whales and dolphins . How do whales, dolphins and porpoises hear? Whales do not have ears on the outsides of their heads. Instead, they generally hear sounds through special structures in their jawbones. More facts about whales and dolphins . Do whales, dolphins and porpoises have a sense of smell? No – they lack an olfactory nerve and associated lobes and therefore it is believed that they have no sense of smell. They do however have a keen sense of taste, showing a preference for specific types of fish and seafood. More facts about whales and dolphins . What do dolphins eat? Dolphins are carnivores; they eat other animals. Dolphins eat a variety of fish, squid, shrimps, jellyfish and octopuses.

The types of fish and other creatures dolphins eat depends on the species of dolphin, where the dolphins live and the wildlife that shares their habitats. There are more than forty species of dolphin and they live in environments ranging from fresh water rivers, estuaries, coastal waters to deep sea open oceans. Most dolphins are opportunistic feeders, which means they eat the fish and other animals sharing their homes. All dolphins eat fish and those living in deep oceans also eat squid and jellyfish. Bottlenose dolphins are found worldwide in temperate and tropical seas and the types of fish they eat, is dependent on where they live and what time of year it is. Bottlenose dolphins living in the Moray Firth, Scotland, favour salmon when it is available in the spring and summer months. In the winter, salmon is scarce, and so they eat herring and mackerel. Bottlenose dolphins living elsewhere eat their favoured local fish which can be mullet, mackerel, catfish and more tropical species of fish. All dolphins have teeth but they don't chew their food, they just, grab, bite and swallow!

Amazon river dolphins are known to eat more than 40 different species of fresh water fish and they also eat fresh water crustaceans. Spinner dolphins eat fish, jellyfish and krill. Dusky dolphins eat shrimp, squid and various fish, including tiny anchovies. Rough-toothed dolphins live in deep water oceans and eat mostly squid. Commerson’s dolphins feed on small fish, crabs, octopus, and small crustaceans in kelp beds close to shore and near the seabed. New Zealand dolphins feed on species of small fish and squid in shallow coastal waters. Orcas are the biggest members of the dolphin family; resident orcas in Northern British Columbia, Canada eat only fish – their favourite is salmon. Other orcas specialise in eating much bigger prey including seabirds and mammals such as sea lions, dolphins and whales. Orca diet depends on what food is available to them where they live and what techniques they have learnt from their elders to hunt their food. Dolphins hunt using their highly-developed echolocation , which means they can find food no matter how murky the water might be. Not only that but they can even use it to identify any prey that might be hiding, such as under the sand!

What do dolphins drink? Dolphins get all the water they need directly from the food they eat. Their main prey (fish and squid) contains large amounts of water. Dolphins don’t lose water by sweating, like we do, and so they need less water than us in their diets. More facts about whales and dolphins . Bottlenose dolphin Zephyr with salmon Charlie Phillips/WDC How do dolphins sleep? Dolphins sleep in a very different way to the way we humans do. Humans have prolonged periods of unconscious sleep and we are not aware of our surroundings for periods of time while sleeping. Humans have a breathing reflex and when we sleep or become unconscious, we continue to breath automatically. Dolphins cannot sleep in this way, they have to remain conscious, even when they are sleeping. This is because their breathing is not automatic, it is consciously controlled. In other words dolphins have to actively decide when to breath, and so they must be continually conscious to breath. If like us, dolphins went into a deep unconscious sleep, they would stop breathing and suffocate or drown.

To get around this, dolphins only allow one half of their brains to sleep at a time; the other half stays alert to enable the dolphin to continue breathing and look out for dangers in the environment. Dolphins only close one eye when they sleep; the left eye will be closed when the right half of the brain sleeps, and vice versa. This type of sleep is known as unihemispheric sleep as only one brain hemisphere sleeps at a time. Dolphins alternate which side is sleeping periodically so that they can get the rest they need without ever losing consciousness. When sleeping, dolphins often rest motionless at the surface of the water, breathing regularly or they may swim very slowly and steadily, close to the surface. In shallow water, dolphins sometimes sleep on the seabed rising regularly to the surface to breath. More facts about whales and dolphins . Atlantic white-sided dolphin WDC/Anja Reckendorf Do whales and dolphins sneeze? No - A whale or dolphin already exhales far faster than humans and other land mammals do. A human sneeze is about 100 mph ... whales are even faster than that at their normal breathing rate ...

so it's possible that they have no "need" for sneezing in the traditional sense. More facts about whales and dolphins . Do whales, dolphins and porpoises have hair? All mammals have hair at some point in their life and cetaceans are no exception. Although lost before or shortly after birth, tiny hairs are found around the tip of the rostrum. The only exception to this is the boto, which doesn’t lose these hairs and maintains them throughout its life. More facts about whales and dolphins . What is baleen? Baleen is made out of keratin, the same protein that makes up our fingernails and hair. A baleen whale, such as the humpback whale below, has about 600 baleen plates in its upper jaw, which act like a strainer as it feeds. Like humans, whales cannot drink saltwater. Hairs on the baleen plates catch the fish or plankton, while the saltwater washes through and goes back into the ocean. Some whales eat about one ton (2,000 lbs.) of fish each day. That’s the weight of a large car!

You can tell if you see a baleen whale by their blowholes. All baleen whales have two blowholes visible on the top of their heads. More facts about whales and dolphins . How do dolphins breathe? Dolphins are mammals and breathe air into their lungs, just like we do. Dolphins cannot breathe under water like fish can as they do not have gills. Dolphins breathe through a nostril, called a blowhole, located right on top of their heads. This allows them to take breaths by exposing just the top of their heads to the air while they are swimming or resting under the water. After each breath, the blowhole is sealed tightly by strong muscles that surround it, so that water cannot get into the dolphin’s lungs. When a dolphin surfaces for air, he breathes out (exhales) first and then breathes in (inhales) fresh air; it only takes a fraction of a second for the dolphin to do this. If you are close by, it is easy to hear a dolphin’s ‘blow’ at the surface; in fact you will often hear a dolphin before you see him!

The blow is the sound you hear, and the spray of water you see, when the dolphin forcefully breathes out and clears away any water resting on top of his blowhole. The water spray is not coming from the dolphin’s lungs; it is just water sitting on top of its head around the blowhole being blown away before he inhales. Dolphins do not breathe through their mouths in the same way as people can, they only breathe through their blowholes. In this way, breathing and eating are kept entirely separate in dolphins so that they can capture prey in their mouths and swallow it without the risk water getting into their lungs. However, in 2016 a paper was published that reported on a dolphin that had learnt to breathe through its mouth . Dolphins are able to hold their breath for several minutes but typically they breathe about 4 or 5 times every minute. Bottlenose dolphin at surface Sign up for email updates Adopt a whale ODFW, Oregon Wildlife Species: Whale, dolphin and porpoise Oregon Wildlife Species Mammals: Whale, dolphin and porpoise Oregon Mammals: -Wikipedia- Gray Whale Eschrichtius robustus The most common whale off the Oregon coast is the gray whale.

In addition to the approximately 200 resident gray whales that live nearly year round off Oregon, a winter and spring migration brings about 18,000 gray whales past our coast. Gray whales are baleen whales (mysticetes). They grow to 50 feet in length and will weigh up to 80,000 pounds; adult females are larger than males, which is common in all baleen whales. They do not have a dorsal fin on their back but instead have a series of knuckles.These whales are mottled gray and are covered with barnacles and whale lice. Newborn calves are about 15 feet long when born and are dark gray in color. The height of the winter migration off Oregon is usually between Christmas and New Year’s Day. The Whale Watch Center in Depoe Bay reports sightings of as many as 50 whales per day moving south to their breeding grounds in the Sea of Cortez during Whale Watch Week. Those numbers decline but remain strong through January. In general during the winter months whales are further offshore and more difficult to see from headlands.

Oregon State Parks has a program called Whale Watching Spoken Here where volunteer observers are at most outlooks during winter and spring breaks. Tagging studies by Oregon State University scientists show that most gray whales only stay about three weeks in the warm waters off Baja, Mexico. Then they head back to the cold, but plankton-rich waters of the north Pacific. The female gray whales with calves stay on the breeding grounds an additional month or two. Their return to northern waters in April is slower and usually closer to land. This gives whale calves a break and whale watchers their best opportunity to see the whales. To watch the migration, it is best to pick a calm morning and find a view point that is high enough to spot the spouts. Learning good binocular technique will help spot the whales. Gaze out onto the ocean, focusing on medium distances until you see a puff of white. Then raise your binoculars while continuing to look at the place you saw the blow. This technique takes some practice, but generally works best when trying to spot whales. When warm, moist air exhaled from the animals' lungs meets the cool air at the ocean surface, it creates the bushy column called a blow or spout. Each whale species has a distinct blow.

A gray whale's blow is up to 15 feet high and is visible for about five seconds on a calm day. The whale will dive for three to six minutes, then surface for three to five blows in row, 30 to 50 seconds apart, before diving deep for three to six minutes again. Generally in winter, the animal will move to your left (south) and during spring will be heading right (north). Sometimes you can see a muddy streak in the water that surfaces as the whale churns up the ocean floor for food. The whales tail, or fluke, moving just below the surface can create a whale "footprint" a round, smooth spot in the water. Gray whales are the most coastal of the baleen whales and are often found within a few miles of shore as they migrate from Alaska to Baja. Gray whales have baleen instead of teeth. To feed, they fill their vast mouths with mud from the sea bottom and strain it through their baleen to capture amphipods and other small animals. This is the only type of whale to feed in this manner.

Grays are amazing in their capacity to feed in variety of ways including taking fish or mysid shrimp directly from the water column and straining food off kelp as well. Whales - Balaenopteridae Family -NOAA- Blue Whale Balaenoptera musculus Blue whales are occasionally spotted off Oregon, but usually no closer than 10 miles offshore. These whales are part of the Eastern North Pacific population that range from Alaska to Costa Rica. They migrate between feeding areas along the west coast of the United States and Canada and breeding and calving grounds off Mexico and Central America. They are thought to be among the most endangered of the great whales. Whale watching center, Oregon State Parks , Blue whale research, OSU Minke Whale -NOAA- Minke Whale Balaenoptera acutorostrata The minke whale is one of the smallest baleen whales, growing to about 35 feet. They feed along the coast in the same area as gray whales. It is close enough in size to a gray whale that you could mistake one from the other at a distance. At close range, however, the difference is apparent. Minke’s have a dark black or gray, sleek body with white underside.

They are often recognized by surfacing snout first and a small, weak, but visible, bushy blow that is about 6 to 10 feet high. When diving they do not display their flukes. On the surface they have a quick fluid movement, which creates spray (sometimes described as a rooster tail) when traveling at high speeds. Before deep dives, they may arch and expose much of their back and body during high rolls above the surface. These whales are capable of diving for at least 15 minutes, but regularly submerge for 6-12 minutes at a time. Minke whales are often active at the surface and are commonly seen breaching. Humpback Whale -Wikipedia- Humpback Whale Megaptera novaeangliae Humpback whales are seen during their north and south migrations from northern waters to breeding grounds near Hawaii and also feeding offshore during the summer. Humpbacks have been documented travelling 3,000 miles between Alaska and Hawaii in as few as 36 days. They are usually five to 15 miles offshore, so they are most often seen by fishers. Humpback whales live in all major oceans from the equator to sub-polar latitudes.

Humpbacks eat primarily krill and small fish and can consume 3,000 pounds of food a day. Humpbacks grow to 60 feet in length with a stocky body, an obvious hump, a knobby head and unusually long pectoral fins, which can measure up to 15 feet. The tail, which it lifts above the surface of the water in some dives, has a wavy trailing edge and black and white markings that are unique to individuals. Scientists can identify individual whales by photographs of the underside of flukes, much like a detective can identify someone by their fingerprints. Considered the acrobats of the sea, humpbacks often breach and slap the water with their tail and pectorals. They are also known for their beautiful "songs," which, although studied for years, are not well understood. Whales - Physeterdae Family -Photo by Greg Gillson- Sperm Whale Physeter catodon Sperm whales inhabit all oceans of the world, and have been observed in Oregon waters from March through November. Sperm whales are usually found in deep off-shore waters so they are only occasionally seen off Oregon by fishers and birders on offshore trips.

It is the largest of the toothed whales. It possesses the largest brain of any animal and an enormous head to house it. Sperm whales have 20 to 26 large conical teeth found only in their lower jaw. A mature male can grow to 52 feet long with its head representing up to one-third of its length. It is also the largest living toothed animal, feeding on giant squid, sharks, rays and fishes. Plunging to 9,800 feet for prey, it is the deepest diving mammal. Its clicking vocalization, a form of sonar, is the loudest sound produced by any animal. The blow is a noisy, single stream that rises up to seven feet or more above the surface and points forward at a 45-degree angle since the blocky head is asymmetrical and the blow hole is located on the left side near the tip. The sperm whale's flukes are triangular and very thick. The whale lifts its flukes high out of the water as it begins a feeding dive. It has a series of ridges on the back's caudal third instead of a dorsal fin.

The largest ridge was called the 'hump' by whalers, and can be mistaken for a dorsal fin because of its shape and size. In contrast to the smooth skin of most large whales, a sperm whale’s black skin is wrinkly like a prune. Sperm whales were a prized catch for whalers in the 1800s for the rich waxy substance found in their heads called spermaceti. Spermaceti was used to make smokeless candles, soap, cosmetics and lamp fuel. In the mid-1800s it is estimated that whalers killed perhaps 5,000 sperm whales each year. Dolphins, Porpois, Killer Whales - Delphinidae Family Pacific Whitesided Dolphin -NOAA- Pacific Whitesided Dolphin Lagenorhynchus obliquidens The Pacific white-sided dolphin are most abundant in the Southern California Bight in winter, but move further north, off Oregon and Washington in summer. These animals can be found from tip of Baja to the Aleutians and the western Pacific from the Kuril Islands to Japan. They prefer deep, off-shore waters, so sighting are usually limited to recreational and commercial fishers.

The Pacific white-sided dolphin is about seven or eight feet long. It has three colors: the chin, throat and belly are creamy white; the beak, flippers, back, and dorsal fin are a dark gray, and there are light gray patches on the sides and a further light gray stripe running from above the eye to below the dorsal fin where it thickens along the tail stock. It also has a dark gray ring surrounding the eyes. The Pacific white-sided dolphin is extremely active and mixes with many of the other north Pacific cetacean species. It readily approaches boats and rides on bow waves. Large groups are common; averaging 90 individuals, with super groups that can number more than 300. They mainly eat hake, anchovies, squid, herring, salmon and cod. Bottlenose Dolphin -Wikipedia- Bottlenose Dolphin Tursiops The bottlenose dolphin is the most common of the oceanic dolphins and can be found in all tropical and temperate oceans. Flipper was a bottlenose dolphin. Their considerable intelligence and permanently-affixed smile make them a favorite of aquarium and television shows. The U.S. Navy also uses bottlenose dolphins to find mines and booby traps underwater.

Oregon is the northern extent of its range on the West Coast. They are most often seen offshore during the summer by tuna and other fishers. They are gray with light gray to white on the undersides. In size they range from six to 13 feet in length and can weigh up to 650 pounds. Bottlenose dolphins typically live in pods of 10 to 30 individuals, but group size varies from single individuals up to more than 1,000. They mainly eat forage fish and often work as a team to harvest fish schools. Dall Porpoise -Wikipedia- Dall Porpoise Phocoenoides dalli A thick body, small head and coloration similar to a killer whale make this dolphin easy to recognize. Dall’s porpoise is mostly black with a large white patch on the belly and flanks. The small dorsal fin is partly white and the trailing edges of the tail are frosted white. About seven feet long and weighing around 400 pounds, Dall’s live only in the north Pacific.

Dall’s are the fastest of all small cetaceans and can swim at up to 35 miles per hour, almost as fast as a killer whale. When swimming at the surface they create a characteristic "rooster tail." They often ride on the bow wave of boats, but lose interest if the boat isn’t going fast enough. They prefer deep water, so they are not often seen close to land. Each year about 15,000 Dall’s porpoise are killed by Japanese fishers, making it the largest direct hunt of any cetacean species in the world. Harbor Porpoise -Wikipedia- Harbor Porpoise Phocoena phocoena Like the name suggests, harbor porpoise remain close to shore and in river estuaries and bays usually less than 650 feet deep. This makes them the most likely porpoise seen from shore. They seem more shy than their larger, more gregarious cousins, like the Dall’s porpoise or bottlenose dolphin. You won’t see them riding the bow waves of boats. They are also not as social, usually seen alone or in small groups of two or three, rarely more than five individuals.

Found throughout the temperate coastal waters of the Northern Hemisphere, harbor porpoise are the smallest of the northern Pacific cetaceans growing to five feet and weighing up to 165 pounds. They are dark gray to black with light gray undersides. They have a blunt, rounded head and small black mouth with inward-curving lips. They usually stay near the surface, coming up about every 25 seconds to breathe with a distinctive puffing noise that sounds like a sneeze. Harbor porpoise eat small forage fish, like sardines and herring. They, in turn, are food for great white sharks and killer whales. Killer Whales -Wikipedia- Killer Whale Orcinus orca Seeing killer whales off the Oregon coast is a rare treat, but whale watchers can usually count on a pod of orca’s patrolling the coast inmid April – just in time to intercept baby gray whales. Orcas are most often seen in the ocean off Depoe Bay and Newport, but can be spotted coast wide. The first thing you are likely to see when sighting killer whales is their dorsal fin. Male orcas have a dorsal fin that can be six feet in height, juveniles and females have shorter fins.

These large fins can be seen from quite a distance. There are three distinct types of killer whales: residents, transients and offshores. Each differs in morphology, ecology, behavior and genetics. All three have overlapping ranges so any type could be seen in Oregon waters. In general resident whales are the most studied. They are found in large pods (groups) and eat primarily fish. Transient whales have been studied in coastal waters and stay in smaller pods generally made up of less than 10 whales and eat primarily marine mammals. Offshores have the largest geographic range and are generally found at least nine miles offshore. They eat primarily fish. Several times in recent years orcas came into Yaquina Bay in Newport attracted by the proliferation of seals and sea lions. Some years, they linger at the edges of the bay's jetties. A few years ago many people watched as a killer whale chased a sea lion all the way through Yaquina Bay, almost as far east as Toledo. The orcas usually only stay a couple of weeks, but in 2006, the killer whales lingered until the middle of July. The Whale Watch Center receives an average of 30 reports of orca sightings a year.

To catch sight of Oregon’s visiting killer whales is just like spotting any whale, you need patience and a high vantage point. The Newport area has many of these, such as the lighthouse at Yaquina Bay, the Yaquina Head area, Don Davis Memorial Park in Nye Beach and nearby at Cape Foulweather. The headquarters for the Whale Watch Spoken Here program is at the seawall in Depoe Bay and is another good place to spot orcas. Dolphin | Article about dolphin by The Free Dictionary Dolphin | Article about dolphin by The Free Dictionary Also found in: Dictionary , Thesaurus , Medical , Idioms , Wikipedia . dolphin, large, swift game fish, Coryphaena hippurus, also called dorado. It is of nearly worldwide distribution in warm waters. Its long, slender body is blue, and in the living animal there are luminous shades of gold, green, and purple. The dolphin has a dorsal fin that runs the length of the body and a forked tail. Males, larger than females, may reach a length of nearly 6 ft (1.8 m) and a weight of over 65 lb (30 kg).

Dolphins travel alone or in groups, attaining speeds of 35 mi (56 km) per hr. They feed on a variety of fishes, especially flying fish, which they sometimes pursue by leaping out of the water. They are valued as food in Polynesia, where they are known as mahimahi. The term dolphin is also applied to a group of aquatic mammals (see dolphin dolphin, aquatic mammal, any of the small toothed whales of the family Delphinidae, numbering more than 50 species. These include the true, or beaked, dolphins, the killer whale, the pilot whale, and 12 freshwater species found in rivers of South America and S and E Asia. ..... Click the link for more information. , mammal). The fish known as dolphins are classified in the phylum Chordata Chordata , phylum of animals having a notochord, or dorsal stiffening rod, as the chief internal skeletal support at some stage of their development. Most chordates are vertebrates (animals with backbones), but the phylum also includes some small marine invertebrate animals. ..... Click the link for more information.

, subphylum Vertebrata, class Actinopterygii, order Perciformes, family Coryphaenidae. dolphin, aquatic mammal, any of the small toothed whales whale, aquatic mammal of the order Cetacea, found in all oceans of the world. Members of this order vary greatly in size and include the largest animals that have ever lived. Cetaceans never leave the water, even to give birth. ..... Click the link for more information. of the family Delphinidae, numbering more than 50 species. These include the true, or beaked, dolphins, the killer whale killer whale, orca, or grampus, a large, rapacious marine mammal of the dolphin family. Historically considered one species, Orcinus orca, ..... Click the link for more information. , the pilot whale, and 12 freshwater species found in rivers of South America and S and E Asia. Most species are highly gregarious. The name dolphin, meaning "beaked," is also applied to a species of fish (see dolphin dolphin, large, swift game fish, Coryphaena hippurus, also called dorado. It is of nearly worldwide distribution in warm waters.

Its long, slender body is blue, and in the living animal there are luminous shades of gold, green, and purple. ..... Click the link for more information. , fish). In the United States dolphins are often mistakenly called porpoises, a name correctly applied to small, blunt-nosed whales of another family. Until recently dolphins formed the basis of a widespread fishing industry; only the Japanese continue to hunt them for food on a large scale. They are accidentally caught and killed in large numbers in tuna seining operations. Characteristics and Species Dolphins are fishlike in form, with streamlined, hairless bodies. Their powerful, horizontal flukes, or tail fins, drive them through or out of the water, while their forefins and dorsal fin are used for steering. Constantly shedding their skins, dolphins accumulate no barnacles or other external parasites. A layer of blubber protects them from cold and seals small wounds. Dolphins breathe air through a single, dorsal blowhole.

The dolphin's intelligence, playfulness, and friendliness, its built-in smile and merry-looking eyes have been a source of interest and enchantment to human beings from earliest times; it is a common figure in mythology and literature and has been much depicted in art, especially in the posture of its graceful, arched, 30-ft (9-m) leap. Dolphins have long been famous for riding the bows of ships, and it is now known that they also ride the bows of large whales. Today they are valued and exploited as entertainers in more than 40 water shows around the world and have thus become available for extensive study. The best known species are the common dolphin (Delphinus delphis), of worldwide distribution, and the bottle-nosed dolphin (Tursiops truncatus), found in coastal waters of the North Atlantic Ocean and the Mediterranean Sea. The bottlenose has been particularly intensively studied; it is presumed that much of what is known about this species applies to other dolphins and even to the large whales. Common Dolphin The common dolphin averages 8 ft (2.4 m) in length and 165 lb (75 kg) in weight.

It has a dark blue or black upper body, a white underbody, golden stripes on the sides, and a sickle-shaped dorsal fin. Its pronounced, slim beak, holding 100 teeth, is separated from its snout by a deep groove. A fast swimmer, it travels in large schools in warm waters and is noted for leaping alongside boats for long distances. Its life span is about 50 years. Bottle-nosed Dolphin The bottle-nosed dolphin is blue-gray with a dorsal fin and white belly. Its average length is 9 ft (2.7 m) and its average weight 350 lb (160 kg). Its domed forehead, called the melon, contains an oily substance thought to protect the brain case and to act as an acoustic lens. With age the 200 or more teeth of the bottlenose wear down, hence the name truncatus. Members of this species live about 25 years. Bottle-nosed dolphins swim in large schools with a social organization and hierarchy, hunting the small fish, crustaceans, squid, and cuttlefish that make up their diet.

They have been clocked swimming at 30 mi (48 km) per hour, although 20 to 24 mi (32–39 km) per hour is their usual speed. They can dive 70 ft (20 m) and remain underwater for 15 minutes. They sleep by night, just below the surface of the water, rising for air every three or four minutes. Their aquatic natural enemies are sharks and killer whales; these they attempt to outswim, using complex evasive strategy, or batter to death, acting in a group. If one of their number is injured or sick they make every effort to rescue it, holding it above the water for air. Play behavior is highly developed in the bottlenose from infancy through old age, and in this connection it displays considerable tool-making, tool-using, and manipulative ability; for example, a dolphin has been observed to kill a fish, strip its skeleton, and use the bones, held in the mouth, to pry another fish out of a crevice. Sex play is frequent and is initiated by any individual toward any other, without regard to size, age, sex, relationship, or even species; approaches to human beings and to turtles are common.

Courtship and impregnation occur mainly in spring, when males vie for the attention of the females. A single calf, 3 1-2 ft (97 cm) long and weighing 30 lb (14 kg), is born tail first after a gestation of 12 months. The mother or a female assistant bites the umbilical cord in two and pushes the calf to the surface to breathe; it is nursed for one to two years. One female may watch over several calves while the mothers hunt, or during battle. The senses of the bottlenose have been subjected to intensive investigation, as have their intelligence and their remarkable systems of echolocation and communication. In relation to body size, the brain of the adult bottlenose is comparable in size to that of humans; it is twice as convoluted and possesses 1 1-2 times as many cells. The bottlenose has partially stereoscopic vision that is keen both in water and in air; when the animal leaps from one medium to the other, its brain corrects for the difference in refractive index. The eye has a glowing layer for night vision and a brownish filter that is lowered over the iris in bright sunlight.

The brain has no olfactory lobe and the sense of smell is presumably missing, but the taste buds are well developed and are used to detect underwater chemical traces, as when the dolphin tracks fish. Echolocation and Communication Dolphins produce an enormous variety of sounds, up to frequencies ten times those heard by human beings. The sounds are apparently produced by a complex of anatomical structures including the blowhole with its air sacs and valves. Each dolphin has a signature whistle with which it identifies itself; a calf soon learns to recognize its mother's whistle. Clicking and rapid creaking sounds are the basis of the echolocation mechanism (sonar) with which the dolphin gathers extremely precise information about the size, location, and nature of surrounding objects. Dolphins communicate by means of a demonstrably descriptive language understood by more than one species, using all the sounds in their repertory. They are observed to converse, and it has been repeatedly shown that one animal can convey instructions to another. Computer-aided efforts are being made, so far without success, to learn the dolphin language and to teach dolphins human speech, either in its normal form or translated into whistle combinations.

Interaction with Humans Dolphins are capable of imitation and memorization; they demonstrate foresight, learn from observation, communicate experience, solve complex problems, perform elaborate tasks, and learn multiple procedures simultaneously. Their so-called training is in fact a discipline structured around play, using their natural behavior as the basis for involved maneuvers; they appear to perform primarily for their own enjoyment. In situations of great stress in captivity they have been known to commit suicide by starvation, battering against walls, or drowning. There are many reports of dolphins rescuing people from drowning. The United States and Russian/Soviet navies have spent vast sums to reach a greater understanding of dolphin echolocation, which could have countless military applications. The U.S. navy has trained dolphins to act as messengers to underwater stations, to rescue wounded scuba divers and protect them from sharks, to locate and mark underwater mines, and to seek and destroy submarines, using kamikaze methods; this last project met with considerable public criticism. Classification Dolphins are classified in the phylum Chordata Chordata , phylum of animals having a notochord, or dorsal stiffening rod, as the chief internal skeletal support at some stage of their development.

Most chordates are vertebrates (animals with backbones), but the phylum also includes some small marine invertebrate animals. ..... Click the link for more information. , subphylum Vertebrata, class Mammalia, order Cetacea, family Delphinidae. Bibliography See W. N. Kellogg, Porpoises and Sonar (1961); K. S. Norris, ed., Whales, Dolphins and Porpoises (1966); E. Devine and M. Clark, The Dolphin Smile (1967); R. Stenuit, The Dolphin, Cousin to Man (1968); D. K. and M. C. Caldwell, The World of the Bottlenosed Dolphin (1972); M. M. Bryden and R. Harrison, ed., Research on Dolphins (1986); R. Ellis, Dolphins and Porpoises (1989); H. Whitehead and L. Rendell, The Cultural Lives of Whales and Dolphins (2014). Dolphin The dolphin is a traditional alternate name for the sign Pisces.

Dolphin freestanding supports that take up the loads when vessels dock and fall foul. There are mooring dolphins, breasting dolphins, swinging dolphins, and guiding types. They may be rigid, with a slight lateral yield, or flexible. The dolphins are installed directly in front of berths that are not designed to withstand horizontal loads and in front of sloping structures to prevent vessels from falling foul of the shore. They are also placed in roadsteads for the benefit of vessels unloading or waiting to unload. Dolphins placed at approaches to berths or at the entrance to a lock or harbor help vessels to hold the correct position, and dolphins of the floating type serve to hold vessels off from mooring structures. REFERENCES See: Guide dolphin 1. any of various marine cetacean mammals of the family Delphinidae, esp Delphinus delphis, that are typically smaller than whales and larger than porpoises and have a beaklike snout 2. river dolphin any freshwater cetacean of the family Platanistidae, inhabiting rivers of North and South America and S Asia. They are smaller than marine dolphins and have a longer narrower snout 3.

either of two large marine percoid fishes, Coryphaena hippurus or C. equisetis, that resemble the cetacean dolphins and have an iridescent coloration 4. Nautical a post or buoy for mooring a vessel Dolphin (dreams) Dolphins represent friendliness, communal living, rescue, communication, and affection. They are water dwelling mammals and in our dreams they represent our willingness and ability to navigate through emotions. They represent positive messages from our unconscious minds. Dolphins could also represent a positive connection between our consciousness and to those parts of the psyche that are a mystery and largely unconscious. Harbour Porpoise | WiseOceans Harbour Porpoise Kindly compiled by Gemma Cave & Olivia Harries of The Hebridean Whale and Dolphin Trust Harbour posrpoise at surface showing characteristic triangular dorsal fin General Description The harbour porpoise is a small, inconspicuous species of cetacean found in coastal waters of the northern hemisphere. It is the smallest species found in the Scottish Hebrides. Harbour porpoises are small and rotund, with no beak, a small, triangular dorsal fin, and are dark grey with paler coloured bellies.

Distribution Harbour porpoise are found in coastal waters in the northern hemisphere, between about 10° to 70° N. They are a relatively common, and resident, species of the west coast of Scotland. Interesting Facts They are sometimes known as ‘puffing pigs’ because of the noise they make when they surface. The Scottish Gaelic name for harbour porpoise is peileag. They are not considered to be a sociable species and are not thought to vocalise, but they do echolocate. Food: Small schooling fish such as herring, sprat, sand eels, as well as some cephalopods. Lifespan: Up to 24 years Size: 1.4 – 1.7m long, 50 – 80 kg, females are slightly larger than males. Reproduction: Harbour porpoise are quite short-lived so, once females reach sexual maturity at about three years, they can then produce a calf each year for several years. Gestation lasts for up to 11 months, meaning females can be pregnant and lactate at the same time.

Feeding & Hunting: Usually forage alone or in small groups, although larger cooperative feeding aggregations are sometimes seen. Threats Predators include large sharks and killer whales. In the Hebrides, there have been several accounts of killer whale hunting harbour porpoise. They are also susceptible to being disturbed or killed by many human activities. Because of their feeding habits, they are at a high risk of entanglement in fishing gear. It is believed that several thousand may be entangled and drowned each year in UK waters, primarily in gill nets. Harbour porpoise distribution overlaps with areas of the coast that are most heavily used by people, which means they are exposed to high levels of shipping traffic, coastal development and other human sources of disturbance. Hearing is the most important sense for porpoise, but the loud underwater noises caused by vessels, military activity and seal scarers (Acoustic Deterrent Devices) used by some fish farms may impact on their distribution and welfare. HWDT’s boat-based research programme aims to develop an understanding of the most important habitats and the key habitat requirements for harbour porpoise off the west coast of Scotland to help protect the species in the future.

Conservation Status & International Protection The harbour porpoise is protected under UK and EU law, principally under Schedule 5 of the Wildlife and Countryside Act 1981, the Nature Conservation (Scotland) Act 2004 and by the 1992 EU Habitats and Species Directive. The populations in the Black and Baltic seas are thought to be the most threatened. Like other cetacean species, harbour porpoise are important indicators of overall ecosystem health. How can people help? By adopting environmentally responsible attitudes, we can all contribute to more sustainable uses of the marine environment. Simple lifestyle changes, such as recycling, using environmentally-friendly products and choosing responsibly sourced seafood, will help to improve the overall health of our oceans. If you encounter harbour porpoises at sea, be considerate in the way you approach them. They are elusive animals that usually steer clear of vessels, so enjoy them from a safe distance, and keep a constant speed and heading so as not to disturb them. If you see harbour porpoise off the west coast of Scotland, you can report your sighting to the Hebridean Whale and Dolphin Trust via the online sightings form at to contribute to a better understanding of this remarkable little cetacean.

Best places in the world to see these creatures: Within their geographic range, look for harbour porpoise close to the coast and in bays, estuaries and harbours. Patience is required as they are elusive animals that can be hard to spot, as they surface only briefly to breathe and can be particularly tricky to see in rougher seas. In the UK, look for tour operators with the ‘WiSe scheme’ accreditation to ensure responsible wildlife-watching. For ethical reviews and rating system for whale watching trips to see Harbour Porpoise visit Scientist Profile: Olivia Harries, Biodiversity Officer The Hebridean Whale & Dolphin Trust ( HWDT ) Year(s) Founded: 1994 Description/Background of work The Hebridean Whale and Dolphin Trust (HWDT) is dedicated to enhancing knowledge and understanding of Scotland’s whales, dolphins and porpoises and the Hebridean marine environment through education, research and working within Hebridean communities as a basis for the lasting conservation of local species and habitats.

Specifically, HWDT conducts long-term monitoring of cetacean abundance, distribution and habitat use, engages a wide range of people in marine environmental education through hands-on, outdoor learning experiences and provides local communities with volunteering and training opportunities to promote sustainable management of marine resources. Importance of work As the only long standing research organisation on the west coast of Scotland, HWDT’s projects are vital to the effective management of marine megafauna populations. Our research is at the centre of marine spatial planning, and the construction of aquaculture sites and renewable energy sources can depend on the results from our analyses. Because of the high degree of behavioural and social flexibility that some species of cetaceans (mostly dolphins) have demonstrated throughout their range, it is essential to understand factors affecting local cetaceans, if their populations are to be managed and conserved. Information on habitat use also seems applicable to coastal management plans. Websites: / Funding bodies The Hebridean Whale and Dolphin Trust is a small, locally-based charity reliant on income from supporters, donations and funding.

HWDT is grateful to currently receive funding and support from: Awards for All Scotland, Earthwatch, Miller Philanthropy, Scottish Natural Heritage, The Bromley Trust, The Robertson Trust, WWF and a number of smaller bodies. Surveys around St Kilda, Scotland Volunteer /Paid Work Opportunities HWDT advertise all paid and voluntary positions on the website . From May to September each year, paying volunteers assist with data collection onboard the research vessel Silurian. Details of these live-aboard trips can also be found on the HWDT website. There are many other opportunities for land-based volunteers so please contact HWDT to find out more. Dolphin vs Porpoise - Difference and Comparison | Diffen Dolphin vs. Porpoise Diffen › Science › Biology › Zoology › Animals › Marine Life Dolphins and porpoises are cetaceans — marine mammals — that are closely related to whales. Dolphins belong to the Delphinidae family and are up to 30 feet long. Porpoises, belonging to the Phocoenidae family, are smaller and stouter, with other anatomical differences . Though both animals are very intelligent , dolphins are deemed to be more social and live in larger, more stable groups.

Although "dolphin" and "porpoise" are often used interchangeably, the term porpoise should refer only to the Phocoenidae family, in which there are seven porpoise species. Comparison chart Dolphin versus Porpoise comparison chart Dolphin Dolphin sizes vary from 4 ft to 30 ft. Porpoises are usually smaller (4.9ft-8.2 ft) but stouter than dolphins. Phylum Porpoises have flattened, spade-shaped teeth. Order Dolphins are marine mammals closely related to whales and porpoises. Porpoises are smaller marine mammals related to whales and dolphins. Social Behavior Dolphins are very social and tend to show a less fear of human than porpoises . Porpoises are relatively shy, and are therefore rarely seen in marine animal shows. Family Several families, including Delphinidae (oceanic dolphins), Iniidae (mostly extinct river dolphins), Platanistidae (Indian river dolphin), Pontoporiidae (La Plata dolphin) Phocoenidae Dolphins are found in all oceans Porpoises are only found in the Pacific Scientific classification (Order & Family) Dolphins are cetaceans of the family Delphinidae.

Porpoises are small cetaceans of the family Phocoenidae. Gestation period Most dolphins have a curved dorsal fin. A porpoise's dorsal fin is generally triangular, somewhat like sharks. Head Dolphins have a round, bulbous "melon" in the head and elongated jaws that often form a distinct beak. Porpoises have small, rounded heads and blunt jaws instead of beaks. Contents: Dolphin vs Porpoise Dolphin vs. Porpoise Anatomy Close up of a dolphin's head The primary differences between dolphins and porpoises are anatomical. Externally, one can tell the difference between the two animals by looking at the head and dorsal fins. Dolphins usually have a “beak” that makes them appear "long-nosed," while porpoises do not have a beak and thus appear more "flat-faced." The dorsal fins on dolphins are usually curved or hooked, while those on porpoises are more triangular in shape. Up close, one can distinguish the two by their teeth: dolphins have cone-shaped teeth, but porpoises have flat or spade-shaped teeth. Dolphins and porpoises vary in size, with dolphins generally being the larger of the two animals.

The orca, or killer "whale," which is actually a dolphin, genetically , can be up to 35 feet long, for example, and the Hector's dolphin of New Zealand is sometimes smaller than 4 feet. On average, porpoises, which are more darkly-colored than dolphins, are between 5 and 8 feet long. Both species breathe air from blowholes at the top of their head. And, like almost all mammals, they give live birth to their young and nurse their offspring. Dolphins and porpoises even have hair, but nearly all of it is lost shortly after birth. Of the three types of fins found on dolphins and porpoises, only the pectoral fins (flippers), which are used for stopping and steering underwater, contain bones. These fins actually contain the same number of bones as a human arm and end in five digits that are structured similarly to fingers. Scientists theorize that these bones come from dolphins' and porpoises' land-dwelling ancestors some 50 million years ago. The flippers on dolphins and porpoises contain finger-like digits. Click to enlarge.

Beyond the pectoral fins, the dorsal, or back, fin provides stability as the dolphin and porpoise move quickly through water (up to 25 mph). This dorsal fin, along with the tail flukes, is made of collagen, a fibrous connective tissue similar to cartilage. Echolocation Use and Other Senses Both dolphins and porpoises use echolocation for navigating underwater, finding food, avoiding predators, and communicating with other members of their species. Porpoises' heads lack the "melon" structure that helps dolphins with echoes and signals, but they make up for that by having somewhat better eyesight. The small external ear opening is about two inches behind the eye in both animals. Neither dolphins nor porpoises rely much on their sense of smell. Vocalizations are more extensive and frequent with dolphins, and can travel longer distances than those recorded for porpoises. Reproduction Males of both species have two genital openings on their ventral side, while females have four: two for their sex organs and two for lactation, with teats found inside the body. Mating seasons for both species tend to be short, with dominant males having multiple mates. Pair bonding is more frequently observed in dolphins, often for life.

Gestation periods are very similar, between 7 and 12 months, with 1-2 calves born, though most often only one. Calves are weaned after about a year. Social Behavior of Dolphins and Porpoises Dolphins tend to live in pods, or groups, of up to a dozen individuals. Where food is abundant, "superpods" exceeding 1,000 dolphins have been observed. Dolphins coordinate hunts and communicate for other reasons by combining whistles, clicks, and ultrasonic sounds. Porpoises are relatively shy and are seen alone or in groups containing a few individuals. They are rarely in large pods. Their grouping behavior does not result in stable associations, but ephemeral relationships that change as individuals join or leave. Porpoises can act in a coordinated fashion even when they are hundreds of feet apart, using echolocation for finding prey and staying together in a pod, but do not use it to communicate as often as dolphins do. Dolphin vs. Porpoise Intelligence Dolphins and porpoises are highly intelligent. They have large, complex brains and are self-aware like humans. They are among the few species in the world that can identify themselves in a mirror.

Years of research have allowed scientists to make an extensive case for protecting cetaceans (including porpoises, dolphins, and whales ) from fishing and unrestricted hunts. [1] This and potential extinction are reasons for international bans on whale hunting and the prohibition of net-based tuna fishing that can trap and drown dolphins. Bottlenose dolphins have been observed and recorded calling out the specific names of loved ones when they become separated. Other than humans, dolphins are the only known species to explicitly call each other by name . Dolphins have also been observed staying with injured or ill individuals, and have been known to help humans adrift at sea. Because they are more gregarious, dolphins have become popular animals for training in captivity, a situation porpoises do not adapt to well. References Sea Watch Foundation » Species Identification Species Identification Download our bite size guides to UK whale and dolphin species. Species ID British Isles – most common species in the UK particularly in the South and South-West, including the Irish Sea. Harbour porpoise (Phocoena phocoena) General Guide When a live cetacean is seen, you may only have a very brief time to note any distinctive features.

For this reason it is very important to know exactly what to look for. First, obtain some idea of the animal’s length. Where possible, compare it to some object of known length in the vicinity, such as a boat. Otherwise, be prepared for the estimate to be only very approximate, but try to place the animal within a size range, for example 4-8, 6-10, 8-12, 10-20, 15-30, 25-50, 40-60, greater than 60 feet. This should take a matter of seconds (though be prepared to have to estimate on the basis of only a dorsal fin and part of the back). On the first look, see if there is a dorsal fin at all (right whales do not have one, and the sperm whale has only a series of ridges along the back). If one exists, note its position (either halfway or two-thirds along the back), its relative size and its shape.

The harbour porpoise can readily be distinguished from the various dolphin species not only by its smaller size (~ 4ft total length compared with 6-12ft in the case of dolphins), but also by its small triangular dorsal fin. Most dolphins have recurved fins, somewhat sickle-shaped. Of the whales, most species have a small fin two-thirds of the way along the back. The two exceptions with centrally placed dorsal fins which are likely to be seen in Northern European waters, are the long-finned pilot whale, with a taller curved fin that in adults is more rounded and flag-shaped, and the killer whale, with a conspicuous fin that in the adult male, reaches a height of six feet. The shape of the dorsal in both species varies with age and between the sexes, being more curved in females and immatures. In the male killer whale, the fin is actually triangular, sometimes even swept forward. Most other whales have small curved fins. In the blue, sei and minke whales, the relative size of the fin increases as the total length of the whale diminishes. It also tends to be more curved, a trait most pronounced in the sei. Observers may confuse the minke whale with the northern bottlenose whale.

The head shape is very different, but often the identification is based primarily on the view of a back and a fin. Both are of similar size, and in both, the fin is two-thirds along the back. The best way to distinguish them is to look for a more upright and deeply curved fin in the bottlenose whale, and if one is close, a conspicuous white patch on the outer surface of the minke whale’s flippers. Other beaked whales such as Cuvier’s beaked and Sowerby’s beaked whale are very difficult to identify at sea. In very calm conditions, they may lie at the surface allowing one to see the rounded head, prominent beak, and in males, a single pair of teeth in the jaw. They have a small but distinct curved dorsal fin two-thirds along the back. The larger species are best separated either by their characteristic head shapes, or the size and shape of their blows (only the sperm whale has a pronounced forward blow, and the right whale has a double blow) and by their surfacing and diving characteristics. Many of the whales are rather uniform in colouration: dark on the back and flank, pale on the belly (often concealed).

For the smaller dolphins, however the markings on their flanks, used in combination with the length of the beak, can confirm identification according to the species. The only long-beaked species in our waters are the common and striped dolphins, and the latter only occasionally come into the region, from the south. The common dolphin has a characteristic hourglass pattern of tan on the flanks, extending to the back only on the tail stock; the striped dolphin has a dark blaze on its flanks, sweeping forward from the dorsal fin, and three distinct dark lines of variable length extending back from the eye. The white-beaked dolphin, the commonest dolphin in northern Britain, is often misidentified as white-sided because it has white patches on the sides. But, unlike the species of that name, the white area almost invariably extends over the back behind the dorsal fin, and in some individuals, the white is not very distinct. The Atlantic white-sided dolphin, on the other hand, has a very conspicuous long, white, oval patch on the flanks behind the dorsal fin, from which rises a yellow ochre blaze. From a distance, the large curved dorsal fin of the white-beaked dolphin is sometimes confused with that of a female and immature killer whale.

The same goes for that of the Risso’s dolphin (locally termed Grampus), though it is usually readily distinguished by its frequent pencil-like markings on the uniform grey flanks, which whiten with age. (It is possible that some sightings of white whales are of old Risso’s dolphins.) The bottlenose dolphin, though probably the most familiar dolphin to many, is ironically one of the more difficult to identify with certainty, having no distinctive pattern markings. Instead, it is uniformly dark brown or grey above and pale below, the one shade merging inconspicuously into the other down the flanks. External features are generally more useful for species identification than behaviour patterns because the latter can vary with circumstance. Nevertheless, sometimes these can provide useful support. Porpoises, for example, rarely do more than break the surface, so that leaping animals are much more likely to be dolphins. Humpback and sperm whales frequently throw their tail into the air before making a deep dive. Humpbacks are perhaps the most acrobatic of large whales, not uncommonly propelling themselves right out of the water. They also have large tail flukes and very lone white flippers.

Some whales, such as the minke whale and fin whale, will sometimes lunge thr0ugh the surface so that their entire heads can be seen and occasionally also breach. Search Sea Watch Foundation is grateful for funding in the form of donations, grants or contracts from the following bodies… Please review…

Question: Used primarily for stability, where on a fish, whale, dolphin, or porpoise, do you find the dorsal fin?
Answer: Back