What is the difference between sharks and dolphins?

i am doing a project where i need to make a chart describing the differences between sharks and dolphins

sharks take out limbs, dolphis just smile at you.

Sharks bite you / kill you.Dolphins just swim around.

Sharks are mean and dolphins aren't.

dolphins are mammals and sharks are not.

sharks are fish, dolphins are mammals

dolphins are mammels and sharks are fish

dolphins communicate with each other, and they have that blowhole thing on their back. dolphins are easier to train than sharks, and they are much more agile in the water. oh, dolphins masterbate!

Watch the movie Shark Tale.

Sharks are a group (superorder Selachimorpha) of fish, with a full that cartilaginous skeleton, a streamlined body plan, with normally 5, but up to 7 (depending on species) gill slits along the side of, or beginning slightly behind, the head (in some species, a modified slit called a spiracle, is located just behind the eye), dermal denticles covering the body to protect from damage, parasites and improve fluid dynamics, and rows of replaceable teeth in the mouth.CharacteristicsSharks have keen olfactory senses, with some species able to detect as little as one part per million of blood in seawater. They are even more attracted to the chemicals found in the gut of many species, and often linger near or in sewage outfalls. Some species, such as Nurse sharks, have external barbels that greatly increase their ability to sense prey. The short duct between the anterior and posterior nasal openings are not fused like in bony fish.Shark eyes are similar to the eyes of other vertebrates, including similar lenses, corneas and retinas, though their eyesight is well adapted to their marine environment with the help of a tissue called tapetum lucidum. This tissue is behind the retina and reflects light back to the retina, thereby increasing visibility in the dark waters. The effectiveness of the tissue varies, with some sharks having stronger nocturnal adaptations. Sharks have eyelids, but they do not blink because the surrounding water cleans their eyes. To protect their eyes some have nictitating membranes. This membrane covers the eyes during predation, and when it is being attacked. However, some species, including the Great White, do not have this membrane, but instead roll their eyes backwards to protect them. Sharks generally rely on their superior sense of smell to find prey, but once they are close they also use the lateral lines running along their sides to sense movement in the water and also employ special sensory pores on their heads (Ampullae of Lorenzini) to detect electrical fields created by prey and the ambient electric fields of the ocean. Their teeth are not attached to the jaw, but embedded in their flesh, and in many species are constantly replaced throughout the shark's life. The lower teeth are primarily used for holding prey, while the top are used for cutting into it. (Gilbertson, 7.3) Closeup of a Whitetip reef shark.Sharks also have a sharp sense of hearing and can hear prey many miles away. A small opening on each side of their head (not to be confused with the spiracle) leads directly into the inner ear through a thin channel. The lateral line shows a similar arrangement as it is open to the environment via a series of openings called lateral line pores. This is a reminder of the common origin of these two vibration and sound detecting organs that is grouped together as the acoustico-lateralis system. In bony fish and tetrapods the external opening into the inner ear has been lost.A Blacktip Reef Shark in French PolynesiaThere are exceptions to the "large", "marine" (as in 'ocean-going') and "predatory" portions of the characterization. Sharks include everything from the hand-sized Pygmy Shark, a deep sea species, to the Whale Shark, the largest fish (although sharks are not closely related to bony fish) which is known to grow to a maximum length of approximately 15 metres (49 feet) and which, like the great whales, feeds only on plankton. Although not unique among sharks, the Bull Shark is the better known of several species to regularly swim in both salt and fresh water environments (most famously in Lake Nicaragua, in Central America) and in most deltas. A few of the larger species, the Mako and White Shark, are mildly homeothermic, able to maintain their body temperature at a level above the ocean's temperature. This is possible because of the presence of the rete mirabile, a counter current exchange mechanism that reduces the loss of body heat.Like other fish, sharks extract their oxygen from seawater as it passes over their gills. Due to their size and the nature of their metabolism, sharks have a higher demand for oxygen than most fish and they cannot rely on ambient water current to provide an adequate supply of oxygenated water. If a shark were to stop swimming, the necessary water circulation for respiration would become too low and the animal could suffocate, although some sharks have been known to "nap" on the bottom. Some sharks, like the Blacktip Reef Shark and Nurse Shark, can pump water over their gills as they rest. There are also known instances, such as in certain caves along the Yucatan coast, where sharks of varying species rest on the cave floors and allow the fresh water outflow to pass over them. The outflow is strong enough to allow for respiration, and it is believed that the reason for this behaviour is that the fresh water helps remove certain parasites. Also, unlike other fish, sharks do not have gas-filled swim bladders, but rather rely on an oil-filled liver for (limited) buoyancy, so they sink when they stop swimming; a resting shark always sinks to the sea bed. Sand tiger sharks are known to gulp air at the surface and store it in their stomach to provide buoyancy.Unlike bony fish, the sharks have a complex dermal corset arranged as a helical network and made of flexible collagenous fibres surrounding their body. This works as an outer skeleton, providing attachment for their swimming muscles. The sharks saves more energy while swimming this way than if they didn't have their collagenous corset. A similar arrangement of collagen fibres has been discovered in dolphins and squids.Their dermal teeth gives them hydrodynamic advantages as they are reducing the turbulence when swimming.A shark, if inverted, enters a natural state of paralysis. Researchers use this condition for handling sharks safely.A popular myth is that sharks are immune to disease and cancer, however, this is untrue and there are both diseases and parasites that affect sharks. The evidence that sharks are at least resistant to cancer and disease is mostly anecdotal and there have been few, if any, scientific or statistical studies that have shown sharks to have heightened immunity to disease. [1]Urine in sharks accumulates in the blood and is then secreted through the skin.Their upper jaws are not attached to the skull.Shark attacksThe fear of sharks has been fueled by a few rare instances of unprovoked attack, such as the Jersey Shore Shark Attacks of 1916, and by sensationalized fiction and film, such as the Jaws series. The creater of the Jaws phenomenon, Peter Benchley, has himself in recent years attempted to dispel the myth of sharks being man-eating monsters. In 2005 there were worldwide a total of 58 unprovoked attacks of which 4 were fatal [2]. Several hundred people die annually from lightning strikes and 1.3 million people die from diseases transmitted via mosquito bites.Snorkeler with Blacktip Reef Shark.Contrary to popular belief, only a few sharks are dangerous to humans. Out of more than 360 species, only 4 have been confirmed to have killed appreciable numbers of humans in unprovoked attacks: the Great White, Tiger, Bull, and Oceanic Whitetip sharks. These sharks, being large, powerful predators perfectly capable of eating humans, may sometimes attack and kill people, but all of the above sharks, even the Great White, have been filmed in open water, with no cage [3], time and time again, without incident.There are many theories about why sharks sometimes attack people. Some claim that the shark is confusing a human for a seal or other prey animal; this would be typical in the case of an attack against a surfer. This is because the shape of a surfer lying on a board closely resembles a seal from beneath the surface. Also, sharks have sensory organs on their nose to pick up electrical signals, such as movement. Often the shark that attacks a human will make only one bite and then go away. This behaviour has many possible explanations, one being that humans don't taste good (or at least, as good), or are lacking the necessary fat, and another being that sharks normally make one swift attack, and then retreat and wait for the victim to die, or exhaust itself, before it comes back to feed. This protects the shark from retribution from a wounded and aggressive target, but also allows humans the time to get out of the water and survive. Another theory is that the electrical receptors, which pick up movement, do not pick up the same signals from a wounded human as they would a wounded seal, and so they are more cautious. In fact, it has recently been shown that surfers do not give off the same electrical signals as seals, or it is thought there would be far more attacks.Contrary to popular belief the Great White Shark does not target humans as prey.A number of other species (perhaps 10 - 15) have threatened, attacked, and/or bitten, but not killed large numbers of humans without being obviously provoked. This group contains the Mako, Hammerhead, Gray Reef, Black Tip Reef, Lemon, Silky and Blue sharks. These sharks are also large, powerful predators which can be provoked simply by being in the water at the wrong time and place, but they are normally considered less dangerous to divers and swimmers than the previous group. In most cases, if a person moves away calmly, or remains still, they will be ignored. Many shark species are known to "display" when feeling threatened, and it is ill-advised to remain in the vicinity at such a time as this would generally be considered enough provocation to warrant an attack.A few other shark species do attack people every year, producing wounds that can potentially kill, but this occurs either specifically because they have been provoked, or through mistaken identity due to water conditions or the like.SpeedIn general, sharks swim ("cruise") at an average speed of 8 kilometers (5 miles) per hour, but when feeding or attacking, the average shark reaches speeds upwards of 19 kilometers (12 miles) per hour. One exception to this generality is the Mako shark, whose speed may range upwards of 48 kilometers (30 miles) per hour. The Mako shark is considered to be the fastest shark and one of the fastest fish. Also the Great White Shark is capable of surprising bursts of speed. These exceptions may be due to the "warm-blooded", or homeothermic, nature of their physiology.EtymologyUntil the late 16th century sharks were usually referred to in the English language as sea-dogs. The name "Shark" first came into use around the late 1560s to refer to the large sharks of the Caribbean Sea, and later to all sharks in general. The name may have been derived from the Mayan word for shark, xoc, pronounced "shock" or "shawk". The collective noun for a group of sharks is a shiver.ClassificationBasking Shark, Cetorhinus maximusSharks belong to the superorder Selachimorpha in the subclass Elasmobranchii in the class Chondrichthyes. The Elasmobranchii also include rays and skates; the Chondrichthyes also include Chimaeras. It is currently thought that the sharks form a polyphyletic group: in particular, some sharks are more closely related to rays than they are to some other sharks.There are more than 360 described species of sharks.The first sharks appeared in the oceans 400 to 350 million years ago. Most of the species we know today are as old as the Jurassic period. There are eight orders of sharks, listed below in roughly their evolutionary relationship from more primitive to more modern species:Hexanchiformes: Examples from this group include the cow sharks, frilled shark and even a shark that looks on first inspection to be a marine snake. Squaliformes: Examples from this group include the bramble sharks, dogfish sharks and roughsharks, and prickly shark. Pristiophoriformes: These are the sawsharks, with an elongated, toothed snout that they use for slashing the fishes that they subsequently eat. Squatiniformes: Angel sharks. Heterodontiformes: They are commonly referred to as the bullhead or horn sharks. Orectolobiformes: They are commonly referred to as the carpet sharks, including zebra sharks, nurse sharks, wobbegongs and the largest of all fishes, the whale shark. Carcharhiniformes: They are commonly referred to as the groundsharks, and some of the species include the blue, tiger, bull, reef and oceanic whitetip sharks (collectively called the requiem sharks) along with the houndsharks, catsharks and hammerhead sharks. They are distinguished by an elongated snout and a nictitating membrane which protects the eyes during an attack. Lamniformes: They are commonly referred to as the mackerel sharks. They include the goblin shark, basking shark, megamouth shark, the thresher sharks, mako shark and great white shark. They are distinguished by their large jaws and ovoviviparous reproduction. The Lamniformes include the extinct Megalodon (Carcharodon megalodon), which like all extinct sharks is only known from its teeth (the only bone found in these cartilaginous fishes, and therefore the only fossils produced). A reproduction of the jaw was based on some of the largest teeth (up to almost 17 cm (7 inches) in length) and suggested a fish that could grow 25 metres (80 feet) long to 30.5 metres (100 feet). The jaw was realized to be inaccurate, and estimates revised downwards to around 13 metres (43 feet) to 15.9 meters (52 feet).ReproductionClaspers of male Spotted Wobbegong shark, Orectolobus maculatusThe sex of a shark can be easily determined. The males all have their pelvic fins modified into a pair of claspers. The name is somewhat misleading as they are not used to hold on to the female, but are the shark's version of the mammalian penis. (As a side note, Class Chondrichthyes has the distinction of having the animal with the largest intromittent organ — an organ used for transmitting sperm — in relation to body length. This animal is the clearnose skate (Raja eglanteria) which has claspers of 15 cm (6 in) in size on a fish that reaches 1 m (3 feet) in length.)Mating has rarely been observed in sharks. The smaller catsharks often mate with the male curling around the female. In the less flexible species the two sharks swim parallel to each other while the male inserts the clasper into the female's oviduct. Many females in the larger species have bite marks that appear to be a result of a male grasping her to maintain position. The bite marks can also come from the courtship of the sharks. The male may come and bite the edges of the female to show his interest. In some species, females have evolved thicker skin to withstand the bites a male will give them during mating.Sharks have a much different reproductive strategy than most fishes. Instead of producing huge numbers of eggs and larvae (99.9% of which never reach sexual maturity in fishes that use this strategy) sharks normally produce around a dozen pups, some species up to 70-80 and some as few as 2-3. These pups are either protected by egg cases or born live. No known sharks provide parental protection for their young, but females have a hormone that is released into their blood during the pupping season that apparently keeps them from feeding.Egg case of Port Jackson shark - found on Vincentia beach, Jervis Bay Territory, AustraliaThere are three ways in which shark pups are born:Oviparity - Some sharks lay eggs. In most of these species, the developing embryo is protected by an egg case with the consistency of leather. Some of these cases are corkscrewed into crevices for protection. When they wash up empty on beaches, the egg cases are sometimes called mermaid's purses. Oviparous sharks include the horn shark, catsharks, Port Jackson Sharks, and the swell shark. Viviparity - These sharks actually maintain a placental link to the developing young, more analogous to mammals than other fishes. The young are born alive and fully functional. Hammerheads, the requiem sharks (like the bull and tiger sharks), the basking shark and the smooth dogfishes fall into this category. Dogfishes also have the longest known gestation period of any shark, 22 months. The blue shark produces the most young of sharks that have had the number of pups recorded, the maximum reported being 82. Ovoviviparity - Most sharks utilize this method. The young are nourished by the yolk of their egg and by fluids secreted by glands in the walls of the oviduct. The eggs hatch within the oviduct, and the young continue to be nourished by the remnants of the yolk and the oviduct's fluids. As in viviparity, the young are born alive and fully functional. Sometimes they are functional even before being born, as some species practice oophagy, where the first to hatch eat the remaining eggs in the oviduct. Sand tigers, makos, threshers, porbeagles and possibly great whites have oophagous young. The survival strategy for the species that do this is that the young are able to grow to an even larger size before being born. The whale shark is now considered to be in this category after having been classified as oviparous for a long time. Whale shark eggs found are now thought to have been aborted. Most ovoviviparous sharks generally give birth in sheltered areas, including bays, river mouths, and shallow reefs. They choose such areas mainly because of the protection from predators (mainly other sharks) and the abundance of food. Shark sensesSharks have two senses that many animals do not have:Electroreception: The Ampullae of Lorenzini are the electroreceptor organs of the shark, and they vary in number from a couple of hundred to thousands in an individual. The shark has the greatest electricity sensitivity known in all animals. This sense is used to find prey hidden in sand in bottom feeding sharks, by detecting the electric fields inadvertently produced by all fish. It is this sense that sometimes confuses a shark into attacking a boat: when the metal interacts with salt water, the electrochemical potentials generated by the rusting metal are similar to the weak fields of a prey, or in some cases, much stronger than the prey electric fields, enough to attract sharks from miles away. The oceanic currents moving in the magnetic field of the earth also generate electric fields that can be used by the sharks for orientation and navigation. Lateral line - This system is found in most fish, including sharks. It is used to detect motion or 'sound' in the water. The shark uses this to detect other organisms moving, especially wounded fish. The shark can 'hear' frequencies in the range of 25 to 50 Hz using this sense. A Nurse Shark, a kind of bottom-feeding shark[edit]Shark fisheryEvery year, 100 million sharks are killed by people in commercial and recreational fishing. In the past they were killed simply for the sport of landing a good fighting fish (mako sharks for instance). Sharkskin is covered with dermal denticles, which are similar to tiny teeth. It was used for purposes similar to sandpaper. Other sharks are hunted for food (Atlantic thresher, mako and others), and some species for other products.Sharks are a common seafood in many places around the world, including Japan and Australia. In the Australian State of Victoria shark is the most commonly used fish in fish and chips, in which fillets are battered and deep fried or crumbed and grilled and served alongside chips. When served in fish and chip shops, it is called flake.Sharks are often killed for shark fin soup, in which many sharks are hunted for their fins, which are cut off with a hot metal blade before the live animal is tossed back into the water. There have been cases where hundreds of de-finned animals were swept up on local beaches without any way to convey themselves back into the sea. Conservationists have campaigned for changes in the law to make finning illegal in the U.S.Sharks generally reach sexual maturity slowly and produce very few offspring in comparison to other fishes that are harvested. This has caused concern among biologists regarding the increase in effort applied to catching sharks over time, and many species are considered to be threatened.Some organizations, such as the Shark Trust, campaign to limit shark fishing.-----------------------------------------------------------Dolphins are aquatic mammals related to whales and porpoises. The name is from Ancient Greek δελφίς delphis meaning "with a womb", viz. "a 'fish' with a womb". A group of dolphins can be called a "school" or a "pod".The word is used in a few different ways. It can mean:Any member of the family Delphinidae (oceanic dolphins), Any member of the families Delphinidae and Platanistoidea (oceanic and river dolphins), Any member of the suborder Odontoceti (toothed whales; these include the above families and some others), Used casually as a synonym for Bottlenose Dolphin, the most common and familiar species of dolphin. In this article, the second definition is used.Porpoises (suborder Odontoceti, family Phocoenidae) are thus not dolphins in this sense. Orcas and some related species belong to the Delphinidae family and therefore qualify as dolphins, even though they are called whales in common language.There are almost 40 species of dolphin in 17 genera. They vary in size from 1.2 m (4 ft) and 40 kg (88 lb) (Maui's Dolphin), up to 9.5 m (30 ft) and 10 tonnes (the Orca). Most species weigh about 50 to 200 kg (110 to 440 lb). They are found worldwide, mostly in the shallower seas of the continental shelves, and all are carnivores, mostly eating fish and squid.The family Delphinidae is the largest in the Cetacea, and relatively recent: dolphins evolved about 10 million years ago, during the Miocene.TaxonomySuborder Odontoceti, toothed whales Family Delphinidae, oceanic Dolphins Genus Delphinus Long-Beaked Common Dolphin, Delphinus capensis Short-Beaked Common Dolphin, Delphinus delphis Genus Tursiops Bottlenose Dolphin, Tursiops truncatus Indo-Pacific Bottlenose Dolphin, Tursiops aduncus Genus Lissodelphis Northern Rightwhale Dolphin, Lissodelphis borealis Southern Rightwhale Dolphin, Lissiodelphis peronii Genus Sotalia Tucuxi, Sotalia fluviatilis Genus Sousa Indo-Pacific Hump-backed Dolphin, Sousa chinensis Chinese White Dolphin (the Chinese variant), Sousa chinensis chinensis Atlantic Humpbacked Dolphin, Sousa teuszii Genus Stenella Atlantic Spotted Dolphin, Stenella frontalis Clymene Dolphin, Stenella clymene Pantropical Spotted Dolphin, Stenella attenuata Spinner Dolphin, Stenella longirostris Striped Dolphin, Stenella coeruleoalba Genus Steno Rough-Toothed Dolphin, Steno bredanensis Genus Cephalorynchus Chilean Dolphin, Cephalorhynchus eutropia Commerson's Dolphin, Cephalorhynchus commersonii Heaviside's Dolphin, Cephalorhynchus heavisidii Hector's Dolphin, Cephalorhynchus hectori Genus Grampus Risso's Dolphin, Grampus griseus Genus Lagenodelphis Fraser's Dolphin, Lagenodelphis hosei Genus Lagenorhyncus Atlantic White-Sided Dolphin, Lagenorhynchus acutus Dusky Dolphin, Lagenorhynchus obscurus Hourglass Dolphin, Lagenorhynchus cruciger Pacific White-Sided Dolphin, Lagenorhynchus obliquidens Peale's Dolphin, Lagenorhynchus australis White-Beaked Dolphin, Lagenorhynchus albirostris Genus Orcaella Australian Snubfin Dolphin, Orcaella heinsohni Irrawaddy Dolphin, Orcaella brevirostris Genus Peponocephalia Melon-headed Whale, Peponocephalia electra Genus Orcinus Killer Whale, Orcinus orca Genus Feresa Pygmy Killer Whale, Feresa attenuata Genus Pseudorca False Killer Whale, Pseudorca crassidens Genus Globicephala Long-finned Pilot Whale, Globicephala melas Short-finned Pilot Whale, Globicephala macrorhynchus Family Platanistoidea, River Dolphins Genus Inia Boto (Amazon River Dolphin), Inia geoffrensis Genus Lipotes Chinese River Dolphin (Baiji), Lipotes vexillife Genus Platanista Ganges River Dolphin, Platanista gangetica Indus River Dolphin, Platanista minor Genus Pontoporia La Plata Dolphin (Franciscana), Pontoporia blainvillei Six animals in the family Delphinidae are commonly called "whales" but are strictly speaking dolphins. They are sometimes called "blackfish":Melon-headed Whale, Peponocephalia electra Killer Whale, Orcinus orca Pygmy Killer Whale, Feresa attenuata False Killer Whale, Psudoorca crassidens Long-finned Pilot Whale, Globicephala melas Short-finned Pilot Whale, Globicephala macrorhynchus Hybrid DolphinsIn 1933, three strange dolphins were beached off the Irish coast; these appeared to be hybrids between Risso's Dolphin and the Bottlenose Dolphin. This mating has since been repeated in captivity and a hybrid calf was born. In captivity, a Bottlenose Dolphin and a Rough-toothed Dolphin produced hybrid offspring. In the wild, Spinner Dolphins have sometimes hybridised with Spotted Dolphins and Bottlenose Dolphins. In the wild, bands of males of one dolphin species have been observed to mate with lone female Spinners. Blue Whales, Fin Whales and Humpback Whales all hybridize in the wild. Dall's Porpoises and Harbour Porpoises have hybridized in the wild. There has also been a reported hybrid between a beluga and a narwhal. See also wolphin.Evolution and anatomy of dolphinsDolphins, along with whales and porpoises, are descendants of land-living mammals, most likely of the Artiodactyl order. Modern dolphin skeletons have two small rod shaped pelvic bones thought to be left-over hind legs. They entered the water roughly 50 million years ago. See evolution of cetaceans for the details.Dolphins have a fusiform body, adapted for fast swimming. The head contains the melon, a round organ used for echolocation. In many species, the jaws are elongated, forming a distinct beak; for some species like the Bottlenose, there is a curved mouth that looks like a fixed smile. Teeth can be very numerous (up to 250) in several species. The dolphin brain is large and has a highly structured cortex, which often is referred to in discussions about their high intelligence.Their teeth are arranged in a way that works as an array or antenna focusing the incoming sound, making it easier for them to pinpoint the exact location of an object.The basic coloration patterns are shades of gray with a light underside and a distinct dark cape on the back. It is often combined with lines and patches of different hue and contrast. See individual species articles for details.Dolphin behaviorDolphins in balance.Dolphins are widely believed to be amongst the most intelligent of all animals. A typical statement would be that dolphins are roughly as intelligent as a two-year-old human. However, experts in comparative psychology or animal cognition would be reluctant to make any such estimate, as quantitative comparisons of intelligence between species are notoriously difficult to make in principle. Straightforward comparisons of species' relative intelligence are complicated by differences in sensory apparatus, response modes, and nature of cognition; furthermore, the difficulty and expense of doing experimental work with a large marine animal mean that even such tests as can meaningfully be done have still not been done, or have been carried out with inadequate sample size and methodology. See the Dolphin intelligence article for more details.Dolphins often leap above the water surface, sometimes performing acrobatic figures (e.g. the spinner dolphin). Scientists aren't quite certain about the purpose of this behavior, but it may be to locate schools of fish by looking at above water signs, like feeding birds. They could also be communicating to other dolphins to join a hunt, attempting to dislodge parasites, or simply doing it for fun. Play is a very important part of dolphins' lives and they can often be observed playing with seaweed or playfighting with other dolphins. They have even been seen harassing other creatures, like seabirds and turtles. Dolphins also seem to enjoy riding waves and are frequently seen 'surfing' coastal swells and the bow waves of boats.They are also famous for their willingness to occasionally approach humans and playfully interact with them in the water. In return, in some cultures like in Ancient Greece they were treated with welcome; a ship spotting dolphins riding in their wake was considered a good omen for a smooth voyage. There are many stories of dolphins protecting shipwrecked sailors against sharks by swimming circles around the swimmers. A school of dolphins is also said to have pushed a fishing boat which was returning, back out to sea after sensing the underwater disturbances generated by the 2004 Asian TsunamiDolphins surfing at Snapper Rocks, Queensland, Australia.Dolphins are social animals, living in pods (also called "schools") of up to a dozen animals. In places with a high abundance of food, schools can join temporarily, forming an aggregation called a superpod; such groupings may exceed 1000 dolphins. The individuals communicate using a variety of clicks, whistles and other vocalizations. They also use ultrasonic sounds for echolocation.Membership in schools is not rigid; interchange is common. However, the animals can establish strong bonds between each other. This leads to them staying with injured or ill fellows for support.Because of their high capacity for learning, dolphins have been employed by humans for any number of purposes. Dolphins trained to perform in front of an audience have become a favorite attraction in dolphinaria, for example SeaWorld. Dolphin/Human interaction is also employed in a curative sense at places where dolphins work with autistic or otherwise disabled children. The military has employed dolphins for various purposes from finding mines to rescuing lost or trapped persons. Such military dolphins, however, drew scrutiny during the Vietnam War when rumors circulated that dolphins were being trained to kill Vietnamese Skin Divers.Reports of cooperative human-dolphin fisheries date back to Pliny. A modern human-dolphin fishery was reported in Laguna, Santa Catarina, Brazil in 1990. The transmission of this behavior appears to be matrilineal.In May 2005, researchers in Australia discovered a cultural aspect of dolphin behaviour: Some dolphins (Tursiops aduncus) teach their offspring to use tools. The animals break off sponges and put them onto their mouths thus protecting the delicate body part during their hunt for fish on the seabed. Unlike the sharing among all of the group by simian primates, dolphins mosly hand their knowledge of how to use a tool from mothers to daughters. The technology to use sponges as mouth protection is not genetically inherited but a taught cultural behaviour.Compare also: whale behaviorSensesMost dolphins have acute eyesight both in and out of the water and their sense of hearing is superior to that of humans. Though they have a small ear opening on each side of their head it is believed hearing underwater is also if not exclusively done with the lower jaw which conducts the vibrations to the middle ear via a fat filled cavity in the lower jaw bone. Hearing is also used for echolocation which seems to be an ability all dolphins have. The dolphin's sense of touch is also well-developed.However, dolphins lack an olfactory nerve and thus have no sense of smell, but they can taste and do show preferences for certain kinds of fish. Since dolphins spend most of their time below the surface in the wild, just tasting the water could act in a manner analogous to a sense of smell.FeedingDolphins are predators, chasing their prey at high speed. The dentition is adapted to the animals they hunt: Species with long beaks and many teeth forage on fish, whereas short beaks and lesser tooth count are linked to catching squid. Some dolphins may take crustaceans. Usually, the prey is swallowed whole. The larger species, especially the orca, are capable of eating marine mammals, even large whales. There are no known reports of cannibalism amongst dolphins.Individual species may employ a number of methods of hunting:Herding - where a superpod will control a school of fish while individual members take turns plowing through the herd, feeding. Corralling - where fish are chased to shallow water where they are more easily captured. Fish Wacking - where the dolphin uses its fluke to strike the fish, stunning it and sometimes sending it clear out of the water. Stunning - using the echolocation melon, very loud clicks are directed at prey, stunning them. Foraging - A recent study reported that wild bottlenose dolphins (Tursiops) in Western Australia use sponges to forage in the sea bed for food.[1] Mudding - Coastal bottlenose dolphins in South Carolina have been observed to drive fish onto mud banks and retrieve them from there. [edit]Dolphin loreThe popular television show Flipper, created by Ivan Tors, portrayed a dolphin in a friendly relationship with two boys, Sandy and Bud; a kind of sea going Lassie, Flipper understood English unusually well and was a marked hero: "Go tell Dad we're in trouble, Flipper! Hurry!" The show's theme song contains the lyric no one you see / is smarter than he. The television show was based on a 1963 film, and remade as a feature film in 1996 starring Elijah Wood and Paul Hogan (actor), as well as a television series running from 1995-2000 starring Jessica Alba. In The Hitchhiker's Guide to the Galaxy, dolphins are the second most intelligent creatures on Earth (after mice) and tried in vain to warn humans of the impending destruction of the planet. However, their behavior was misinterpreted as playful acrobatics. Their story is told in So Long, and Thanks for All the Fish. See Races and Species in The Hitchhiker's Guide to the Galaxy After study at the Dolphins Plus research center in Key Largo, Florida, fantasy author Ken Grimwood wrote dolphins into his 1995 novel Into the Deep, including entire chapters written from the viewpoint of his dolphin characters. A science fiction trilogy, "The Dolphins' View," is ghost written by Mookeeo, the main dolphin character. The story presents the fun loving nature of dolphins while they are also on a quest to save their world. Ecco the Dolphin stars in a series of games for the Sega Genesis/Mega Drive, Game Gear, Sega Dreamcast and PlayStation 2. A book called The Music of Dolphins was written by Karen Hesse, about a girl who had lived with dolphins since the age of four. An American National Football League (NFL) team is named the Miami Dolphins. Their logo depicts an aqua-colored bottlenose dolphin wearing an American football helmet and jumping in front of a coral-colored sunburst. In the Mystery Science Theater 3000 episode "Devil Fish," Mike and the 'Bots mock dolphins. While doing so, their craft, the Satellite of Love, gets blasted by a ship that turns out to be piloted by dolphins. Mike and the 'Bots then quickly apoligize. In seaQuest, Darwin the dolphin could communicate with English speakers using a vocoder, an invention that translated the clicks and whistles to English and back. In The Life Aquatic with Steve Zissou, marine researcher Zissou (played by Bill Murray) has trained reconnaissance dolphins which apparently are temperamental and rarely follow their instructions. In one scene, the dolphins' misbehavior elicits the following quote from Zissou: "Son of a bitch, I'm sick of these dolphins."In the book Startide Rising by author David Brin, the spaceship Streaker is manned by neo-dolphins (dolphins genetically engineered to match human intelligence). One of the mates of the ship is named Akeakamai, in honor of the real-life dolphin from Louis Herman's animal language research. In the William Gibson short story Johnny Mnemonic and the film by the same name (starring Keanu Reeves), cyborg dolphins were used in war-time by the military to find submarines and, after the war, by a group of revolutionaries to decode encrypted information. In the novel, The Old Man and the Sea, by Ernest Hemingway, the old man, on his second day of fishing, encountered and caught a gold dolphin with purple spots.

Sharks have a skeleton made of cartilage and dolphins have a skeleton made of bone.Sharks have gills and extract oxygen from water (as fish have a tendancy to do) and dolphins have to go to the surface and breath air (as mammals do).Also, Sharks play hockey (and make it to the playoffs) and Dolphins play football.

Then look it up and make your chart!! Is this how you plan on getting through the rest of your life? Do something for yourself. You might enjoy a sense of accomplishment.

Are you joking?!!!!!!!!!! Dolphins are sweet. ANd sharks aren't!

Mammals vs. FishMammals give birth to live young and suckle themGuessing sharks like all other fish are cold bloodedMammals breathe through lungs, fish through gills

dolphins is nice and sharks is not.