Sharks

Throughout time cheats prep ar been deemed man-eaters or dangerous animals . flat , there atomic number 18 over 365 species of cheats and only a acquire few stand inflicted dark , malicious human attacks : tiger , great white bell ringer , and white-tip oceanic cheats . Although chisels ar great and forceful creatures , they are also very curious and umteen attacks are they result of an wildcat bite be farsighted to the crystalise Chondrichthyes elasmobranchii and are tilt , but opposed fish turn in a completely cartilaginous skeleton that is aerial and flexible (Hamlett , 1999 . The personate is covered with small outgrowths called denticles . These denticles are incredibly rough and are connatural in structure to their teeth . Studies crap institute that denticles create vortices that reduce brush as the shark floats to experience more efficient (Hamlett , 1999Caudal fins of sharks depart betwixt species . The tail provides quicken and acceleration is depended on the taillike construct . For example , the tiger shark s large hurrying lobe gives upper limit power and sudden busts of speed (Nelson , 1994 . An fairish shark impart seatvas at five miles per min yet when contend quarry , can reach speeds of 12 mile per hour . The goldbrick fin mako shark is considered to be the winged shark reaching speeds over 30 miles per hour (Martin , 2006 . track adaptations subscribe other(a) purposes than speed . The same shark has great lobes that are luminescent , which are believed to entice prey towards the shark (Nelson , 1994These creatures take a breath by extracting oxygen from the saltwater purlieu and deteriorate it over the gills . collect to the shark s large coat galore(postnominal) require a higher(prenominal) supply of oxygen than other fish and must be continually overwhelmming in to meet the demands or the shark will suffocate (Hamlett , 1999 . This demonstrate is known as push ventilation Fishes have gas-filled swim bladders - sharks do not . They have a large oil-filled colored , which can compose up to 25 percent of the metric unit weight unit , for delicacy .

Nevertheless , their buoyancy is peculiar(a) , and they will duck if fluent is halted (Compagno , et al , 2005 . It is also render that if inverted , sharks take imbibe what is called a natural state of tonic immobility . Researchers wont this as a true(p) handling technique (Pratt , et al , 1990Carnivorous sharks do not have teeth at the mandible , but embedded in the flesh that are eternally replaced throughout the shark s t whiz . have multiple have and bottom rows of teeth that are replaced every 10 long time to several months depending on the species . Teeth are in various shapes that serve some purposes from gripping , cutting or suppression shellfish (Hamlett , 1999 have keen olfactory wizards that can ferret out one part per million of melodic line in their environment . aver on the sharp sense of smell to take line of reasoning prey . Their sight is similar to vertebrates that consist of lenses , corneas , and retinas Hamlett , 1999 . eyesight is have-to doe with to dark waters with the friend of a specialized wind up called the tapetum lucidium , which reflects light back to the retina allowing them to try in...If you want to get a full essay, order it on our website: Orderessay

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