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Sharks and Rays. Class Chondrichythes. Common Rays in Hawaii. Fish vs. Sharks. Sharks are Fish!....But. Do not have bones 5-7 external gill openings No gill cover No swim bladder Internal fertilization with claspers Placoid scales. Form and Function. - PowerPoint PPT Presentation
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Sharks and RaysClass Chondrichythes
Common Rays in Hawaii
Fish vs. Sharks
Sharks are Fish!....ButDo not have bones5-7 external gill openingsNo gill coverNo swim bladderInternal fertilization with claspersPlacoid scales
Form and FunctionHeterocercal tail = upper lobe longer than the lowerStrengthen and support tail for forward thrust
Teeth in rowsTeeth lack roots and often breakEasily replaced
Placoid scalesReduce drag, protection
Paired Pectoral FinsAirplane wings, provide lift
Predominant dorsal finBalance
Sharks SEVEN SensesS SoundCan hear a fish 100 yards awayO OlfactionIn one nostril and out the otherL Lateral LineV VisionE ElectroreceptionT TouchT - Taste
ElectroreceptionSimilar to a metal detectorAmpullae of LorenziniDetects the magnetic field around living organismsOnly other animals with this sense: duck billed platypus and spiny anteater
Sharks in HawaiiAggressive Species
Tiger 18 ftGalapagos 10-12 ftHammerhead - 12-15 ftGreat White
Other SpeciesBlacktip 8 ftReef Black Tip 6 ftReef White Tip 6 ftSandbar - 5-6 ft
Shark Attacksnever swim alonedon't swim with open wounds or speared fishdon't swim erratically or make splashing noisesavoid the water at night - sharks hunt at nightavoid murky water - sharks may mistake you for a preydon't harass or provoke sharksif you witness fish behaving erratically, leave areaif you encounter a shark, remain calm and slowly leave area
Environmental ConcernsSharks are top predators
Keystone species that keep prey populations under control
Sharks extinct?Populations continue to decline
If fishing continues, could go extinct
18 species are threatened with extinction
Our Impact
Something to Think About~ 6 people killed by sharks a year~ 12 million sharks killed by humans
BycatchFisheries
Basic Fish Fin FunctionsDorsal fin - stability in swimming Pelvic fin - stability in swimmingCaudal fin - main propelling finAnal fin - stability in swimmingPectoral fins - Locomotion and side to side/ back forth movement.