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Dolphins

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									         Dolphins

A Look At Dolphins for a 5th Grade
              Class
       By: Keith Innocenti
                 Dolphins

• Dolphins are mammals, not fish.
• They are warm blooded like man, and give birth
  to one baby at a time called a calf.
• At birth a dolphin calf is about 90-130
  centimeters long and can grow up to 4 meters.
• Dolphins live in groups called pods.
           The Dolphin’s Tail
• Dolphin’s tails are very powerful and can be
  used for many things.
• For Example: A dolphin will flap his tail in an
  up and down motion to move through the
  water.
• Other uses of the tail include hunting, stunning
  its prey, and slapping the water to warn other
  dolphins of danger.
         The Dolphin’s Teeth
• The Dolphin’s teeth are very sharp in order to
  grab a hold of slippery fish.
• They have the ability to eat whole fish and
  usually do it head first.
• In the wild an open mouth for a dolphin is a
  sign of aggression, as is head nodding.
• A sign of greater aggression is violent jaw
  clapping.
           The Dolphin’s Eyes
• The Dolphin’s eyes produce a slippery secretion
  that protects the eyes from foreign objects and
  water friction.
• When a dolphin sleeps it must shut down only
  half of its brain, as its breathing is under
  voluntary control.
• Dolphins are known to take very short cat-naps,
  floating just below the surface, then slowly rising
  to breathe.
        A Dolphin’s Breathing
• Dolphins breathe through their blowhole
  located at the top of their head.
• A Dolphin may empty and refill its lungs in less
  than a fifth of a second.
• As the dolphin breathes the air leaves the
  blowhole at speeds of over a 100 mph.
              The Blowhole
• Complex nerve endings around the blowhole
  sense pressure change so the dolphin knows
  exactly when the blowhole is in or nearing the
  air and can be opened.
• Water in a Dolphin’s blowhole will actually
  drown it, so powerful muscles close the
  blowhole as it dives under the water again.
           The Dolphin’s Skin
• The Dolphin’s skin is completely smooth
  allowing the dolphin to move easily through the
  water, and also reduce heat loss.
• Their skin may bear rake marks from other
  dolphins teeth during playing or mating, and can
  easily become badly sunburned if they strand.
• Their bodies are very streamlined so they may
  swim at high speeds through the water, an
  example of this is their ears.
               Great Depths
• Dolphin’s are able to dive to great depths, and
  also leap to great heights.
• They may use their leaping ability to avoid
  predators in the water or to show how powerful
  they are to females during mating time.
• Bottlenose dolphins can dive to depths of over
  1,640 feet (500m).
Body Parts of a Dolphin
               Food Intake
• Adult bottlenose dolphins eat approximately 4%
  to 5% of their body weight in food per day.
• Their stomach is made for rapid digestion.
• Dolphins eat a variety of fishes, squids, and
  crustaceans such as shrimps. The foods
  available to dolphins vary with its geographic
  location.
             Life Expectancy
• The average life expectancy for a bottlenose
  dolphin is around 20 years. However, there
  have been cases of bottlenose dolphin’s living
  past 40.
• As A dolphin ages, it periodically produces
  growth layer groups of dental material. Age is
  estimated by examining a sliced section of a
  tooth and counting its layers.
Pictures Of Dolphin’s

								
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