DOLPHINS

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DOLPHINS

• By
• (5th Grade)

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Biome

• Dolphins live in the Aquatic Biome.
• This biome can be broken down into two basic
  regions Freshwater and Marine
• The bottlenose dolphin is found worldwide in
  tropical and temperate marine ocean waters.
• The largest of all the ecosystems, oceans are
  very large bodies of water that dominate the
  Earths surface.

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Biome

• Bottlenose Dolphins live in the pelagic zone of
  the ocean, which includes those waters further
  from the land, basically the open ocean.
• The pelagic zone is generally cold.

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Biome

• The flora in the pelagic zone include surface
  seaweeds. The fauna include many species of fish
  and some mammals, such as whales and dolphins.
• Many feed on the abundant plankton.

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Habitat

• Bottlenose dolphins are found from northern Japan
  and California to Australia and Chile and in
  worldwide oceans.
• Bottlenose Dolphins can be found in harbors,
  bays, lagoons, gulfs, and estuaries.

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Food Chain

• Tiger, Bull and Dusky Sharks are the main
  predators. They also get caught in fishermens
  nets as they fish for tuna.
• Dolphins are hunters and they mainly eat fish and
  squid.
• They hunt near the surface of the water.

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Interesting Facts

• Dolphins are not fish they are considered
  mammals.
• They breathe air directly into their lungs.
• They are warm-blooded.
• They give birth to live young.
• They are like small whales, and can swim more
  than 25 miles per hour.
• They have 94 teeth and they travel in groups
  called pods.

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Bottlenose DolphinBehavior

• They are known for their playful behavior.
• They can jump 20 feet.
• When hunting they chase fish toward shallow
  water.
• They corral schools of fish and take turns
  swimming into the school to feed.
• Watch this video.

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Bottlenose DolphinBehavior
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Structure and Function

• Stream-lined bodies and a rounded head with a
  distinctive beak.
• They have a tall, falcate (sickle-shaped) dorsal
  fin and broad, slightly pointed flippers.
• Use their tail flukes when hunting, by hitting a
  fish up into the air with their tail, stunning
  it, then scooping the fish up when it falls back
  into the water.

• Melon is fatty and helps direct sound.

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Communication

• Dolphins use snaps and whistles to warn other
  dolphins of predators.

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Adaptations to Survive

• Bottlenose dolphins have a layer of blubber under
  their skin to keep warm.
• During a deep dive (up to 1000 feet) their lungs
  and ribs partially collapse.
• They store oxygen in their blood and muscles
  instead of their lungs.

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Evolution

• Inside their pectoral fins, dolphins have a
  skeletal structure similar to a human arm and
  hand.
• They have a humerus with a ball and socket joint.
  
• They have a radius and ulna, as well as a
  complete hand structure, including five finger
  bones.
• This makes scientists think dolphins evolved from
  a terrestrial ancestor.

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Evolution
Diagram of a dolphin dorsal fin bone structure
and a human arm and hand bone structure.
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Life Cycle

• Bottlenose dolphins breed in early March to mid
  May.
• Baby dolphins grow to an adult dolphin and then
  reproduce.
• Dolphins can live up to
• twenty five years
• in the wild.

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Reproduction

• When dolphins mate, they don't really get
  married.
• They just swim belly to belly for about 30
  seconds.
• The average time a calf grows inside a mother is
  about 10-12 months.
• Calves have to be born tail first otherwise they
  will probably drown before they are able to fully
  come out of their mother.

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Reproduction

• After the two dolphins mate and have their baby,
  they part, and the mother dolphin takes care of
  the baby by herself.

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Babies

• When they are born, dolphins have whiskers on
  their rostrum.
• A dolphins whiskers are about one quarter inch
  long, and will fall out after birth, because of
  water pressure.
• Babies stay with their mom 3-6 years.

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Human Impact

• Bottlenose dolphins have been
• caught for meat, leather, oil, and
• meal (for fertilizer and animal feed).
• Are affected by pollution, heavy boat traffic,
  habitat destruction, and competition for schools
  of fish by fisheries.
• Caught accidentally in fishing nets. Recent
  conservation efforts have greatly reduced the
  number of dolphin deaths. But scientists believe
  that actual deaths may be more than reported.

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References

• Photos used with permission and retrieved from
  http//www.pics4learning.com
• Video used with permission and retrieved from
• http//www.nationalgeographic.com/kids/creature_fe
  ature/0108/dolphins2.html
• Facts
• http//www.dolphins.org/Learn/lmm-phys.htm
• http//www.enchantedlearning.com/subjects/whales/
• species/Bottledolphin.shtml
• http//www.aqua.org/downloads/pdf/Dolphins.pdf
• Kovacs, Deborah. All About Dolphins! Bridgeport,
  Connecticut Third Story Books, 1994.
• Gay, Tanner Ottley. Whales and Dolphins in
  Action. New York Aladdin Books, 1991.