Research and presentation done by: Amihan Arroyo, Anneka Christie, and Alex Lopez

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Horn Sharks and Swell Sharks Behavior and
Interactions

• Research and presentation done by Amihan Arroyo,
  Anneka Christie, and Alex Lopez

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Our Research Project

• Observing the Horn Shark and Swell Shark in the
  touch tank on campus
• We wanted to see whether or not the amount of
  physical activity of both sharks changed due to
  time of day.
• Also, if they displayed different social
  behaviors at day or night.
• Our research question Do the sharks in the tanks
  social interactions with other organisms change
  during different hours of the day?

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The Swell Shark

• Cephaloscyllium ventriosum
• Habitat and Region Prefers kelp forests, caves,
  rock crevices and bottoms in order to hide. Found
  around the southern tip of Mexico, along
  Californias coasts, and in the Eastern Pacific.
• Diet crustaceans and fish
• Size Can grow up to 3 feet
• When the swell shark feels threatened, it
  swells up to twice its body size.

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The Horn Shark

• Heterodontus francisci
• Habitat and Range The Horn Shark lives in kelp
  forests and other habitats similar to the swell
  shark. This species can be found from Central
  California to Baja California
• Diet mollusks, crustaceans, small fish, sea
  urchins
• Size Can grow up to 4 feet
• The horns before each of their dorsal fins are
  actually spines.

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Our Hypothesis

• We believe that the sharks in the touch tank
  will be more active during the night time. This
  is because we have background knowledge that both
  species of sharks are nocturnal animals.
• We are also curious to see which behaviors they
  exhibit during these hours, and which organisms
  they interact with.

Horn Shark
Swell Shark
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Procedures

• Observed the sharks at touch tank for 15 minute
  intervals.
• Wrote down detailed observations about their
  activity.
• Logged and organized collected information daily

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Controls and Variables

• Controls
• Sharks in tank (amount and species)
  
• 15 minutes observations in a controlled habitat
• Variables
• time of day (independent)
• sharks activity and location (dependent)
• External Factors
• Feeding times
• Unnatural lighting
• Veterinarian arrived on 6/28 between 900a.m.-
  1230p.m.

• Due to the fact that our project was mostly
  observational, we didnt have many controls or
  variable present in our research.

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Observations

• We concluded that both sharks were significantly
  more active at night. This means that our
  hypothesis was correct.
• We also noticed that both sharks had very
  different behavioral systems. The Swell Shark was
  a lot more tolerant of other organisms, while the
  Horn Shark was easily disturbed by other animals.
  
• While the Horn Sharks activity slightly
  increased at night, it never reached the same
  level of activity as the Swell Shark.

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Why study this topic?

• Significance
• We decided to research this particular project
  because we were looking forward to learning more
  about these species. We hope our research will
  help scientists to study these sharks in
  captivity.

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Things We Can Change

• To extend this experiment

• For night observations, determine if the presence
  of light effected their behavior.
• Research in their natural environment.
• Study sharks of different age and gender to
  reflect the whole species.
• Study how sharks of the opposite sex interact
  with each other at different times during mating
  seasons.

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Acknowledgements

• Special thanks to
• Linda Chilton for all of her great help, support,
  and knowledge
• USC WIES, C DEBI, Sea Grant, and Staff for this
  amazing opportunity
• Kellie Spafford ( Marine Lab Technician) for
  answering all of our questions above and beyond
• Mason Clark (seasonal lab assistant) for helping
  us find information about the sharks
• Cleveland Richardson for helping us research for
  credible sources
• (a.k.a. book finder)

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Bibliography
Castro, Jose Ignacio. The Sharks of North
American Waters. College Station, TX Texas AM
UP,1996. Print. Russo, Ron. Pacific Coast Fish
A Guide to Marine Fish of the Coast of North
America. Berkeley, CA Nature Study Guild, 1990.
Print. https//www.montereybayaquarium.org.
"Swell Sharks., Cephaloscyllium ventriosum.
Monterey Bay Aquarium. N.p., n.d. Web. 28 June
2013. https//www.montereybayaquarium.org. "Horn
Shark." , Kelp Forest, Fishes, Heterodontus
Francisci. N.p., n.d. Web. 28 June 2013.
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Questions?

• Thank You!!
• We hope our presentation didnt make you do this