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Island of the Sharks
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Ask The Expert
Set 2, posted September 25, 1998
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Question:

Do sharks have emotions? It seems to me that mammals are far more emotional creatures then fish, reptiles and insects.

(name witheld by request)



Response from Dr. Klimley:

Emotion is defined in Webster's New World Dictionary as "any specific feeling: any of various complex reactions with both mental and physical manifestations, as love, hate, fear, anger, etc." Each human attribute must be objectively defined as an external manifestation before we can determine whether an animal possesses one. With humans, we can detect an emotion such as anger by the raising of the voice or the lifting of one's fists in a show of threat.

Sharks do not have vocal chords and can not communicate anger by raising their voice. Female hammerhead sharks do chase smaller and less strong sharks from the center of schools by performing a threat consisting of reverse flip and full twist in diving parlance. White sharks frighten competitors away from a seal carcass by lifting the tail out out of the water and propelling a sizable splash in the direction of the other. However, we can not know whether these behaviors may be an outward manifestion of anger.



Question:

What do you think could be the most important things that we could learn about the great white shark as far as behavior, habits, range, etc. Thanks.

(name witheld by request)



Response from Dr. Klimley:

One theory explains much white shark behavior that in the past has been enigmatic. White sharks seize humans, yet often release them without removing a bite. I have proposed that the species has a preference for energy-rich fat, and for this reason, it eats seals, sea lions, and whale blubber, which are rich in fat, but spits out birds, sea otters, and humans, that are very lean. The reason why these sharks are so selective in what they eat is that they dwell in cold waters. They may need this extra energy to keep their body temperature elevated, warm their eyes, and brains so that they can successfully chase and capture marine mammals. Of course, the marine mammals have evolved a fatty layer to keep them warm in cold waters and suffer the consequence in being the favored prey of adult white sharks.



Question:

How long have you been working in the field of shark research? Do you enjoy it?

(name witheld by request)



Response from Dr. Klimley:

I entered the Master's degree program at the University of Miami's Rosenstiel School of Marine and Atmospheric Sciences fall of 1973. For the next three and a half years, I studied how sharks were attracted to prey based upon the sounds they emit and how sharks were frightened by sudden looud sounds. My career as an animal behaviorist interested in sharks and other large fishes as stretched over 25 years. I love the work and hope to continue it for another 25 years.





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