470 
PACIFIC SCIENCE, VoL XX, October 1966 
Elowever, there was a difference in their re- 
sponse to punishment. While undergoing train- 
ing, blacktips frequently displayed hypersensi- 
tive and erratic behavior, while grey sharks did 
not deviate much from their normal swimming 
pattern. This may reflect a real difference in nor- 
mal behavior. Hobson (1963) found that 
blacktips were much more wary than grey 
sharks in their natural environment. 
ACKNOWLEDGMENTS 
We are indebted to the Department of the 
Navy, Office of Naval Research, for financial 
support (Contract Nonr-2756(00), project 
NR 104-503), to the Atomic Energy Commis- 
sion for funds to construct special shark tanks, 
and to both AEG and the Department of the 
Navy, Pacific Missile Range, for logistic and 
other support. Facilities, supplies, and transpor- 
tation were made available by Dr. R. W. Hiatt, 
Director, Eniwetok Marine Biological Labora- 
tory. We also wish to acknowledge the help of 
Mr. Taylor A. Pryor, graduate student of the 
University of Hawaii, in preliminary experi- 
mentation. 
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