von Bertalanffy curve using observed lengths at age 

 produced an estimated age at L^ for the Gulf 

 sample of 28 years, and 37 years for the Atlantic 

 sample. This would mean that the species matures 

 at 30-50% of its maximum age, and with a reproduc- 

 tive cycle of greater than 2 years, a female would 

 reproduce less than 10 times. On the other hand, 

 von Bertalanffy curves derived using back- 

 calculated lengths at age for both samples produced 

 estimated ages at L^ of 45-50 years. Exceptional- 

 ly high ages at L^ may be due to the exponential 

 function of the model, or it is also possible that as 

 tiger sharks attain sizes near their maximum weight 

 or length, centrum growth and band formation do 

 not accurately represent age. Because no excep- 

 tionally large individuals were aged, we are unable 

 to determine which is the case. Even so, the data 

 indicate that the tiger shark is long-lived with a 

 relatively low fecundity, and natural mortality for 

 the young may be high. As with many other elasmo- 

 branchs, this combination of /^'-selected character- 

 istics may result in an overexploitation of this 

 species under increased recreational and commer- 

 cial fishing pressure (Musick and Colvocoresses 

 1986). 



ACKNOWLEDGMENTS 



Appreciation is extended to commercial longline 

 vessel owners and captains (Hollis Forrester, Bill 

 Templeton, Lacy Smith, Arnold Davila, Olin Wel- 

 born. Buddy and Tinker Lindley, Joe Gayman, 

 Henry Jones, and Floyd Condit), Mark's Sharks, 

 Inc., the Biggs Pensacola Shark Rodeo, the Dauphin 

 Island Deep Sea Rodeo, the Galveston Monster 

 Fishermen Club Shark Tournament, and the Vir- 

 ginia Beach Sharkers for allowing access to and ex- 

 amination of numerous tiger sharks. We thank 

 Marine Advisory Service personnel Gary Graham 

 and Tony Reisinger for their help during the course 

 of this study. Debbie Branstetter provided con- 

 tinuous laboratory and field assistance in the Gulf 

 of Mexico study, and John Gourley and Marta Nam- 

 mack provided invaluable aid in the Virginia pro- 

 gram. The senior author wishes to acknowledge the 

 support and encouragement provided by John D. 

 McEachran. 



Different portions of this study were supported 

 by the Gulf and South Atlantic Fishery Development 

 Foundation, Inc., the Texas A&M Sea Grant 

 College Program, the Virginia Sea Grant Program, 

 the Graduate College and Association of Former 

 Students of Texas A&M University, and the State 

 of Texas. 



FISHERY BULLETIN: VOL. 85, NO. 2 



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