Abstract. — We examined 1,469 

 tarpon, Megalops atlanticus, ranging 

 from 102 to 2,045 mm fork length (FL) 

 collected in South Florida waters from 

 1988 to 1993. Females had a mean 

 length of 1,677 mm FL (n=322) and 

 were significantly larger than males, 

 which had a mean length of 1,447 mm 

 FL (n=125). Ages of 977 tarpon were 

 estimated from thin-sectioned otoliths 

 (sagittae). Eighteen tarpon were 

 marked with oxytetracycline (OTC) to 

 form a reference point on the otolith 

 and were held in captivity for periods 

 ranging from 13 to 50 months. Exami- 

 nation of OTC-marked otoliths sug- 

 gested that a single annulus was 

 formed each year. Marginal increments 

 of young of the year and 1-year-old tar- 

 pon showed a single annual minimum 

 during April-June. Tarpon are long- 

 lived and reach a maximum age of at 

 least 55 years. Growth of the tarpon in 

 our study was rapid until an age of 

 about 12 years and then slowed consid- 

 erably. Male tarpon (rc = 141) ranged 

 from to 43 years in age, and female 

 tarpon (rc=298) ranged from to 55 

 years in age. The von Bertalanffy 

 growth equation for females was FL = 

 1,818( l _ e <-o-io3iA*M-i.4io») and for males 



was FL = 1,567(1 -e'- 01231 ^" 157511 ). Es- 

 timates of the von Bertalanffy growth 

 parameters L_ and K for males and fe- 

 males were significantly different. Pre- 

 dicted lengths of females were greater 

 than those of males for all ages greater 

 than 4 years. 



Age and growth of tarpon, 



Megalops atlanticus, 



from South Florida waters* 



Roy E. Crabtree 



Florida Marine Research Institute, Department of Environmental Protection 

 100 Eighth Avenue SE, St. Petersburg, Florida 33701-5095 



Edward C. Cyr 



Office of Protected Resources, National Marine Fisheries Service 

 1335 East-West Highway, Silver Spring, Maryland 20910 



John M. Dean 



Institute of Public Affairs, University of South Carolina 

 Columbia, South Carolina 29208 



Manuscript accepted 24 April 1995. 

 Fishery Bulletin 93:619-628 (1995). 



Tarpon, Megalops atlanticus, are 

 large, migratory, elopomorphic fish 

 that frequent coastal and inshore 

 waters of the tropical and subtropi- 

 cal Atlantic Ocean. In the western 

 Atlantic, tarpon regularly occur 

 from Virginia's eastern shore to 

 Central Brazil and throughout the 

 Caribbean Sea and the Gulf of 

 Mexico (Wade, 1962; Hildebrand, 

 1963; de Menezes and Paiva, 1966; 

 Zale and Merrifield, 1989). In South 

 Florida and parts of Central America, 

 tarpon are the basis of economically 

 important recreational fisheries. In 

 Florida, the fishery is intensely 

 regulated, and anglers are required 

 to purchase a permit before harvest- 

 ing a fish. Since the establishment 

 of the permit system in 1989, the 

 harvest of tarpon in Florida has 

 declined to less than 100 fish per 

 year, and the fishery is now mostly 

 catch-and-release. Tarpon occur in 

 a variety of habitats ranging from 

 freshwater lakes and rivers to off- 

 shore marine waters, but large tar- 

 pon targeted by Florida's fishery are 

 most abundant in estuarine and 



coastal waters. In Florida, the fish- 

 ery is seasonal; most tarpon are 

 caught during May^July, although 

 some fish are caught in all months. 

 Tarpon life history has not been 

 adequately described. Breder ( 1944) 

 examined gonads of tarpon from 

 Florida waters but did not fully de- 

 scribe either temporal spawning 

 patterns or age and size at sexual 

 maturity. De Menezes and Paiva 

 (1966) macroscopically examined 

 gonads of tarpon from Brazilian 

 waters and reported on temporal 

 spawning patterns and size at 

 sexual maturity. Most information 

 on tarpon reproduction in Florida 

 waters has been inferred from early 

 life history studies (Smith, 1980; 

 Crabtree et al., 1992; Crabtree, 

 1995). Larval distribution patterns 

 suggest that tarpon in Florida wa- 

 ters spawn offshore from May 

 through August (Smith, 1980; Crab- 



* Contribution 1054 of the Belle W. Baruch 

 Institute for Marine Biology and Coastal 

 Research, University of South Carolina, 

 Columbia, SC. 



619 



