Abstract. — We sampled jewfish 

 from recreational and commercial 

 catches in the eastern Gulf of Mex- 

 ico from November 1977 to January 

 1990 to obtain life history informa- 

 tion. A single annual minimum in 

 mean marginal increment ratios dur- 

 ing May- August supported the hy- 

 pothesis that jewfish up to at least 

 age 10 can be aged by counting the 

 opaque marks observed on otolith 

 sections. Annual opaque mark for- 

 mation was observed for a 3- and a 

 4-year-old jewfish using oxytetracy- 

 cline (OTC) reference marks on oto- 

 liths (sagittae). Male jewfish (A'' 41) 

 ranged 3-26 years old; females, 0-37 

 years (A'^ 85). Growth was similar for 

 males and females, averaging >100 

 mm/year through age 6, then slow- 

 ing to about 30 mm/year by age 15, 

 and finally declining to < 10 mm/year 

 after age 25. Observed total length 

 and age data were described well by 

 the following von Bertalanffy growth 

 model: total length (mm) = 2006 



(1 



3(-0.126 



(age(yrs) + 0.49)))_ Jgwfish 



spawned from June through Decem- 

 ber, with peak activity from July 

 through September. Male jewfish 

 matured at about 1100-1150mm 

 when 4-6 years old; females matured 

 at 1200-1350 mm when 6 or 7 years 

 old. The extensive overlap of length 

 and age distributions of males and 

 females, and the slight differences 

 between their sizes and ages at ma- 

 turity, prevent us from designating 

 jewfish as a protogynous herma- 

 phrodite. No transitional individuals 

 were found. Their relatively slow 

 growth, longevity, and behavioral 

 characteristics, such as the tenden- 

 cy to form spawning aggregations, 

 make jewfish populations highly sus- 

 ceptible to overfishing. 



Age, growth, and reproduction of 

 jewfish Epinephelus itajara in 

 the eastern Gulf of Mexico 



Lewis H. Bullock 



Michael D. Murphy 



Florida Marine Research Institute, Florida Department of Natural Resources 

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



Mark F. Godcharles 



Southeast Region, National Marine Fisheries Service, NOAA 

 9450 Koger Boulevard, St. Petersburg, Florida 33702 



Michael E. Mitchell 



Florida Marine Research Institute, Florida Department of Natural Resources 

 1 481 -A Market Circle, Port Charlotte, Florida 33953 



Manuscript accepted 11 March 1992. 

 Fishery Bulletin, U.S. 90:243-249 (1992). 



The jevirfish Epinephelus itajara, 

 largest of the western North Atlan- 

 tic groupers (possibly reaching 455 

 kg; Robins et al. 1986), ranges from 

 the east coast of Florida throughout 

 the Gulf of Mexico, Caribbean Sea, 

 and south to Brazil (Smith 1971), and 

 also in the Pacific Ocean from Costa 

 Rica to Peru. Jewfish occur at depths 

 ranging from several meters (shallow 

 estuarine areas) to about 50 m. Juve- 

 niles can be found in holes and below 

 undercut ledges in swift tidal creeks 

 draining mangrove swamps. Large 

 adults occur both inshore around 

 structures such as piers and bridges, 

 and offshore around ledges and 

 wrecks (Bullock and Smith 1991). 



Jewfish have recently been granted 

 protected status, eliminating harvest 

 in both the U.S. Exclusive Economic 

 Zone (NMFS 1990a, b) and Florida's 

 territorial waters (Florida Marine 

 Fisheries Commission 1990). Prior to 

 this designation, jewfish were cap- 

 tured by hook-and-line, speargun, 

 shark and grouper/snapper longlines, 

 and as a bycatch of shrimp trawling. 

 Historically, the majority of the U.S. 

 commercial catch has been landed 

 along the Florida Gulf coast, where 

 landings reached a high of approx- 



imately 61,700 kg in 1988 (Fla. Dep. 

 Nat. Resour. Annual Landings Summ., 

 Fla. Mar. Res. Inst., St. Petersburg, 

 unpubl. data). 



A comprehensive study of jewfish 

 life history does not exist. Smith 

 (1971) discussed their systematics, 

 distribution, and ecology. Randall 

 (1967) described food habits from 

 nine individuals. Other researchers 

 have contributed incidental observa- 

 tions on diet (Beebe and Tee-Van 

 1928, Tabb and Manning 1961, Odum 

 1971), habitat (Smith 1976, Odum et 

 al. 1982), spawning (Schroeder 1924, 

 Colin 1990), and parasites/pseudo- 

 parasites (Breder and Nigrelli 1934, 

 Pearse 1934 and 1952, Manter 1947, 

 Olsen 1952). Bullock and Smith 

 (1991) provided basic life-history in- 

 formation on jewfish in the eastern 

 Gulf of Mexico, but did not dis- 

 cuss age and growth or size/age-at- 

 maturity. In this paper, we describe 

 age and growth, spawning seasonal- 

 ity, and approximate size- and age- 

 at-maturity for jewrfish in the east- 

 ern Gulf of Mexico. We also briefly 

 discuss the implications of these life- 

 history characteristics as they relate 

 to the jewfish's susceptibility to 

 overfishing. 



243 



