Abstract.- The red hind Ejnne- 

 phelus guttatics, a grouper of com- 

 mercial importance in the central 

 western Atlantic, is believed to be 

 overexploited in a number of areas. 

 Red hind taken by fish trap and 

 hook-and-line in western Puerto Rico 

 and the U.S. Virgin Island of St. 

 Thomas were aged using sectioned 

 otoliths (sagittae). Ages were vali- 

 dated by marginal increment analy- 

 sis for fish ages 1-10 yr, and by a 

 field study involving oxytetracycline 

 injection for fish ages 1-4; a single 

 opaque and translucent zone (viewed 

 under transmitted light) is deposited 

 annually. For Puerto Rico, the von 

 Bertalanffy growth function (VBGF) 

 was Lt=514.5 (i_e-»ioi(t+2.94)) 



Back-calculated mean fork lengths 

 ranged from 163 mm at age-1 yr, to 

 448mm at maximum age-17. For St. 

 Thomas, the VBGF was L, =601.0 



(1- 



-0 071(t+4.69) 



). Back-calculated 



mean fork lengths ranged from 194 

 mm at age-1, to 470 mm at maximum 

 age-18. Sex and stage of sexual 

 maturation were determined for a 

 subsample of aged fish from Puerto 

 Rico. Fifty percent of females had at- 

 tained sexual maturity by age 3 yr. 

 Ages of females were 1-9 yr; males, 

 2-17 yr, and individuals undergoing 

 sexual transition from female to 

 male, 3-7 yr. The male to female sex 

 ratio was 1:2.6. The occurrence of 

 sexually-transitional individuals, as 

 well as significant differences be- 

 tween the sexes in both size and age, 

 confirm protogynous hermaphrodit- 

 ism for fish from Puerto Rico. 



Age and growth of red hind 

 Epinephelus guttatus in 

 Puerto Rico and St. Thomas 



Yvonne Sadovy 

 Miguel Figuerola* 

 Ana Roman 



Fisheries Research Laboratory, Department of Natural Resources 

 P O Box 3665. MayagiJez, Puerto Rico 



The red hind Epinephelus guttatus is 

 a serranid of considerable commer- 

 cial importance throughout the 

 Caribbean, the Bahamas, and Ber- 

 muda (Burnett-Herkes 1975, Mahon 

 1987). In Puerto Rico and the U.S. 

 Virgin Islands, this species is one of 

 the most-frequently reported group- 

 ers in commercial landings. It is 

 taken by hook-and-line, fish trap, and 

 speargun, over the insular shelf to a 

 depth of about 80 m. 



Grouper are relatively long-lived 

 and slow-grovdng fishes. These char- 

 acteristics, combined with the proto- 

 gynous sexual pattern (female to 

 male sex change) reported for many 

 grouper, and intensive fishing over 

 short-term traditional spawning ag- 

 gregations, render grouper species 

 especially vulnerable to overexploita- 

 tion (Bannerot et al. 1987, Manooch 

 1987, Ralston 1987, Shapiro 1987, 

 Bohnsack 1989). 



There are indications that red hind 

 resources of Puerto Rico and the U.S. 

 Virgin Islands are being overex- 

 ploited. Commercial grouper land- 

 ings reported in Puerto Rico have 

 declined consistently and substantial- 

 ly over the last decade, from 386 mt 

 in 1978 to 47 mt (of which 38% were 

 red hind) in 1990 (Matos and Sadovy 

 1989, Sadovy In press, Sadovy and 

 Figuerola 1992). Yield-per-recruit 

 analyses indicate growth overfish- 

 ing (harvesting at too small a size to 

 maximize potential yield) in western 



Manuscript accepted 27 May 1992. 

 Fishery Bulletin, U.S. 90:516-528(1992). 



• Reprint requests should be addressed to this 

 author. 



Puerto Rico (Stevenson 1978, Sadovy 

 and Figuerola 1992). All known an- 

 nual spawning aggregations in both 

 Puerto Rico and St. Thomas are 

 heavily exploited. In addition, recent 

 length-frequency data from commer- 

 cial catches in St. Thomas indicate 

 that mean length declined substan- 

 tially between 1984 and 1988 (Beets 

 and Friedlander 1992), although it is 

 not clear to what extent this decline 

 is attributable to overfishing, or is 

 related to annual variation in recruit- 

 ment (Appeldoorn et al. 1992), or a 

 combination of the two. 



Little is known of the life history 

 of the red hind. Previous studies on 

 age and growth in this species have 

 been conducted in Bermuda using 

 whole otoliths (Burnett-Herkes 

 1975), and in Jamaica using length- 

 frequency analysis (Thompson and 

 Munro 1974). However, neither 

 study is recent and neither validated 

 the ageing techniques. The sexual 

 pattern is reported to be protogyny 

 in Bermuda (Smith 1959, Burnett- 

 Herkes 1975), and protogyny is also 

 indicated for Puerto Rico stocks 

 (Shapiro et al. unpubl. data). The ob- 

 jectives of this study were to deter- 

 mine age and growth of the red hind 

 in two heavily-exploited areas- 

 western Puerto Rico and St. Thomas, 

 U.S. Virgin Islands— and to confirm 

 sexual pattern. This information is 

 necessary to allow stock assessments 

 to be made for this species, and to 

 permit the development of a manage- 

 ment policy for the red hind in the 

 region. 



516 



