AGE AND GROWTH OF 



SPANISH MACKEREL, SCOMBEROMORUS MACULATUS , 



FROM FLORIDA AND THE GULF OF MEXICO 



William A. Fable, Jr., Allyn G. Johnson, and Lyman E Barger' 



ABSTRACT 



Otoliths from 1,787 Spanish mackerel, Scomberomorus maculatus , were used to estimate age and 

 growth rates of this species from Florida and the Gulf of Mexico. There was a wide range of lengths 

 within an age group: the oldest male was 7 years old, while the oldest female was 9 years old. Length 

 at age was significantly different for sexes, sampling areas, and collection gear. The von Bertalanffy 

 growth equations were as follows: males (all cireas combined) /, = 794 (1 - e~0.24« + 0.94); females (all 

 areas combined) /, = 739 (1 - e-0 33(< + 99); males (Florida only) If = 776 (1 - e-0.27(( + 0.73); females 

 (Florida only) /, = 731 (1 - e-0.38« + 0.73)^ where / = fork length (mm) and t = years. 



Spanish mackerel, Scomberomorus maculatus, 

 are found in the western Atlantic Ocean from the 

 Gulf of Maine to the Yucatan Peninsula (Collette 

 et al. 1978), and have their center of abundance 

 off Florida (Trent and Anthony 1978). They sup- 

 port extensive commercial and recreational fish- 

 eries in the U.S. south Atlantic and Gulf of Mex- 

 ico. In 1985, U.S. commercial landings totaled 5.8 

 million pounds (2,631 t) (U.S. Department of 

 Commerce 1986a) while recreational landings 

 were estimated to be 2.1 million pounds (953 t) 

 (U.S. Department of Commerce 1986b). Informa- 

 tion on Spanish mackerel published prior to 1978 

 actually concerned two species, .S . maculatus and 

 S. brasiliensis (Collette et al. 1978). Collette et 

 al. (1978) determined that Spanish mackerel 

 south of the Yucatan Peninsula (on the Cen- 

 tral and South American Atlantic coasts) are 

 S. brasiliensis, and those along U.S. coasts are 

 S. maculatus. 



There is disagreement in the literature on the 

 interpretation of annuli on otoliths of Spanish 

 mackerel. The first information on age and 

 growth of S. maculatus was from fish collected in 

 southeast Florida (Klima 1959). Later, Mendoza 

 (1968) gave some limited age and growth infor- 

 mation on S. maculatus from Veracruz, Mexico, 

 and Powell (1975) provided the most recent infor- 

 mation on Spanish mackerel age, growth, and 



^Southeast Fisheries Center Panama City Laboratory, Na- 

 tional Marine Fisheries Service, NOAA, 3500 Delwood Beach 

 Road, Panama City, FL 32407-7499. 



reproduction in Florida. Powell interpreted an- 

 nuli on Spanish mackerel otoliths differently 

 than did Klima, and the different age determina- 

 tions yielded different growth estimates. Men- 

 doza (1968) did not estimate growth except by 

 presenting his data in tabular form. 



We undertook this investigation to resolve 

 these uncertainties in the literature and to derive 

 more current age and growth parameters. This 

 information will provide a better basis for ra- 

 tional management of this species. 



STUDY AREA AND METHODS 



We collected 1,929 Spanish mackerel from 1977 

 through 1981 from the south Atlantic and Gulf of 

 Mexico coasts of the United States. Most (1,422) 

 of the fish came from northwest Florida and only 

 10 came from north of south Florida on the At- 

 lantic coast (Table 1). Fork length (FL) of each 



Table 1. — Numbers of Spanish mackerel collected for age and 

 growth study. 



Manuscript accepted July 1987. 



FISHERY BULLETIN: VOL 85, NO. 4, 1987. 



777 



