Alternate Title

Age and Growth of the Warsaw Grouper and Black Grouper from the Southeast Region of the United States


Opaque rings on sectioned otoliths from warsaw grouper, Epinephelus nigritus (N = 124), and black grouper, Mycteroperca bonaci (N = 172), were used to estimate age and growth. The aging structures from warsaw grouper were obtained by dockside sampling of headboat landings from North Carolina through the Florida Keys. Black grouper were sampled from headboat landings primarily in the Florida Keys. Annulus formation occurred between April and May for warsaw grouper, and from March through May for black grouper. The weight-length relationship for warsaw grouper is W = 2.09 x 10-5L2.9797, and for black grouper is W = 5.548 x 10-6L3.141, where W = weight in grams and L = total length in millimeters. Mean back-calculated total lengths for warsaw grouper ranged from 292 mm at age 1 to 2,328 at age 41, and from 260 mm at age 1 to 1,110 mm at age 14 for black grouper. The von Bertanlanffy growth equation for warsaw grouper is Lt = 2,394 (1·e-0.0544(1 + 3.616)), and for black grouper is Lt = 1,352 (1·e-0.1156(1 + 0.927)), where t = age in years and L = total length in millimeters. Both species have growth characteristics that are similar to most other serranids studied along the southeastern United States. Catch curves and a yield-per-recruit model are presented for black grouper.