Age and growth of white grunt (Haemulon plumieri):: A comparison of two populations along the west coast of Florida

Sex-specific age and growth were determined for white grunt, Haemulon plumieri (Lacepede, 1801), from their main fishing area on the Gulf coast of Florida. In total, 4043 fish were collected using hook-and-line or trap gear: 2617 from the central and 1426 from the north-central Gulf coast of Florida. White grunt were aged reliably using thin-sections of sagittal otoliths. Both marginal-increment analysis and chemical marking with oxytetracycline indicated that one annulus was deposited in a 12-mo period, with the opaque zone forming mainly during May. Ages of white grunt ranged from 0-18 yrs, and fish ranged in size from 7-41 cm total length. White grunt from the north-central region were larger at age than those from the central region, and males attained a larger size than females in both regions. Asymptotic lengths of males and females combined ranged from 296-343 mm total length. Comparatively, white grunt from the Gulf coast of Florida were of similar size-at-age as fish from southeastern (Atlantic) Florida but were smaller than white grunt from North and South Carolina. Regional growth differences of white grunt are problematic for any comprehensive fishery management plan on a Florida-wide, Gulf-wide, or southeastern U.S-wide basis.