Mycteroperca Microlepis Research Articles

Age and Growth of the Gag, Mycteroperca microlepis, and Size-Age Composition of the Recreational Catch off the Southeastern United States

Abstract Otoliths of the gag grouper, Mycteroperca microlepis, sampled from the headboat fishery off the southeastern United States were examined to determine age. The oldest fish collected was age XIII and 1,201 mm total length. Back-calculated mean lengths of 136 fish ranged from 269 mm at end of year 1 to 1,080 mm at end of year 13. The von Bertalanffy equation describing theoretical growth in length is Lt = 1,290 (1 - e-0.12154(t+1.127)), where L = total length (mm) and t = years. The length-weight relationship is described by the equation W = 1.2 × 10-8L2.996, where W = weight in kg and L = total length in mm. Only slight differences were noted in length-weight relationships between geographical locations. The average fish landed by the recreational fishery was 825 mm total length and 6.56 kg. Approximately 34% of the gag landed were age × and older. Apparently the rate of natural mortality increases drastically after age XII.

Appearance of the Gag, Mycteroperca microlepis, in Coastal Waters of Virginia

Eighteen young gag,Mycteroperca microlepis, 61–186 mm F.L., were recorded from Chincoteague Bay, Eastern Shore waters, off Virginia Beach, and within Chesapeake Bay from July to November 1960. Average lengths at progressive collecting periods suggest rapid growth. Coloration and pattern varied somewhat among the specimens.