AGE AND GROWTH OF LARVAL AND JUVENILE ATLANTIC CROAKER, MICROPOGONIAS-UNDULATUS, FROM THE MIDDLE ATLANTIC BIGHT AND ESTUARINE WATERS OF VIRGINIA

Sagittal otoliths were used to determine age and growth of 605 larval and juvenile Atlantic croaker, Micropogonias undulatus, collected in t he Middle Atlantic Eight and estuarine waters of Virginia. This study is the first to use age-based analysis for young Atlantic croaker coll ected in this region. A Laird-Gompertz model (r(2)=0.95) was used to d escribe the growth of Atlantic croaker up to 65 mm standard length (SL ) and 142 days (t): SL(t) = 2.657 exp (4.656 [1-exp (-0.0081t)]); wher e SL(t) = standard length at day t. Spatial and temporal patterns in t he size and age of Atlantic croaker showed a pattern ofinshore immigra tion from offshore spawning grounds, and faster early-season growth co mpared with late-season growth. Back-calculated hatching dates of Atla ntic croaker collected in Virginia estuaries indicated a protracted sp awning period over 8 months, from early July 1987 to early February 19 88, with at least 82% of spawning occurring from August to October. Re gression analysis indicated that early-spawned larvae (July through Au gust) grew more than 39% faster than late-spawned larvae (September th rough February). Lapillar and sagittal otoliths were compared with lig ht microscopy; ages were underestimated with lapillar otoliths, which were particularly inadequate in determining the age of older juveniles . The relation between SL and sagittal otolith maximum diameter was be st described by a fourth order polynomial(r(2)=0.99) and faster-growin g Atlantic croaker had larger otoliths (12%) than the same size slower -growing fish.