UTILIZATION OF SUBTROPICAL SEAGRASS MEADOWS BY NEWLY SETTLED RED DRUMSCIAENOPS-OCELLATUS - PATTERNS OF DISTRIBUTION AND GROWTH

Spatial and temporal variability in distribution and growth of newly s ettled red drum Sciaenops ocellatus were examined in the Aransas Estua ry, Texas, USA. Overall, 1891 red drum larvae and early juveniles (4 t o 30 mm standard length, SL) were identified from weekly epibenthic sl ed collections taken during the annual recruitment period (September-D ecember 1994). Densities ranged from 0.0 to 3.4 ind, m(-2), with peak values observed in mid to late October. Density varied significantly b etween habitats (Halodule wrightii vs Thalassia testudinum) and among sites. Otolith-based techniques were used to determine hatch-date dist ributions and individual growth rates of newly settled red drum. Hatch dates of individually aged red drum (n = 324) ranged from September 4 to October 30 (57 d). Hatch dates were used to separate individuals i nto 10-d cohorts and cohort-specific growth rates were estimated from exponential size-at-age plots. Cohort-specific instantaneous growth co efficients (g) ranged from 0.041 to 0.058 d(-1) with highest values oc curring for mid-season cohorts. Spatial and temporal patterns of recen t growth (mean increment width over 5 d) were also investigated. Recen t growth rates were highest for mid-season cohorts and relatively unif orm between habitats and among sites. Since spatial trends in density were not explained by growth differences, we hypothesize that factors other than growth potential were influencing the distribution of newly settled red drum in the Aransas Estuary.