Distribution, Growth and Mortality of Larval Spotted Seatrout, Cynoscion Nebulosus: A Comparison Between Two Adjacent Estuarine Areas of Southwest Florida

Distribution, growth, and mortality of larval spotted seatrout, Cynoscion nebulosus, were compared between the Naples Bay and Fakahatchee Bay areas of southwest em Florida during the period of July 1983 through January 1985. Back-calculated spawning dates ranged from mid-March through mid-October, with major peaks occurring during the warmer months. Monthly larval densities were positively correlated with water temperature in Naples Bay (r = 0.35, P < 0.01). Cumulative larval lengths were significantly smaller (P < 0.001) in Naples Bay, suggesting a greater proximity of collection stations to spawning locations in this area. Station-specific length distributions indicated that spawning probably occurred in the lower part of Naples Bay and in shallow Gulf of Mexico waters near the Fakahatchee study area. Salinity and temperature are discussed as determinants of spawning activity and larval distribution. A growth rate of approximately 0.4 mm/d was found for both areas. The apparent instantaneous daily mortality coefficient was significantly larger for Naples Bay (0.64 vs. 0.36, P < 0.001).