GROWTH AND MORTALITY OF LITTLE TUNNY (EUTHYNNUS-ALLETTERATUS) LARVAE OFF THE MISSISSIPPI RIVER PLUME AND PANAMA-CITY, FLORIDA

Larval and early juvenile little tunny, Euthynnus alletteratus, were c ollected from the northern Gulf of Mexico (434 fish from the Mississip pi River delta region and 150 off Panama City, Florida) using a I x 2 m, 0.947-mm mesh neuston net and a 1 x 1 m, 0.333-mm mesh Tucker trawl . Sagittae were removed from 200 fish collected from the Mississippi R iver delta region and 150 collected from off Panama City, Florida, and examined whole at 800X magnification. Daily growth increments were vi sible in the sagittae of little tunny (2.5-14.0 mm SL) which ranged in age from 2 to 13 d. Growth estimated as the slope of a regression of SL on age, was rapid (1.07 mm d(-1)). Fish collected off Panama City g rew faster than those collected in the vicinity of the Mississippi Riv er discharge plume. Instantaneous daily mortality rates, estimated fro m survivorship curves were higher in the Mississippi River plume fish (0.95) than those from Panama City, Florida (0.72).