micron mesh neuston net. Eggs were also obtained from a striped bass hatchery 

 run by the state of South Carohna at Moncks Corner, South Carohna. Eggs 

 were air-shipped to the University of Rliode Island, where all experiments 

 reported here were performed. 



Experimental Procedures 



For the duration of the relatively short incubation period, eggs were 

 maintained in static 208 liter polyethylene drums filled with dechlorinated tap 

 water. Best hatching success was observed when bacteria were controlled using 

 an antibiotic. The antibiotic dosage used was 50,000 I.U. /liter penicillin G plus 

 50 mg/Hter streptomycin sulfate. A strong air stream maintained the eggs in 

 suspension and maintained an adequate dissolved oxygen level. Dead eggs 

 floated to the surface and were removed as they were discovered. One-half of 

 the volume of the tanks was replaced daily. Water temperature was maintained 

 at laboratory room temperature, 14-16°C, during incubation. 



The experimental containers used in growth experiments consisted of four 

 liter glass beakers. Prolarvae were stocked into these containers usually within 

 24 hours of the time they were hatched. Larvae stocked at yolk absorption 

 were held in their incubation containers until visible vestiges of yolk had 

 disappeared. At stocking, all were of the same chronological age and had been 

 exposed to the same conditions prior to the beginning of the experiment. No 

 antibiotic was used in larval growth or survival experiments. The water used in 

 all experiments was raised to 5^/oo salinity by mixing dechlorinated tap water 

 with seawater (32°/oo, which had been passed through a cartridge filter rated 

 to retain particles larger than 5 microns). Water in each container was changed 

 every two days. 



Constant temperatures of 15, 18, 21, 24, and in some cases 27°C, were 

 maintained in the test containers by keeping them immersed in temperature 

 controlled water baths. Bath temperatures were controlled using Haake (model 

 E-52) 1000 watt heater-thermoregulators operating against a cooling coil in 

 each bath. Temperature excursions of no more than 0.25*^C were normally 

 encountered. The temperatures used span the range that might be encountered 

 by developing larvae in nature. Bath temperatures were monitored on a 

 strip-chart recorder and measured manually at least twice a day during the 

 course of experiments. 



In initial experiments, dissolved oxygen, pH, ammonia, and sahnity 

 measurements were made regularly. Dissolved oxygen was determined using the 

 Y.S.I. D.O. probe, supplemented periodically with determinations using the 

 azide-modification of the Winkler titration. The pH was measured using an 

 Orion pH electrode. Ammonia was determined using a micro-modification of 



238 



