AIR INCUBATION OF EGGS OF THE GULF KILLIFISH

Effects of air incubation on egg hatchability and subsequent fry growt h of gulf killifish (Fundulus grandis) were examined in the laboratory . Mats with approximately equal coverage of pond-spawned eggs were kep t moist at a temperature of 22-degrees-C. First hatch of eggs transfer red from mats to water occurred at 19 d postspawning. Total hatching o ccurred in 24 h, with 90% hatching in 2 h. After 31 d of air incubatio n, deaths of hatched fry were first noted. Air incubation on mats was terminated at 36 d. Laboratory-spawned eggs were incubated on moistene d filter paper in a sealed container at 26-degrees-C. Air incubation p eriods were 0, 6, 12, 18, and 24 d. For eggs with 0 d and 6 d air incu bation, hatching occurred 8-11 d after they were spawned. Eggs incubat ed in air for 12 d and longer hatched after 30 min in water. Mean surv ivals were significantly higher in the 6- and 12-d groups (95 and 92%) than in the 0- and 18-d groups (85 and 83%). All of these survival va lues were significantly higher than in the 24-d group (66%). Growing o f fry to harvestable adults resulted in survival trends similar to tho se found in hatch results; the best survival (97%) was for the 6-d inc ubation group and lowest survival (72%) was for the 24-d group. No sig nificant differences in growth or lateral line scale counts were noted among the time intervals, but significant differences were found in t he number of vertebrae and in numbers of dorsal, anal, and pectoral fi n rays.