Studies in egg handling and incubation in the spotted rose snapper Lutjanus guttatus (Pisces Lutjanidae)

Abstract

Egg handling and incubation are short but important procedures in juvenile fish production technologies. To determine appropriate practices for egg handling and incubation in the spotted rose snapper Lutjanus guttatus (Steindachner, 1969), three experiments were carried out in 100-L fiberglass conical cylinder tanks. Eggs were incubated with and without water flow (30% volume/h), at two densities (250 eggs/L and 1000 eggs/L), and with and without formaldehyde 10-ppm prophylactic treatment for 1-h prior to incubation. Total hatching and larvae survival percentages were not significantly different between the treatments with and without water flow, while results for larvae survival at hatching time and 48 h post-hatch stage were significantly better without water flow. For incubation at two different densities, all examined performance indexes were significantly better at the lower density, except for larvae survival at 48 h after hatching. The eggs with and without prophylactic treatment were not significantly different in all analyzed survival indexes at hatching time and 48 h post-hatch. Total length was significantly different in all treatments at hatching time and 48 h post-hatch, except in the incubation without water flow. The longest larvae were obtained in the experiment with prophylactic treatment.