Embryonic survival of Galaxias maculatus (Jenyns, 1842), under different prophylactic immersion bath

Abstract

The use of antifungals was assessed to improve embryo survival of Galaxias maculatus. Three treatments using formalin dose of 250 ppm, iodine dose of 100 ppm, and sea salt in doses of 30 ups were designed, and a control treatment under 10 of salinity water. For each treatment and control, 15 replicates were used, with 100 embryos in each replicate. Embryos were immersed into each treatment solution for one hour every two days. Larval survival after 15 days old was assessed. Higher embryonic and larval survival was obtained in sea salt treatment improving by 27.4 and 11.6% (P < 0.05) respectively over control results. Formalin treatment resulted in embryonic and larval survival of 9.8 and 4.0% respectively more than control (P < 0.05) and in the case of iodine embryonic survival, 2.6% more than control (P > 0.05) and larval survival of 16.4% lower than the control (P < 0.05). In conclusion, sea salt shows greater effectiveness as a prophylactic treatment to improve the embryonic survival of G. maculatus.