The use of trifluralin to control fungal infection and to increase hatching rate of fertilized eggs of brood ship sturgeon (Acipenser nudiventris) in Guilan Province

Abstract

The purpose of this study was to use the Treflan (a herbicide) to reduce fungi and increase the hatching rate of eggs of ship sturgeon, in Youchtchenko incubator. A brood ship sturgeon with the weight of 10 kg, produced 3.6 kg eggs. After fertilization process, 300 g eggs (approximately 8800±120 eggs) were distributed into each box of Youchtchenko incubator (each incubator has 4 boxes). The research was carried out with 4 treatments and 3 replication in each treatment. The research was conducted at the International Sturgeon Research Institute and Beheshti Sturgeon Restoration and Genetic Conservation Center, in 2017. Treatments included control (no added Treflan) and 3 different concentrations of Treflan, treatment 1 (0.1 mg/L), treatment 2 (0.05 mg/L), treatment 3 (0.025 mg/L). 24 hours after placing the fertilized eggs in the incubator, the addition of Treflan was done, and up to 48 hours was used once and then used twice daily until the end of the incubation time, as a 15 min bath. Fungal eggs were syphoned and weighed daily. By determining the no of fungal eggs per g of samle, the no of fungal eggs was determined. 48 hours after incubation, the number of fungal eggs reached the highest levels in treatments. But, in control treatment (due to lack of adding Treflan) was significantly more than other treatments) P<0.05(. In treatments 2 and 3 the remained eggs and the hatching rate, were significantly lower than other treatments) P<0.05(. Possibly, the use of Treflan in two concentrations of 0.025 and 0.05 mg/L has negative effects, may be due to low concentrations and use as a temporary bath. After 96 hours, the eggs were completely hatched. Hatching rate in treatment 1 (2836±132.93), was significantly more than control and treatments of 2 and 3 (1657±145.66, 1470±84.82 and 1429±79.19 respectively) (p<0.05). The results indicated that Treflan can be successfully used in the proper and non-defective function of Youchtchenko incubator, at a concentration of 0.1 mg/L.