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Vliv teploty při krátkodobém uchování jiker jesetera malého, Acipenser ruthenus, in vitro
LET, Marek
The effects of temperature (7°C, 11°C, 15°C, and 19°C) and egg storage time (Control = time 0 h, 2.5 h, 5.0 h, 7.5 h and 10.0 h) on the fertilization and hatching success of sterlet, Acipenser ruthenus, eggs were studied. Ovulation and spermiation were stimulated by using CPE in two dosages for females (first dose 0.5 mg.kg-1 b.w. and second dose 4.0 mg.kg-1 b.w.) and one dosage for males (4.0 mg.kg-1 b.w.), respectivelly. The ovulated eggs were collected from three females (age 68 years) through a small surgery, than mixed together. The good quality semen was selected from three males (age 68 years) and was stored in polystyrene ice box during the experiment. The eggs were placed separately into four incubators, where were stored in above-mentioned temperature conditions. Four grams of eggs from each temperature treatment groups were inseminated with 200 ?l of the semen in dechlorinated water at 15°C. Then, eggs were placed into experimental cage incubation system with separate chambers at 15°C and a small sample of fertilized eggs was allocated in triplicate to plastic petri dishes for evaluation of fertilization rate during neuralization phase. Approximately, 56 days post-fertilization, the total number of succesfully hatched larvae was acurately calculated for the final evaluation of storage success. All data were analyzed using STATISTICA v 12 software. Hatching success was analyzed using a factorial ANOVA model containing the egg storage time and storage temperatures. Eggs retained their hatchability when stored at 7°C and 11°C for up to 10 hours. Egg viability was noticeably reduced at 7.5-h storage at 19°C compared to cooler temperatures, moreover the viability decreased significantly after 10 hours at 19°C. In contrast with the one previous study about shor-term storage of sterlet eggs, this experiment probably dealt with better quality eggs which can be a reason why they retained their hatchability for significantly longer time period.
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