|
|
Využívání dlouhodobého uvolňování léčiv v reprodukci ryb
KNOWLES, Jindřiška
The PhD thesis was aimed to develop and validate an innovative method of hormone stimulation using PLGA microparticles for sustained release of a synthetic analogue of mammalian gonadotropin-releasing hormone in several economically important fish species. Since this is the first record of the use of PLGA microparticles in fish, the focus was to establish the optimal dose of the active substance, quantify the steroid response of the broodstock, and to assess the quality and quantity of obtained sex products. The theoretical part of the thesis was focused on elaborating a study reviewing methods of hormonal treatment in fish, and discuss the potential of PLGA microparticles in fish reproduction. While, the experimental part of the work was focused on evaluation of the effect of PLGA microparticles in those fish species commonly reared in intensive and pond aquaculture. Fish of both sexes were included to determine the effect of the treatment on the production and quality of eggs as well as on the quality and quantity of sperm.
|
|
|
Hormonal induction of ovulation in whitebarred catfish (Agamyxis pectinifrons)
KNOWLES, Jindřiška
The aims of presented work are reviewing of current knowledge about biology and artifical reproduction, evaluation of dopamine inhibition of LH secretion and identification of optimal hormonal treatment of ovulation in tropical whitebarred catfish. Two trials were conducted in years 2012 and 2013. The experiments differed from each other only in the water temperature 29,5 °C (Experiment No.1) and 26 °C (Experiment No.2). In each experiment, the fish were divided into 4 groups. Group A was injected only with mGnRHa, group B was injected with dopamine inhibitor metoclopramide, group C was injected with mGnRHa plus metoclopramide and group D was injected only with physiological saline (0,9 % NaCl). Ovulation occurred only in the groups injected with the combination of GnRHa and dopamine inhibitor, however in both experiments. In Experiment No.1, the ovulation rate was around 60%, relative fecundity was 331,025 +- 47,508 eggs . kg-1, latency interval was at 10.3 +- 0.6 hours and the fecundity index was determined at 13, 8. In Experiment No. 2 ovulation, the level of ovulation was 50%, relative fecundity was 408,561 +- 34,934 pieces of eggs . kg-1, latency interval was 13.7 +- 0.7 hours and fecundity index was 15.35. The results clearly show a strong inhibition of dopamine on LH secretion and show that the combination of GnRHa with dopamine inhibitor can be successfully used to induce ovulation in whitebarred catfish.
|
guest ::
