National Repository of Grey Literature 4 records found  Search took 0.01 seconds. 
Management generačních ryb candáta obecného (Sander lucioperca) a jeho vliv na produkci jiker a larev
MALINOVSKYI, Oleksandr
This thesis provides an improve to existing reproduction technics through investigation of ecology and physiology features of pikeperch broodstock: (I) Spawning behavior and selectivity to different types of spawning substrates as an important part of the biology of pikeperch species. The main output of the study was revealing of strong selectivity to the spawning site with neither water temperature nor availability of spawning places haven't affected substrate preference of pikeperch broodstock. (II) Spawning in captivity is leads to decrease in physiological status of the pikeperch broodstock, especially in females. It was found that one of the reasons of the decrease was male protective behavior, that in limited space of the reproduction unit is forwarded to female. Separation of the sexes significantly reduces number injuries and improved physiological status of the broodstock. (Ill) The study investigated efficiency of different antifungal agents for pikeperch broodstock. The long term exposure to salt bath in concentration of 2.5, 5 and 10 g L-1 and formaldehyde in concentration 0.015 ml L-1 were found to be highly effective and significantly decreased mortality after spawning. In addition, treatment with salt bath are environmentally friendly and recommended for practical use as an effective way to prevent mortality of pond-cultured pikeperch broodstock. (lV) The provision of live feed is crucially important for proper gametes maturation, particularly in pond-cultured fishes not accepting pellets. The study investigated the effect of temperature on daily biomass of prey consumed by pikeperch broodstock. Significantly increased prey consumption was found after temperature reached 4.5 °C. Females exhibited significantly higher prey consumption rate in compare to male. Study revealed the tendency for pikeperch to consume largest available prey after water temperature reached 8.5 °C.
Odběr spermatu pomocí katetru a jeho využití při výtěru štiky obecné (Esox lucius L.)
PLAŇANSKÝ, Tomáš
The aim of this diploma thesis is to compare quality of northern pike sperm collected by different methods. First method is collection of stripped sperm by abdominal massage of the belly. Second method is collection of stripped sperm with special catheter to eliminate sperm contamination by urine. The last method is collection of testicular sperm. Differently collected sperm was evaluated and compared its quality. The main observed parameters were sperm volume, spermatozoa concentration, spermatozoa motility and velocity and osmolality of seminal fluid. Sperm samples were used for eggs fertilization. In fertilized eggs, the fertility of eggs and larvae hatching rate were observed.

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