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Effects of hormonal treatment during artificial reproduction to produce to fingerlings of weatherfish (Misgurnus fossilis)
HOUDA, Ondřej
In this M. Sc. thesis, the influence of selected commercially available hormonal preparations based on hCG (Pregnyl, Chorulon) and GnRH-a with dopamin inhibitor (Ovopel, Dagin, Ovaprim) and their benefits were studied, compared with homogenate of carp pituitary (CPE), during controlled reproduction of weatherfish (Misgurnus fossilis, Linnaeus, 1758) in artificial conditions on the quality of the produced fry. The goal of this thesis was assess the suitability of individual commercially produced hormonal preparations for controlled reproduction of weatherfish and the possibility to replace with them unstandardized use of homogenate of carp pituitary. It was found that use of various hormonal preparations and dosage may to in some extent affect hatchability and survival rate of larvae (fry), the size of the yolk sac of larvae, and the amount of energy deposited in body tissues of larvae. However, demonstrable difference in studied parameters for the application of different preparations on the different hormonal basis (hCG versus GnRH) was not reported. The highest rate of hatching larvae (93.3 ? 3.8%) was observed in the groups treated with preparation Pregnyl 3000 IU - kg-1. In terms of overall survival of the larvae (from deployment of hatched eggs until the end of the experiment) have proven to be the most effective medication Pregnyl 3000 IU - kg-1 (69.9 ? 12.1 %) and Dagin (60.56 ? 11.71 %). Within the thesis has been demonstrated no relationship between hormonal treatment used and the growth of larvae (in terms of achieved total length of body and dry weight). The amount of energy deposited into the body tissues of larvae (gross calorific value) was comparable in all groups, except Dagin preparation, which was recorded impairment losses. For the best, most effective and commendable for control of reproductive hormone preparation carp pituitary homogenate replacing the terms of the assessed indicators can be seen the preparation based on hCG and that is Pregnyl at a dose of 3000 IU - kg-1.
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The present distribution of species of the family Cobitidae over the Slovakian drainage area of the Tisza River
Koščo, J. ; Košuth, P. ; Lusková, Věra ; Lusk, Stanislav ; Košuthová, L. ; Halačka, Karel
Cobitis elongatoides is common to frequent in the eastern Slovakian part of the Tisza drainage area (d.a.) where it populates all habitat types. The occurrence of this species is less frequent in the western part of the Tisza d.a. No marked differences have been observed in the past and present distribution of this species. The occurrence of Misgurnus fossilis is concentrated in the lowland areas of the Tisza d.a., particularly in its eastern part. Ichthyocoenoses in which M. fossilis occurs are poorer in species, and they overlap considerably with those containing C. elongatoides but differ markedly from those containing Sabanejewia balcanica. M. fossilis was rather successful in adapting to artificial wetlands. The species is rather rare in western part of the Tisza d.a. The range of S. balcanica is shifted more upwards to the submontane region, exclusively in running waters. No marked differences have been observed in the past and present distribution of this species.
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