Testování háďátka octového (Turbatrix aceti) a substrátů pro eliminaci olejových látek z povrchové blanky pro raná stádia okouna říčního (Perca fluviatilis)

This thesis evaluates an alternative life food Turbatrix aceti for feeding of European perch in its early life stages and the possibility of oily substances elimination from the surface water layer in perch aquaculture. It is of crucial importance to provide perch live food up to 20 days after hatching. Artemia sp. is commonly used for perch feeding in its early life stages. Five different feeding treatments with six replicates in each treatment were performed. The main investigated parameters were fish survival and growth (weight). Average survival (expressed as the number of fish survived) in each of five feeding treatments were: T 107, A5T1 5 145, A10T10 150, A 196 and A15T5 207. Treatment A and A15T5 were not significantly different. After termination of the experiment, the average weights in mg ? standard deviations after 20 days of rearing in given treatment were: A - 28.0 ? 7.7; T 2.9 ? 1.4; A5T15 4.4 ? 3.3; A10T10 7.4 ? 1.1 and A15T5 - 15.9 ? 2.7. The results indicate that Turbatrix aceti cannot be used for rearing of perch early life stages, since mortality was higher and weight lower than in control group, where Artemia sp. was used as a live food. The second experiment tested the possibility to reduce amount of swim bladder inflation failures in perch intensive aquaculture using several types of surface substrates. Swim bladder inflation rates in each treatment were as follows: O 55%, S 40 %, MT 58 %, ML 38 %, PP 65 %, C 48 %. The treatments were not significantly different from each other. Used surface layer collectors of oily substances have not been proved successful, since the percentage of successfully inflated swim bladders were not different from the control treatment, where no surface layer collector of oily substances was used