|
|
Preventivní a léčebné koupele u plůdku candáta obecného (Sander lucioperca)
PITHARDT, Tomáš
The aim of this thesis was to test and compare the effect of four selected and in present commonly used medical treatments on other species of fish in recirculating aquaculture system (RAS). This presented work was divided into two separate experiments dealing with curative baths for fry of pikeperch.The fry was raised in ponds, feeded by natural food, with the intention of adaptating for RAS after a bath. Baths were targeted against parasitic and bacterial diseases by using Bellasav, SAVO Original, formaldehyde and Chloramine T. The curative baths took 30 minutes after which the fish were transferred to clean water where the mortality within 24 hours and the efficacy of the preparation within 24 hours was monitored. In the first experiment were used fish with an average weight of 0.23+-0.05 g and a total lenght of 31.7+-2.5 mm at the age of 35 days. The tested doses were 0.5; 1; 1.5; 2; 5; 10 and 50 ml.m-3 for Bellasav, 1; 5; 10; 20 and 50 ml.m-3 for SAVO Original, 0.5; 1; 1.5; 2.5; 5; 10; 15; 30; 45 and 50 ml.100 l-1 for formaldehyde and 10; 20; 30; 40; 50; 100; 150 and 200 mg.l-1 for Chloramine T. The best efficacy was achieved at the concentration dose 1.5 ml.m-3 for Bellasav. The concentration dose 10 ml.m-3 of SAVO Original only reduced parasitic infection by one degree. An effective dose of formaldehyde was 1 ml.100 l-1 which reduced the parasitic infection by two degrees. The most effective preparation was Chloramine T at the concentration dose of 30 mg.l-1. In the second experiment were used fish with an average weight of 1.6+-0.4 g and a total lenght of 60.4+-3.56 mm at the age of 70 days. The tested doses were 10; 20 and 50 ml.m-3 for Bellasav, 10; 20 and 50 ml.m-3 for SAVO Original, 2.5; 5 and 10 ml.100 l-1 for formaldehyde and 40; 150 and 200 mg.l-1 for Chloramine T. The best efficacy was achieved at the concentration dose 20 ml.m-3 for Bellasav and 10 ml.m-3 for SAVO Original. The most effective dose for formaldehyde was 2.5 ml.100 l-1 which reduced the bacterial infection in fish skin by two degrees. The most effective preparation was Chloramine T again at the concentration dose 40 mg.l-1.
|
|
|
The optimization of transfer Northern whitefish larvae (Coregonus peled) on complete feed mixture.
PITHARDT, Tomáš
In this work was tested optimal rearing protocol for Northern whitefish larvae in two experiments. Both experiments lasted for 34 days. In the first experiment the effect of feed particle size on the survival and growth were tested in Northern whitefish larvae with initial body weight of 3.01 +- 0.48 mg. Larvae were weaned from live feed 10th, 15th, 20th, 25th and 30th day after hatching when co-feeding was took for 3 days before the weaning. In the first experiment were tested particle size of 100 micrometers and 300 micrometers. Groups weaned 20th, 25th and 30th with 100 micrometers feed and groups weaned 25th and 30th with 300 micrometers feed had similar final survival (without significant differences). The best growth (final weight 39 +- 12 mg) had group weaned 30th day after hatching using particle size of 300 micrometers. In the second experiment the effect of length of combined feeding (co-feeding) on the survival and growth were tested in Northern whitefish larvae on a unit weight 3.01 +- 0.48 mg. Co-feeding lasted for 1, 3 or 6 days before the weaning. Larvae were weaned from live feed 10th, 15th, 20th, 25th and 30th days after hatching. Groups weaned 10th, 15th, 20th, 25th and 30th had similar final survival (without significant differences). But the best growth (final weight 37 +- 15 mg) reached group weaned 30th day after hatching with combined feeding for one day. Groups weaned 20th, 25th and 30th had similar final body weight (without significant differences). There was no observed effect of co-feeding duration on survival and growth.
|
guest ::
