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Changes of IgM expression levels in the head kidney of Cyprinus carpio following an infection with Sphareospora molnari
SIERANSKI, Viktor
Sphaerospora molnar is a myxozoan inducing sphaerosporosis in common carp and causing serious damage to secondary lamellae and epithelia of the gills. The understanding of the host immune response against S. molnari as well as other myxozoans is very limited in part due to the unresolved life cycle. The focus of this thesis was the quantification of membrane bound and secretory IgM expression levels in the head kidney over a period of 9 weeks following an intraperitoneal injection of S. molnari blood stages. Significant increases in the expression levels of both IgMs were observed reaching its maximum at 42 days after infection. Two weeks following the infection the first significant increases of secretory IgM were detected.
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Interakce spermií a jiker u sladkovodních ryb: vliv prostředí na fertilizační proces
KHOLODNYY, Vitaliy
Fertilization of fresh water fish occurs in an environment which may affect negatively the gametes, therefore the fish male gametes should reach their counterpart, the female gamete, as soon as possible because spermatozoa become damaged within minutes or less due to osmotic shock. Existence of specific mechanism triggering, supporting and guiding the encounter of gametes would be highly expedient in these conditions. The eggs of many externally fertilizing freshwater fish species are released into the external milieu surrounded by a coat of ovarian fluid (OF) with a composition ideal for supporting and protecting eggs and sperm against the deleterious effect of freshwater. The existing data support the idea that the properties of OF and/or the specific compounds contained in it or released by the eggs could significantly affect the behavior of male gametes and consequently influence the outcome of fertilization in terms of the number of fertilized oocytes. The mechanisms which facilitate and trigger gametes' encounter are also highly demanded in terms of natural selection. It was found that presence of OF affected significantly the behavior of rainbow trout spermatozoa, in particular, their motility traits: higher velocity was supported for longer time and trajectories were straightened, comparing to those observed in water. In the microcapillary spermatozoon accumulation test (test of chemotactic response) the rainbow trout OF showed a trapping effect on activated male gametes which depended on osmotic properties of the activating media. Different molecular weight fractions from OF affected the tactic behavior of the cells in a various way. The most significant trapping effect was rendered by low molecular fraction and the possible chemotactic agent was found to be thermostable. The trapped cells showed specific turn-and-run behavior accompanied by asymmetric bending of flagella and burst-like increase of calcium concentration in the bended area. The in vitro fertilization test revealed the enhancement of spermatozoa performance, especially in the samples from the related individuals, which led to the higher embryo development rate. Presence of particular concentration of ovarian fluid (30% solution in water) had inhibiting effect on sterlet spermatozoa motility initiation. Lower concentrations of the ovarian fluid improved the longevity of spermatozoa and did not affect their trajectories. Test of chemotactic response showed no effect of ovarian fluid on spermatozoa behavior, while at the same time the attracting effect of egg conditioned medium was evident (i.e. due to some substances released from the eggs during their contact with fresh water). The results of in vitro fertilization test showed that presence of ovarian fluid prevented the eggs from losing the fertilizing ability due to the contact with water, as well as promoted the spermatozoa to fertilize the eggs during longer period of time. Presence of common carp ovarian fluid in the activation medium caused the decrease of the velocity of spermatozoa comparing to the OF-free medium and significantly altered the motility pattern from straightforward motility observed in the water to the tumbling in the medium with high OF content (50%). Introduction of OF (in the sperm accumulation test) entailed immediate and prominent chemotactic-like reaction of spermatozoa. The environmental conditions which accompany the encounter of gametes, in particular presence of OF, calcium ion content and osmolarity, significantly affect the performance of male gametes in spermatozoa in rainbow trout, sterlet and common carp in terms of changes in velocity, path linearity and ability to response to the external signals, e.g. attractants. The conducted study allowed to conclude that way how the ovarian fluid affects the behavior of spermatozoa in these species may be associated with their reproduction (spawning) strategy.
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Vliv produktů ze zpracování konopí ve výživě kapra obecného (Cyprinus carpio L.)
Palíšek, Ondřej
The aim of this study was to compare the effect of feed mixtures with different proportion of cannabis products on fingerling of common carp (Cyprinus carpio L.). The addition of hemp cake to feed was tested. The feed experiment was conducted in period 21.9.2016 - 21.11.2016 in recirculation system consisting of 10 tanks of 200 l volume connected to a biofilter. During the experiment, control weight measuring was performed and the hydrochemical and physical parameters in every tank were recorded. Fish were fed feedstuff with 5 %, 10 % and 15 % of hemp cake. On average, the fish grew from 35.37 grams to 57.24 grams. The best feed conversion ratio (FCR), specific growth rate (SGR) and ratio of these two values achieved fish fed feeding mixture number 2 with 10 % of cannabis cake (FCR 3,14, SGR 0,83 %, FCR/SGR 3,96). Statistical significant influence of feed mixture on content of proteins, fats and n-3 fatty acids in carp muscle was not proven.
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Využití produktů ze zpracování konopí ve výživě ryb
Žejdl, Matěj
The aim of this bachelor‘s thesis was to create a literary review on the utilization of cannabis products in fish diets, mainly of common carp (Cyprinus carpio L.) and Nile tilapia (Oreochromis niloticus L.). Other plant-based feeds and their possible use in fish nutrition and nutrition of different farm animals were also studied. Furthermore, the issue of fish digestion and their nutrient requirements in feed was outlined. Part of the work contains a method for the conduction of a feed test, which will be performed on fish species Cyprinus carpio and Oreochromis niloticus in a recirculating aquaculture system at the Department of Fisheries and Hydrobiology at the Mendel University in Brno. Fish will be fed granulated mixtures, with the addition of products from processed cannabis. Lenght-weight parameters, production parameters and the effect of feed on fish organism and chemical composition of their tissues will be determined.
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Physiochemical Parameters of Ponds during Hydrological Year
HUMMELOVÁ, Světlana
Physiochemical Parameters of Ponds during Hydrological Year The aim of this Bachelor thesis was to use the obtained data for the assessment of these physiochemical parameters on growth of the carp. The obtained data and their influence on carp grow were compared with literature. The physiochemical parameters had measured on the 29th June, 16th July, 12th August and 4th October on the Dehtář pond. The followed physiochemical parameters were measured: concentration of oxygen (mg-l-1), temperature of water (°C), pH, transparency (m) and chlorophyll concentration (?g-l-1). It was used calibrated measuring device EXO2 and a Secchi disc. The pond was measured in two transects with focus on depth, inflow, outflow and feeding area. For better evaluation of the results it had included the continuous measurements data from Vltava River Authority, particularly the concentration of oxygen, temperature and light regime. The Dehtář pond is used mainly for intense fish-pond management. Fishery Hluboká manages on this pond. Stock of the pond is polyculture. Dominant fish is common carp, next for example grass carp, pike, pikeperch and catfish. The pond is regular fed, limed and fertilized. From those data, it has produced the spatial and temporal visualisation of basic physiochemical parameters in the pond. From the spatial visualisation follows that the quality of inflow water, depth of water, meteorological situation and position of feeding area had a significant influence on physiochemical parameters. From the temporal visualisation follows that the highest differences in our data were during temperature stratification on 29th June 2016. This day range of the pH was from 7.1 to 9.1. During the other days pH was just about 8. On 29th of June 2016 the range of the temperature was quite high. The temperature was from 19.8 °C to 24.8 °C. Oxygen deficits were very often on this pond. Oxygen deficits had big influence on the death of fishes. The concentration of oxygen went down under the limit values (0.5 mg-l-1) for 2 times during the Vltava River Authority measuring. The local places of low concentration of oxygen had located on the depth of 1.5 m for 25 times during the Vltava River Authority measuring. The Vltava River Authority regularly takes measurements on the Dehtář pond. It should be used for better management and for preventing the critical situation, particularly the drop of oxygen, which could harm the fish. It should be limited feeding, because of the often oxygen deficits.
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Effect of different descaling/skin removing methods on sensory properties and shelf life of common carp
VÁGNER, Martin
The present bachelor thesis studied microbiological quality, sensory attributes and customer preferences of common carp filet (Cyprinus carpio) descaled by different methods under two storage conditions. Fillets were processed by four descaling methods, namely: without skin, without scales, undercut scales and fillets of mirror carp (with skin). Moreover two types of storage conditions, air packed and vacuum packaged, were tested at 3.8 +- 0.5 ° C. Microbiological analyses were determined by total viable counts in logarithm of colony-forming units per gram (log CFU.g) on storage days 0, 3, 6 and 9. Furthermore, sensory analyses of fillets was classified and customer preferences were evaluated by using an anonymous questionnaire. In microbiological analyses, an increase of the total number of microorganisms with increasing storage time was observed. Microbial communities grew to between 2.3 - 2.69 log CFU.g-1 on the first day of fish processing (day 0) and 6.35 - 8.28 log CFU.g-1 on the last day of storage (day 9). Microbiological analysis showed that skinless fillets reached the lowest total number of microorganisms, regardless the type of packaging (air / vacuum packaged). Also sensory analyses showed that consistency and odour of carp fillets were influenced by packaging conditions as well as descaling methods. The best results in sensory evaluation achieved fillets without skin and undercut scales. The survey on consumer preferences of carp found out that 58.9 % of customers preferred scaly carp with undercut scales and processed to fillets. The results of present study show that different types of descaling methods combined with air / vacuum packaging can significantly prolong the shelf life of carp fillets.
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Quality of smoked products of economically important fish species
KORYŤÁK, Lukáš
The objective of this thesis was to test the environmental friendly additive substance, in particular sodium caseinate, which is not subject to designation "E" on the label of the product, which is unpopular among the consumers, and which would provide so-called a "higher value" to a product of economically important fish species in the Czech Republic, specifically the common carp (Cyprinus carpio), silver carp (Hypophthalmichthys molitrix) and the rainbow trout (Oncorhynchus mykiss).Determination of the influence of this additive on microbial and biochemical processes, and also on organoleptic properties of the selected smoked fish was another goal of the work. Three concentrations of this product were used for application in total, in particular 25, 50 and 100 g×kg-1. The results of this work confirmed that, due to caseinate (concentration of 100 g×kg-1) such losses of water were avoided, as observed in case of the control group, to which no additive product was applied, and which served for comparison with the groups treated with caseinate. General carp had an average loss of 12.9 % for the samples treated with sodium caseinate and 14 % for the control group. The silver carp white showed similar results. The group treated with caseinate lost 12.4 % in average, and the control group of approximately 14 %. The best results were recorded with the rainbow trout, which, due to caseinate withheld the largest amount of water, respectively, it did not lose so much of weight, in particular 15.9 % for sodium caseinate compared to 19.3 % measured in the control group, however these differences were not confirmed as statistically conclusive. As for the texture of the meat, tougher samples came out for the ones treated with sodium caseinate compared to the more brittle control group. In carp and trout no statistically noteworthy dissimilarity in stiffness of meat was proved between the control group and the group with the applied additive product. While these differences were significant in silver carp. While for silver carp were these differences significant. The control group showed clearly (p<0.05) lower stiffness compared to the group, to which the additive product was applied. Microbiological analysis was performed on the 7th day after smoking, and the values were in the range of 2×10 to 1.9×10^2 CFU×g-1. In the experiment, groups of test fish species did not show any statistically significant difference (p>0.05). Tests for the possible presence of Listeria monocytogenes in all of the smoked fish samples and the control group were negative. Nutrient composition was mainly focused on the basic nutrient components, which were the proteins, fats and carbohydrates. The control group did not show any significant differences compared to the group to which sodium caseinate was applied. The results from the consumers and sensory analysis by a panel of trained persons were very similar. No statistically significant differences between the group treated with caseinate sodium, and the untreated so called control group of smoked species of fish.
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Extending of shelf life of chilled fish products
PFLUG, Róbert
This diploma thesis was focused on the possibilities of extending the shelf-life of fish products by dipping containing seven commercial additives. ANTIBAK, MIC STAB, Bakont, SEA-F75, Misocarine LR, SAFE A Plus and AMX liquid. The effectiveness of these substances on the extending of shelf-life was evaluated on the basis of tests of TVC (total viable count), level of fat and protein oxidation, determination of nutritional parameters of muscle, and finaly sensory analysis. Experimental species were 2 important commodities for the Czech aquaculture rainbow trout (Oncorhynchus mykiss) and common carp (Cyprinus carpio). The project was divided into 6 sub-stages. During testing was the initial number of aditives (7) limited by stepwise selection for 2 preparations. Namely Bakont and AMX liquid, which were tested further on trout (filet with skin and scales) and carp (filets with skin without scales) chilled bulk and chilled packaged under vakuum. For trout was studied antimicrobial effect of dipping on eviscerated fish with the head with- or without gills. Treated trout fillets in bulk and vakuum-packed showed significantly less abundance of muscle mikroflora. In the case of carp fillets chilled bulk we can not say that the bath had influence on the CMP in meat. However, the combination of dipping and vakuum packaging was singnificantly different between the control and product Bakont. AMX liquid was not applied in this case in sufficient dose or in sufficient time to carp muscle. A positive finding is that the application of the aditives to the product "eviscerated trout with head" it does not matter, whether the gills are left in fish or not. However, in all cases the analysis of the presence of pathogens Escherichia coli, Salmonella spp. or Listeria monocytogenes were negative. From the results of sensory analysis can be concluded, that the substances contained in aditives are not reflected in the sensory properties of tested fish.
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Cryopreservation of common carp (\kur{Cyprinus carpio} L.) sperm under different freezing conditions
SOCHOROVÁ, Denisa
In the present study, we examined several cryoextenders previously used by several authors and various freezing protocols to determine the relative importance of each parameter on sperm freezing. The effects of controlled seeding and changes in cooling rate at different stages of freezing were also examined. Sperm samples from seven individual carp males were frozen in 0.5 ml straws by conventional freezing. Cooling rates were determined by monitoring the sample's internal temperature. We compared four freezing protocols, which involved placing sperm samples at various levels (1, 3, 6, and 9 cm) above the liquid nitrogen (LN) surface (corresponding to -190, -150, -110, and -70 °C, respectively) for 20 min followed by transferring the samples into LN. Freezing at 3 cm above the LN surface resulted in the highest motility (33 ? 8 %) and velocity (118 ? 9 ?m/s) of spermatozoa after thawing and diluting in swimming medium. We determined that -90 °C is an optimal temperature at which immersing the samples in LN does not affect sperm motility after thawing. The sperm motility of samples immersed in LN before or immediately after the crystallisation point (-16 °C) was 0 %. Motility of spermatozoa cryopreserved with or without a seeding procedure was not significantly different after thawing. Therefore, we hypothesise that supercooling the sample during the conventional freezing procedure is not the main damaging factor during carp spermatozoa cryopreservation.
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