Small cyprinid fish, the topmouth gudgeon (Pseudorasbora parva Schlegel, 1842) is considered as an undesirable fish species because it represents an important food competitor for commercial non-predatory fishes. This study was performed under pond conditions (four ponds in South Moravia and two ponds in South Bohemia) during the growing seasons in 2006 {--} 2007. The purpose of my work was to determinate the level of food competition between topmouth gudgeon and common carp (Cyprinus carpio) as a dominating pond fish species. Food selectivity was evaluated using Ivlev´s electivity index (Jacobs, 1974). The level of food competition between common carp and topmouth gudgeon was used to evaluate the index of food similarity according to Shorygin (1952). The diet of topmouth gudgeon consisted mainly of chironomid larvae and zooplankton, mostly cladocerans (Daphnia, Bosmina), detritus and periphyton (Oscillatoria, Scenedesmus, Sphaerotilus). Macrophytes, copepods and Brachionus were also ingested by P.parva but in comparatively low proportions. In contrast, carp diet consisted mainly of bottom items including chironomid larvae, macrophytes and organic debris, mainly detritus and periphyton. The food items of lesser importance were dragon fly (Anisoptera) larvae, cladocerans (Bosmina, Daphnia) and ostracods. Topmouth gudgeon competed with common carp for chironomid larvae, periphyton and detritus, for zooplankton (mainly cladocerans Daphnia, Bosmina). The highest valuation the food competition was registered in fish from the Vracovický pond (South Moravia) and the Podsedek pond (South Bohemia), when it amounted from 24.02 to 34.78 % food similarity.

The carp Cyprinus carpio has a two-chambered swimbladder and excellent hearing. I explored the hypothesis that the anterior chamber, which connects to Weberian ossicles, is adapted for hearing by testing both chambers for material properties. I also determined displacement and auditory responses to mechanical strikes. Wall stress is higher in the posterior, strain in the anterior and modulus lower in the anterior chamber. Strikes increase pressure followed by a variable rebound that rapidly decays. Displacement and sound amplitude increase with hammer force, and amplitude is similar in both chambers for within chamber strikes but lower across chambers. Normalized for equivalent displacement, the anterior chamber produces a more intense sound. Stiffness and damping are greater for the anterior chamber, but sound spectra are similar. More intense sound production per unit of movement, greater damping and higher stiffness for the anterior chamber should all contribute to high-frequency auditory sensitivity.

Carp (Cyprinus carpio) are alien freshwater fish that are globally widespread and often associated with highly degraded freshwater ecosystems. This study explored carphabitat interactions that could contribute to the worldwide distribution of, and consequent ecological impacts by, carp. Particular emphasis was placed on the role of carp size in these interactions. One component of this study involved a field experiment that was used to quantify the effects of carp biomass density and size-structure on freshwater invertebrate communities and water quality. The treatments in this field experiment comprised different combinations of large (2 kg) and small (0.7 kg) carp, and low (330 kg.ha-1), intermediate (570 kg.ha-1) and high (650 kg.ha-1) biomass densities. Carp impacts were more carp size-dependent than described in previous studies. In particular, carp size was more important than carp biomass density in determining the concentration of total phosphorus and algal biomass. On the other hand, a more even mix of carp sizes increased total nitrogen. The zooplankton and macroinvertebrate taxa that were more abundant in the presence of carp were the taxa most able to avoid carp predation and tolerate habitat changes caused by carp benthivory. To complement the small-spatial scale field experiment, large-scale patterns of carp distribution, biomass density and recruitment were explored among the rivers of New South Wales (Australia) in relation to their physical habitat. In contrast to expectations, and although most recruitment probably occurred at lower-altitudes, the populations with a size structure and biomass density most likely to cause ecological degradation occurred at intermediate altitudes. Furthermore, the distribution of smaller carp (less than or equal to 100 mm, and less than or equal to 300 mm) indicated that the regulation of river flows does not always favour carp populations, particularly during drought conditions. Nevertheless, it was concluded in a review of the carp literature, which incorporated the findings of this study, that invasion by alien carp is most successful in streams with formerly highly variable flows that are now subject to flow regulation. Moreover, carp are likely to enhance their advantage in these waters through habitat modification.

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.

No description available.

Angl. resumé

Zwischen Herbst 2001 und Frühjahr 2002 wurden insgesamt 146 Speisekarpfen (Cyprinus carpio) parasitologisch untersucht. Die Speisekarpfen verteilten sich auf 60 einsömmrige sowie 86 zweisömmrige Speisekarpfen und stammten aus zwei Teichwirtschaften südlich von Leipzig (Sachsen). Insgesamt konnten sechs Protozoengattungen, sechs Helminthengattungen oder -arten und eine Arthropodenart (Argulus foliaceus) nachgewiesen werden. Dies waren im Einzelnen die Protozoenarten Apiosoma piscicola, Epistylis lwoffi, Ichthyobodo necator, Chilodonella cyprini, Ichthyophthirius multifiliis und eine Trichodina sp. Die Helminthen teilten sich in vier Trematoden (Gyrodactylus spp., Dactylogyrus extensus, Diplostomum spathaceum und Tylodelphys clavata), zwei Zestoden (Bothriocephalus acheilognathi und Khawia sinensis) und eine nicht näher differenzierbare Nematodenart (wahrscheinlich Capillaria brevispicula) auf. Differentialdiagnostisch konnten in den Beständen die fischpathogenen Bakterienarten Aeromonas hydrophila und A. salmonicida nachgewiesen werden. Klinische Anzeichen einer Infektion durch Pilze der Gattung Saprolegnia waren zu keinem Zeitpunkt bei den Speisekarpfen vorhanden. Die Umweltbedingungen in den Winterteichen waren im Gegensatz zu den letzten Jahren sehr konstant. So konnten große Schwankungen weder in der chemischen Zusammensetzung (Gesamthärte, Leitfähigkeit, Ammonium, Nitrit und Nitrat) noch in der Wassertemperatur im Untersuchungszeitraum beobachtet werden. Die Teiche waren nur wenige Wochen im Winter zugefroren. Die epidemiologische Entwicklung der Parasiten zeigte, dass die Gruppe der Protozoen zum Frühjahr teilweise explosionsartig anstieg, während die Prävalenz der Trematoden in diesem Zeitraum eher kontinuierlich anstieg bzw. im Falle der Zestoden auf annähernd konstantem Niveau verblieb. Seltene Funde waren die von Capillaria brevispicula und Argulus foliaceus, die in zu geringer Anzahl nachgewiesen wurden, um eine statistische Aussage über deren Epidemiologie zu erlauben. Als Fazit lässt sich aus den Ergebnissen meiner Untersuchung ableiten, dass sich stabile Haltungsbedingungen und gute Wasserqualtität positiv auf den Gesundheitszustand der Speisekarpfen auswirken. Mit dem regelmäßigen Umsetzen der Speisekarpfen ist lediglich eine Ausdünnung der Parasitendichte zu erreichen, wobei dies im Falle der beiden nachgewiesenen Bandwurmarten und der Karpfenläuse für die Erhaltung der Gesundheit des Bestandes allein nicht ausreichen wird. Sollten weiterhin keine zusätzlichen Arzneimittel für die Bekämpfung dieser Parasiten bei Lebensmittel liefernden Tieren zugelassen werden, ist daher meiner Meinung nach in Zukunft mit schweren wirtschaftlichen Einbußen zu rechnen. / A total of 146 carp (Cyprinus carpio) were examined between autumn 2001 and spring 2002. The carp were devided into two groups of 60 one-sommer-old and 86 two-sommer-old carp which were collected from two different Farms in the south of Leipzig (Saxony). Six protozoan genera, six helminthic genera or species, respectively, and one arthropod species (Argulus foliaceus) were detected. The protozoa Apiosoma piscicola, Epistylis lwoffi, Ichthyobodo necator, Chilodonella cyprini, Ichthyiophthirius multifiliis and one Trichodina sp. were found. The group of helminths comprised four trematode genera or species, respectively, Gyrodactylus spp. Dactylogyrus etxtensus, Diplostomum spathaceum and Tylodelphys clavata as well as two cestode species Bothriocephalus acheilognathi and Khawia sinensis, and one nematode species. The latter was detected in the intestine of very few carp and was designated as Capillaria brevispicula, but this was not confirmed. Furthermore two bacterial strains, Aeromonas hydrophila and A. salmonicida, were found in the stocks. Clinical signs of fungal infection caused by Saprolegnia spp. never were observed. In contrast to former years only minor differences in the environmental conditions like water temperature or chemical parameters (total hardness, salinity or ammonium compounds) were measured. Only a few weeks during winter the ponds were covered with ice. The epidemiological development of the protozoan parasites indicates a great increase of the prevalence in spring whereas the prevalence of trematode species increased during the whole examination period. No variability was found in case of cestodes. Findings of Capillaria brevispicula and Argulus foliaceus were very rare which excluded the statistical evaluation concerning the epidemiology of these parasites. The present study revealed a positive effect of rearing conditions and water quality on the general health status of carp. Pond management is an important tool to decrease parasite burden of fish, but no influence on cestode and argulid populations was observed. Therefore the introduction of further appropriate treatment is necessary to prevent high economic losses.

No description available.

Made available in DSpace on 2014-12-17T14:01:59Z (GMT). No. of bitstreams: 1 EmersonESM.pdf: 931852 bytes, checksum: f768665fe7e8aa27e4023b4def16f98d (MD5) Previous issue date: 2009-03-27 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Considering their commercial importance, as these are the species of freshwater fish more commercialized in Brazil, their occurence in different kinds of aquatic environments (lakes, rivers and dams) and for being tolerant to a wide range of variation of various physical parameters and chemical water, the fish species Oreochromis niloticus, Cyprinus carpio and Colossoma macropomum were chosen for this study, furthermore, to test the toxicity we used the herbicide Roundup. The fingerlings of tilapia (Oreochromis niloticus), commun carp (Cyprinus carpio) and tambaqui (Colossoma macropomum) were submitted to the herbicide roundup in the following concentrations: 0.0 (control); 18,06; 19,10; 20,14; 21,18 and 22,22 mg.L-1, 0.0 (control); 13,89; 14,86; 15,83; 16,81 and 17,78 mg.L-1, and 0.0 (control); 18,06; 19,10; 20,14; 21,18 and 22,22 mg.L-1, respectively, three for 96 hours. The LC50 - 96h for O. niloticus, C. carpio and C. macropomum was 21,63, 15,33 and 20,06 mg.L-1 of the herbicide roundup, respectively. The results show that this herbicide is classified as slightly toxic to the three species. The values of dissolved oxygen, pH and temperature recorded in the aquarium control and aquarium experimental of the three fish species have remained without significant variations during the tests, which reduces the possibility of death caused by sudden variations of these parameters during the 96 hours the experiment. The values of LC50 between different species of fish were observed, noting that the species O.niloticus, C. carpio and C. macropomum showed no expressive differences. The values of environmental risk of Roundup were calculated to obtain more stringent parameters in assessing the dangerousness of those on nontargets. The risk of environmental contamination by Roundup for the Nile tilapia, common carp, and tambaqui are low for the lowest application rate (1 L.ha-1) and depths (1.5 and 2.0 m). The dilution of 100%, the highest recommended dose (5 L.ha-1) and depths (1.5 and 2.0 m) the risk is moderate for the three species. The values of the Risk Ratio (QR) were greater than 0,1, indicating that the values of the CAE and LC50 are above acceptable levels and there is a need, this study, a refinement in ecotoxicological tests / Considerando a import?ncia comercial, por se tratarem das esp?cies de ?gua-doce mais comercializadas no Brasil, por ocorrerem em diversos tipos de ambientes aqu?ticos (lagos, rios e a?udes) e ainda por serem tolerantes a um amplo espectro de varia??o de diversos par?metros f?sicos e qu?micos da ?gua, as esp?cies de peixes Oreochromis niloticus, Cyprinus carpio e Colossoma macropomum foram escolhidas para este estudo com a finalidade de testar a toxicidade do herbicida roundup. Diante do exposto, o presente trabalho teve como objetivo determinar a toxicidade aguda e avaliar o risco de contamina??o ambiental dessas tr?s esp?cies de peixes pelo herbicida Roundup. Os alevinos de Til?pia do Nilo (Oreochromis niloticus), Carpa-comum (Cyprinus carpio) e Tambaqui (Colossoma macropomum) foram submetidos ao herbicida roundup nas seguintes concentra??es: 0,0 (controle); 18,06; 19,10; 20,14; 21,18 e 22,22 mg.L-1, 0,0 (controle); 13,89; 14,86; 15,83; 16,81 e 17,78 mg.L-1 e 0,0 (controle); 18,06; 19,10; 20,14; 21,18 e 22,22 mg.L-1, respectivamente, os tr?s por 96 horas. A CL50 96h para O. niloticus, C. carpio e C. macropomum foi de 21,63, 15,33 e 20,06 mg.L-1 do herbicida roundup, respectivamente. Os resultados obtidos demonstram que esse herbicida est? classificado como levemente t?xico para as tr?s esp?cies. Os valores de oxig?nio dissolvido, pH e temperatura registrados no aqu?rio controle e nos aqu?rios experimentais das tr?s esp?cies estudadas mantiveram-se sem varia??es significativas ao longo dos testes, o que reduz a possibilidade de mortalidade causada por varia??es bruscas desses par?metros, durante as 96 horas de experimento. Os valores das CL50 entre as diferentes esp?cies de peixes foram observadas, constatando que as esp?cie Oreochromis niloticus, Colossoma macropomum e Cyprinus carpio n?o apresentaram diferen?as expressivas. Os valores de risco ambiental do Roundup foram calculados para a obten??o de par?metros mais rigorosos na avalia??o da periculosidade desses sobre organismos n?o-alvos. O risco de contamina??o ambiental por roundup para a til?pia do Nilo, carpa-comum e tambaqui s?o baixos para a menor dose de aplica??o (1 L.ha-1) e nas profundidades (1,5 e 2,0 m). Na dilui??o de 100%, na maior dose recomendada (5 L.ha-1) e nas profundidades (1,5 e 2,0 m) o risco ? moderado para as tr?s esp?cies. Os valores de Quociente de Risco (QR) foram maiores que 0,1, indicando que os valores da rela??o CAE e CL50 est?o acima dos n?veis aceit?veis, havendo a necessidade de um refinamento nas an?lises ecotoxicol?gicas

The aim of the thesis was to evaluate the performance parameters of the breeds of common carp and its crossbreds by using the top-crossing. On the maternal position the Hungarian synthetic mirror carp line (HSM) was used. On this line, males of HSM, Telč mirror carp (TeL), Northern mirror carp (M72) and Amur mirror carp (AL) were crossed and a hybrid of Ropsha carp (ROP) and Tata carp (TAT) was used as their control group. Rearing of the tested groups was monitored from larval stage until their market size in ponds with a semi-intensive way of management in three localities (2 organisations). In the first year, each tested group was bred individually with internal control group of a different scaly covering phenotype in order to correct the influence of the environment on the weight achieved. In the second and the third year, all the groups were group-labelled and bred together in triplicate (three ponds) localities. In the individual stages of testing, the weight and the survival rate were recorded. Moreover, in the market size stage the biometric measurement and slaughtering value were evaluated. In the overall assessment of the results from all the localities carried out by the ANCOVA procedure, the highest weight at the K3 age was achieved by the hybrid HSM x AL (1413 {$\pm$} 31.5 g; Last square means {$\pm$} S.E.), whose weight was statistically comparable to the other hybrids (HSM x M72 a HSM x TeL). However, it was the only noticeably higher weight in comparison with the HSM (1257 {$\pm$} 31.5 g) with its ordinary heterosis effect of growth on the level of 12.4%. During the third year of testing, the survival ranged from 69.0 % in HSM x Tel to 73.4% in HSM x AL and the values were statistically comparable. The yield parameters (the proportion of the processed body, the proportion of filets with skin and the skinless ones) were similar in all the groups. In the previous periods of testing the results reflected the situation in the market size. As a result, it is concluded that preferably the hybrid HSM x AL could be exploitable in commercial breeding.