The primary objectives of this study were: 1) to evaluate the movement patterns, habitat use, and survival of triploid grass carp Ctenopharyngodon idella stocked to control hydrilla Hydrilla verticillata in a riverine reservoir (Claytor Lake, Virginia), 2) to examine grass carp population dynamics and hydrilla growth dynamics in Claytor Lake to guide long-term management efforts, and 3) to describe the aquatic plant community in the New River upstream of Claytor Lake to assess the potential for alterations due to potential grass carp herbivory. Only 3% of radio-tagged grass migrated out of Claytor Lake during the 2-year study. Grass carp movement patterns were significantly correlated with temperature-, weather-, and habitat-related variables. Grass carp selected specific cove, shoal and tributary habitats colonized by hydrilla. First-year survival of grass carp was 44% in 2011, and 25% in 2012. Grass carp growth rates were rapid in 2011, but declined in 2012 concurrent with significant reductions in hydrilla abundance. Based on grass carp population dynamics observed in Claytor Lake, our stocking model predicted that hydrilla could be controlled through 2030 by a grass carp standing stock of 5-6 metric tons. We documented 12 plant species in the New River upstream of Claytor Lake, 9 of which are preferred plants for grass carp suggesting that the plant community could be altered if migration rates increase. Grass carp can be effective for managing hydrilla in riverine reservoirs; however, continued monitoring of grass carp population dynamics, migration rates, and vegetation abundance could facilitate greater precision in management efforts. / Master of Science

The objective of this thesis was to compare biometrical and slaughtering indicators of common carp crossbreeds using two different breeds of Amur mirror carp in performance testing. We applied top-crossing for the test establishment, using the Hungarian mirror carp (M2) on the maternal position. Males of Hungarian mirror carp (for the production of purebreed), Northern mirror carp (M72) and two breeds of Amur mirror carp (ALP ? bred in Pohořelice, ALV ? bred in Vodňany) were crossed on this breed and hybrids of scaly phenotype between Ropsha (ROP) and Tata carp (TAT) were used as a control group. The performance testing started in ponds (in the total of five localities) in the semi ? intensive way of management by releasing yolk sac fry (K0) and its subsequent rearing to the market size (K3). The performance test was completed in ponds after the third year of testing and the tested groups of fish were evaluated for biometrical and slaughtering indicators. In the overall evaluation of the edible parts of the body (processed body and fillets) by the ANCOVA method was not found a statistical difference among the mirror tested groups of fish. The only exception was the proportion of fillets without skin, which was significantly higher in the hybrid M2 x ALP than in breed M2, therefore I would not recommend this breed (M2) to commercial breeding. When comparing my results with other publications, the hybrid M2 x M72 could be used for commercial breeding together with the two hybrids of Amur mirror carp, who not only achieve high yield of edible parts of the body, but also the earlier tests confirmed higher growth, better survival and resistance to the KHV virus.

Aquaculture production is increasing annualy and wild fisheries for fishmeal production remain stagnant. As a consequence, extensive research has been deployed to reduce dietary fishmeal inclusion in feeds of farmed species. Usage of alternative protein sources derived from plants continues to increase with the most popular sources being oilseeds, legumes and cereal grains. The downside of these sources is that most of them could directly be used for human consumption arising legitimate criticism from voices referring to countries where protein shortages lead to malnutrition among the population. Jatropha curcas is a tropical oilseed with upcoming popularity for sustainable fuel sourcing. The plant is thought to thrive in semi-arid and arid areas, not just producing oil, but at the same time reclaiming previously eroded land for the local population. For these reasons, annual cultivation of Jatropha curcas is thought to rise over the next decades. After oil is extracted from the seed, the remaining press cake, is currently used as a fertilizer or energy source. This is mostly due to toxic phorbol esters that until recent- ly limited any nutritional applications. In 2011, a method to detoxify Jatropha press cake was developed and paved the way for nutritional research on the resulting detoxified Jatropha curcas kernel meal (JKM) to be launched. JKM offers very high protein content with a balanced amino acid composition suggesting opportunities for usage as a feedstuff in aquaculture diets. JKM further has higher mineral content than comparable oilseeds. However, potential anti-nutritional factors (ANFs) present in the meal could lead to impairment of nutrient availability or other adverse effects. Previous research has already started to evaluate JKM as a protein source for a variety of aquaculture species. This thesis attempts to further identify the potential of JKM as a protein source and assess the effects of JKM on the development of two model cultured teleost species, common carp (Cyprinus carpio) and Nile tilapia (Oreochromis niloticus), as they represent two of the most farmed species, particularly in the tropics. The work comprises growth trials on both species using fishmeal as a subject of replacement in solely fishmeal protein-based diets and on more practical fishmeal/plant protein-based diets. It engages with the effects of phytate, a prominent component of JKM with potential anti-nutritional attributes and commercially available phytase feed supplements to diminish these attributes, as well as oxalate, another plant-specific component with high concentrations in JKM and with limited attention in aquaculture nutrition research. Carp and tilapia showed varying results with different inclusion levels of JKM. For carp 50% fishmeal replacement was possible without losses in growth in diets where fishmeal was the only bulk protein source (Chapter 3.1), Tilapia showed slightly worse growth at a 30% replacement level (Chapter 3.2). A steep decline in growth could be observed when replacing 100% fishmeal with JKM in carp (Chapter 3.1), while tilapia showed no difference at that level compared to 30% replacement (Chapter 3.2). In practical diets, 100% of fishmeal could be replaced by JKM without any adverse effects on growth of carp (Chapter 3.3), while tilapia showed a slight, but significant linear negative correlation with higher inclusion levels of JKM (Chapter 3.4). Phytase addition in tilapia feeds was identified as having no obvious impact on growth in JKM based diets where enough available phosphorus was provided through mineral supplementation (Chapter 4.1). In JKM based diets where available phosphate was not added, phytase addition showed a tendency to increase growth and significantly increased mineral retention and decreased phosphorus effluent contamination (Chapter 4.2). Phytase application through pre-incubating JKM along with citric acid exerted a positive effect of growth on carp when fishmeal protein was replaced by 50% (Chapter 3.1). Phytase was further shown to completely hydrolyze phytate in vitro; however, incomplete hydrolysis was observed in vivo in tilapia (Chapter 4.3). Dietary soluble oxalate added to fishmeal based diets for carp showed better growth parameters, nutrient and mineral retention at inclusion levels 1.5% and higher (Chapter 5.1). For tilapia, a trial could demonstrate adverse effects of oxalate on potassium, calcium, manganese and zinc digestibilities, in this case without negative effects on growth (Chapter 5.2). For both, carp and tilapia, an impact of oxalate on lipid metabolism was evident, lowering body lipid content and blood cholesterol in inclusion levels from 1.5% or higher. JKM can become a valuable alternative to present dietary protein sources in aquaculture feeds. The nutritional attributes of JKM need further research, especially longer-term testing in a commercial scenario and application in commercially produced feeds. Results of this thesis pose a useful addition to previous research and can be referred to for realizing these next steps.

The aim of feed formulation in aquaculture is to supply a suitable diet that provides nutritional requirements at relatively low cost. Carbohydrates are the most economic energy source for animals compared to protein and lipid; however, fish have limited capacity for dietary carbohydrate utilization. Trivalent chromium is an essential micronutrient for carbohydrate metabolism in vertebrates. The primary objective of this thesis was to enhance understanding of the effects of organic and inorganic forms of Cr on carbohydrate utilization, growth performance, gene expression and activity of specific key liver enzymes in carp Cyprinus carpio. In addition, effects of dietary Cr on body composition, Cr tissue content, blood cells DNA damage, and tissue histopathology (liver and gut) were evaluated. The first experiment (Chapter 3) tested levels of dietary Cr (0, 0.2, 0.5, 1.0, 1.5, 2.0 mg Cr kg-1 as Cr chloride) to determine Cr requirement; the second experiment (Chapter 4) compared bioavailability of different forms of Cr (Cr chloride, Cr picolinate, and Cr yeast); and the third experiment (Chapter 5) evaluated different levels of Cr yeast (0.5, 1.0, and 2.0 mg Cr kg-1) on utilization of a starch or dextrin-based diet. A Cr supplementation of 0.5 mg Cr kg-1 (regardless of form of Cr) produced highest growth performance; whereas 2.0 mg Cr kg-1 did not differ from control. The 0.5 mg Cr kg-1 also enabled carp to utilize complex carbohydrates (e.g., starch) and did not affect final body composition. Only 2.0 mg Cr kg-1 caused DNA damage in blood cells and tissue damage (liver and gut histopathology). Cr content in whole body increased with dietary Cr, but Cr did not affect hexokinase gene expression. Overall, results indicate that Cr can improve growth performance of carp and that Cr supplementation can enhance utilization of carbohydrates in fish feed.

Carp aquaculture in South Asia suffers severely from a lack of genetic management, which has eroded the genetic quality of both captive and wild populations. Use of molecular markers, especially microsatellites, has revolutionized genetic management of hatchery stocks through its ability to detect kinship between individuals and hence in controlling level of inbreeding and loss of genetic diversity. In the present PhD work, microsatellite markers were applied to breeding programmes for silver carp (Hypophthalmichthys molitrix) and common carp (Cyprinus carpio) to study different genetic management aspects and new markers were generated from rohu (Labeo rohita). A set of newly isolated microsatellite markers from silver carp were characterized and two pentaplex PCR reactions were optimized to enable rapid genotyping of large number of individuals at 10 microsatellite loci. The utility of these markers in parentage, sibship and relatedness analysis were assessed by applying them to groups of fish with known relationship. These markers were used for parentage analysis in a breeding programme designed to estimate heritability of harvest weight and length in silver carp. Full- and half-sib families were created in three sets of partly factorial mating and all the families from each set were reared in communal ponds from very early life stages. With ten microsatellites 96.3% of the offspring could be assigned to a single family. Heritability estimates were found to be 0.65 ± 0.13 for weight and 0.50 ± 0.13 for length. High estimates of h2 suggested that this population should respond rapidly to selection for increased harvest size. Microsatellite markers were also applied to monitor the early stages of a mass selection programme in common carp (Cyprinus carpio). The selection was initiated from a base population synthesized from six different stocks. The selected individuals were divided to create two separate lines. The aims of this study were to monitor whether the stocks were represented in the intended proportions in the F1 selected populations, to investigate the relative contribution of families and its impact on effective population size and to identify any loss of molecular genetic variation. Five highly polymorphic microsatellites were used for parentage analysis of the selected fish to track stock and family contribution. Overall, large perturbations were observed in the relative contributions of two major stocks. Family contribution was also highly variable, causing the Ne to drop to below half the census size. A loss of 6.9%-12.2% of microsatellite alleles was observed but loss of heterozygosity was not very prominent. The replicate lines showed significant differences in allelic distribution after the first generation of selection, but not in genotypic distribution. Finally, 52 microsatellite markers were isolated from a partial genomic library of rohu using a selective hybridization protocol. Characterization of these markers resulted in 36 polymorphic loci, which will be useful in future work on conservation and management of both wild and captive rohu populations.

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.

The impact of vertical distribution of zoobenthos in a pond in response to the biomass stocking of carp ponds was tested in the Rod, Dobrá Vůle, Pohořelec, Haslauerteich and Neuteich ponds. Except for the Rod pond, various carp biomass was represented in all ponds. Sampling was conducted during the growing season (June and July), and outside the growing season (September). Physico-chemical parameters of water were measured for each sample. All samples were sorted by groups, counted and weighed. The results are presented in graphs. Zoobenthos density of the Dobrá Vůle, Haslauerteich and Neuteich ponds showed a rising tendency towards deeper parts of the pond sediment. The density of these ponds reached the maximum values in depths of 10-14 cm. This tendency was observed in the occurrence of midges in these ponds. The highest density of midges was observed in the Haslauerteich pond (1,687 individuals per square metre). The above-mentioned ponds were stocked by the common carp (K2-3). The largest density of the tubifexes in the Dobrá Vůle, Haslauerteich and Neuteich ponds was observed during the September sampling in the shallow parts of the sediment (0-6 cm). The maximum density was 1,031 individuals per square metre. On the Pohořelec pond, the occurrence of zoobenthos during both samplings was recorded only in the depth of 10-12 cm. Other representatives of zoobenthos were present in the Rod, Haslauerteich and Neuteich ponds. Larvae of Sialis and Chaoboridae were observed as well. The density and biomass was greater in the September sampling. We have noticed a greater settlement in various depths. Their maximum density was in the Haslauerteich pond (218 individuals per square metre).

Protocolos de sucesso para a maturação in vitro de oócitos de peixe são importantes, uma vez que é necessário para garantir uma fertilização bem sucedida, formação do zigoto, crescimento do embrião e seu completo desenvolvimento. Em algumas espécies, a eficiência deste processo ainda é muito baixa ou restrita a poucas substâncias que podem ser utilizadas. Assim, pesquisou-se a utilização de hormônios alternativos ao protocolo já existente para maturação in vitro de ovócitos de zebrafish. O objetivo foi avaliar a eficiência do extrato de hipófise de carpa (EHC), dos hormônios folículo estimulante (FSH) e luteinizante (LH) para fazer a maturação dos ovócitos estádio III de zebrafish. Os oócitos estádio III foram colocados em meio de cultivo Leibovitz modificado, suplementado com soro fetal bovino e adicionado o hormônio correspondente a seu tratamento (T1-controle; T2-16 μg/ml de EHC; T3- 32 μg/ml de EHC; T4- 48 μg/ml de EHC; T5- 64 μg/ml de EHC; T6- 80 μg/ml de EHC; T7- 0,5 μg/ml de FSH; T8- 0,5 μg/ml de LH e T9- 0,5 μg/ml de FSH e 0,5 μg/ml de LH). A taxa de maturação foi avaliada através da visualização da quebra da vesícula germinal (GVBD). Em todos os tratamentos houve maturação, embora o EHC tenha demonstrado taxas de maturação muito baixas (T2= 12,8%; T3=24,8%; T4=27%; T5=22,7%; T6=9,7%) e inferiores em relação a maior eficiência dos hormônios gonadotrópicos (T7=16%; T8=35%; T9=50%). Além disso foi possível verificar a viabilidade dos oócito através da fertilização in vitro do melhor tratamento (T9) com uma taxa de eclosão e desenvolvimento em larva de 60%. Os resultados da maturação in vitro utilizando estes indutores hormonais em oócitos estádio III de zebrafish mostraram-se promissores, e reforçam as perspectivas para o aprimoramento e uso desta técnica para produção in vitro de embriões viáveis. / Successful protocols for maturation of oocytes are important, as it is necessary for ensuring successful fertilization, zygote formation, embryo growth and full development. In some species the efficiency of in vitro maturation is still very low or is still restricted to a little amount of substances which can be used for the matter. Thus, we studied the use of alternative hormones to the existing protocol for in vitro maturation of zebrafish oocytes. The aim of this study was to evaluate the efficiency of the use of carp pituitary extract (CPE), the follicle stimulating hormone (FSH) and luteinizing hormone (LH) to oocyte maturation stage III of zebrafish. Oocytes stage III were placed in modified Leibovitz culture medium, suplemented with fetal bovine serum and added to the correnponding hormone treatment (T1-control; T2-16 g / ml of CHE; T3 32 g / ml of CHE, T4 - 48 g / ml of CHE; T5- 64 g / ml of CHE; T6- 80 g / ml of CHE; T7- 0.5 g / ml of FSH, T8 0.5 mg / ml of LH and T9- 0.5 g / ml of FSH and 0.5 mg / ml LH). The maturation rate was assessed by the germinal vesicle break down (GVBD). In all cases there was maturation, though the EHC has demonstrated fairly low maturation rate (T2= 12,8%; T3=24,8%; T4=27%; T5=22,7%; T6=9,7%) and lower in relation of the high efficiency presented by the gonadotropic hormones (T7=16%; T8=35%; T9=50%). In addition it was possible to verify the viability of the oocyte through IVF of the best treatment (T9) with a result of 60% of hatching and larvae development rate. The results of maturation in turn using this hormones in stage III oocytes of zebrafish proved promising, and enhance the prospects for improvement and use of this technique for in vitro production of viable embryos.

Tse Chui-ling. / "July 2004." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (p. 172-185). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web.

O aquarismo é uma atividade mundialmente difundida e um segmento extremamente grande da indústria de animais de estimação. O Brasil, em 2007, exportou o valor de US$ 5.871.576,73 em peixes. Devido à biologia dos peixes, todo seu manejo pode desencadear uma resposta fisiológica de estresse, que, dependendo da duração, tipo e espécie de manejo leva a uma resposta imunossupressora, que pode acarretar doença e morte aguda e consequentemente grande prejuízo à produção desses animais. O uso de imunoestimulantes, como suplementação dietética pode prover defesa inata e resistência a patógenos. O presente trabalho teve como objetivo avaliar a viabilidade da utilização de mananoligossacarídeo de levedo de cerveja (Saccharomyces cerevesiae), como imunoestimulante adicionado à ração oferecida a peixes da espécie Cyprinus carpio durante 45 dias. Para avaliar a imunidade dos peixes, foram feitas avaliações hematológicas periódicas e, no final do período determinado, os peixes foram desafiados imunologicamente com estresse e infectados com Aeromonas hydrophila. As carpas do grupo controle tiveram uma taxa de crescimento de 0,05 g/dia, conversão alimentar de 14,09 e eficiência protéica de 0,25, enquanto o grupo imunoestimulado obteve a taxa de crescimento de 0,11g/dia, conversão alimentar de 6,15 e eficiência protéica de 0,57. Não houve diferença estatística entre o resultado da hematologia dos animais do grupo controle e do grupo imunoestimulado. Dos animais infectados experimentalmente, 88% morreram em menos de 24 horas por choque endotóxico e, no exame post mortem, não houve diferença entre os grupos. A carpa que recebeu alimentação controle e foi infectada teve anemia macrocítica normocrômica, trombocitopenia, linfopenia, monocitose e aumento do número de CGE. A carpa que recebeu alimentação com MOS, foi infectada e sobreviveu, não apresentou alteração nos parâmetros hematológicos. A ração com MOS foi zootecnicamente melhor para a nutrição das carpas. Com base na taxa de sobrevivência e na avaliação hematológica, não há como responder se a ração suplementada com MOS foi imunologicamente melhor do que a ração controle. / The aquarium hobby is an activity wordwide spread and a segment extremely large of the pet industry. Brazil, in 2007, exported an amount of US$ 5.871.576,73 of fishes. Due to the biology of the fishes, all its management can trigger a physiological response leading to stress, that depending on the duration, type and specie, can conclude in immunosuppressive response, leading to disease and acute death, creating a great prejudice. The use of immunostimulants, as dietary supplementation may provide an innate defense against pathogens. This study aims to evaluate the feasibility of using mannan oligosaccharide of brewer yeast (Saccharomyces cerevesiae) as immunostimulants added to the feed for koi fishes (Cyprinus carpio) during 45 days. To evaluate the immunity of the fishes, periodic hematologic evaluations were made and at the end of the determined period, the fishes were immunologically challenged with stress and inoculation with Aeromonas hydrophila. The control group had a growth rate of 0,05g/day, feed conversion of 14,09 and protein efficiency ratio of 0,25, while the treatment group had growth rate of 0,11g/day, feed conversion of 6,15 and protein efficiency ratio of 0,57. The hematological results showed no statistical difference between the control group and immunostimulant group according. Analyzing the experimental infected animals, 88% died within 24 hours, due to endotoxic shock, and in the post mortem examination, there were no difference between groups. The koi that received control feed and it was infected had macrocytic normochromic anemia, thrombocytopenia, lymphopenia, monocytosis and increased of special granulocytic cells. The koi that received the MOS feed, was infected with A. hydrophila and survived, had no alteration on haematological parameters. The feed with MOS was zootechnical better than the control feed to carps. Based on the rate of survival and hematology, there are no possibility of answering if supplemented feed with MOS was immunologic better than control feed.