Consumer preference for commercially reared fish products that resemble their wild counterparts has resulted in the supplementation of pigments called carotenoids into aquafeeds to promote a pink-red colour in the flesh of salmonid fish. To date synthetic forms of these pigments have been commonly utilised to achieve this desired colouration, with the carotenoid astaxanthin being the regular choice for the feed manufacturer. However, increase in consumer demand for farmed fish products reared on natural feed additives has evoked an interest in natural sources of astaxanthin that could be successfully used to pigment salmonid fish efficiently. In the current study, the microalga Haemalococcus pluvialis has been assessed as a potential feed supplement to pigment the flesh of rainbow trout (Oncorhynchus mykiss). More specifically, those natural characteristics that may well limit the absorption and utilisation of astaxanthin from this source have been assessed individually and discussed from a physiological standpoint. The cell wall of Haemalococcus pluvialis when cracked efficiently presents no limitation to the absorption and utilisation of astaxanthin from this source. Indeed, the cell wall remnants help to prevent oxidation of astaxanthin in the feed compared to cell wall free extracts of carotenoid from the same source. However, esterified astaxanthin (which this algae predominantly contains) is not absorbed as efficiently as unesterified synthetic astaxanthin. Furthermore, the extent of esterification is negatively related to the absorption of astaxanthin. Regional variation in ester hydrolysis along the gastrointestinal tract combined with gut transit time of the ingested feed may explain these limitations. However, despite limitations in absorption, the muscle deposition of astaxanthin supplied as esters does not significantly differ from the unesterified form. The optical purity of astaxanthin esters from this source does not prejudice the final deposition of astaxanthin in fish tissues. An in vitro model has been developed to assess the absorption of astaxanthin at the intestinal level in salmonid fish in order to define absorption characteristics of carotenoids under different abiotic and biotic conditions. The absorption of astaxanthin seems to occur in a linear passive manner into the intestinal tissue. Although size of the fish does not affect the absorption of astaxanthin, temperature does have a significant effect. Although there were no significant differences in absorption between Atlantic salmon (Salmo salar) and rainbow trout, absorption tended to be greater in the latter species and merits further study.

No description available.

A rainbow trout (Slamo gairdneri Richardson) population of IPN virus carriers was studied over a one-year period using both homogenisatian and co-cultivation for virus isolation. The percentage of virus-yielding fish was high between March and June but then declined. This was diametrically opposite to the trend in the serum antibody levels indicating that the marked humoral immune response resulted in a very significant reduction in the virus titres. The highest isolation rate was obtained from the kidneys after co-cultivation (from seventeen of the twenty-three virus-positive fish) underlining the very high sensitivity of this recently developed method for virus detection. Twelve of the twenty-three virus-positive fish yielded virus from the pyloric caeca after homogenisation. Virus was occasionally isolated from the faeces indicating that this may well be a possible avenue for horizontal transmission of the virus. No virus was ever detected in gonadal tissue. The virulence of the rainbow trout virus was enhanced in various ways and used to infect tilapia Oreochromis spilurus Gunther of different ages through a variety of routes. Fry infected by direct immersion, orally and by force feeding showed little or no signs of infection. Intraperitoneally and intramuscularly injected fingerling and adult fish developed marked haemorrhaging, severe loss of skin mucus and up to 50% mortalities were recorded. Gross pathology included enlarged and liquifying liver, gastroenteritis and mild brain haemorrhaging. Histopathologically there was extensive cellular vacuolation and degeneration as well as marked leucocytic infiltration in the liver, intestine and swimbladder. Eosinophilic granule cell infiltration of the intestinal wall was also very prominent. Virus was recovered from several organs and determination of virus titres revealed that active viral replication had occurred in the tilapia tissues, a finding further supported by electron microscopical evidence. The fish showed a clear humoral antibody response.

A luminescence-based detection system was developed to study changes in the survival and activity of cells following release from moribund and dead fish. <I>A.salmonicida</I> was chromosomally marked with the genes encoding bacterial luciferase, originally isolated from <I>Vibrio harveyi</I>. Characterisation of the growth and luminescence of the <I>lux</I>-marked strain demonstrated that light was directly proportional to cell biomass concentration during logarithmic growth. The survival of <I>lux</I>-marked and wild type <I>A.salmonicida</I> strains was investigated in sterile sea water at 4°C. The number of culturable cells declined rapidly, but the total number of cells remained relatively constant, suggesting <I>A. salmonicida</I> entered a nonculturable state. The survival of <I>lux</I>-marked <I>A. salmonicida</I> did not significantly differ from that of the wild type strain. A small number of cells remained culturable throughout starvation experiments and luminometry confirmed that the <I>lux</I>-marked cells were metabolically active, possibly surviving by cryptic growth. The viability of putative dormant cells could not be established since these cells could not be reactivated following the addition of a range of substrates. The <I>lux</I>-marked <I>A.salmonicida</I> strain was pathogenic only when injected at high doses. This poor virulence was probably due to loss of the proteinaceous A-layer which is responsible for hydrophobic cell interactions and cell defence against lytic agents. This prevented further studies aimed at determining the virulence of nonculturable cells using this strain. Preliminary experiments indicated the potential of the <I>lux</I>-marked system for studying vertical transmission of <I>A. salmonicida</I>. The main sites for attachment of the <I>lux</I>-marked strain were the gill and skin/mucus regions. Identical results were obtained using a wild type <I>virulent A. salmonicida</I> strain, but significantly higher numbers of cells were recovered from fish tissue.

The use of carotenoid pigments as an archive of feeding behaviour and thus as environmental markers was tested using eggs and juveniles of sea trout and brown trout (Salmo trutta L.) invertebrates from the River Don and ectoparasitic lice (Lepeophtheirus salmonis Kroyer) of Atlantic salmon (Salmo salar L.). Carotenoids were analysed by normal phase high performance liquid chromatography (HPLC) and the resulting peaks examined in multivariate analyses. Analysis of trout eggs of known parentage suggested that the pigment profile of each egg reflects the migratory history of the maternal fish and it is also representative of the entire egg batch. With the same method, eggs of unknown or disputed parentage could be identified as those of sea trout, brown trout or salmon. Diagnostic properties permitting identification were high amounts of astaxanthin in sea trout eggs; while the presence of lutein, zeaxanthin and a greater number of carotenoid peaks were indicative of brown trout eggs. In hatchery experiments it was established that the diagnostic maternal pigment fingerprint is identifiable for some 1300&deg;d post fertilisation. In this time the majority of carotenoids are metabolised to astaxanthin esters and exogenous feeding will have begun. Muscle tissue carotenoids of juvenile trout in the River Don clearly separated 0+ trout from 1+ fish. The former arrange in a single discrete cluster on the basis of pigmentation, suggesting a common diet throughout the river catchment. Older parr show a specialist diet typical to each region but different from fry, indicating a shift in diet acquisition throughout early life stages. Pigment analysis of stream-living invertebrates and one terrestrial invertebrate revealed that all, except the terrestrial ear-wig, Rhabdiopteryx sp., Gammarus sp. and Leuctra sp., provide a homogeneous pigment profile. In contrast, Gammarus sp. was found to be the supplier of the greatest relative amount of astaxanthin, lutein and zeaxanthin. The diagnostic potential of carotenoids in sea lice was explored in samples taken from wild and farm Atlantic salmon fed on an artificial diet. Astaxanthin and canthaxanthin, which are pigments diagnostic of a natural and synthetic diet respectively, were detected. The ratio of canthaxanthin-like pigment to astaxanthin (C:A ratio) was 45:1 in farm lice and 8:1 in wild lice. Carotenoid content therefore could potentially be used as a tracer of origin of sea lice in epidemiological investigations.

Orientador: Reinaldo José da Silva / Banca: Vanessa Doro Abdallah Koslowski / Banca: Fabio Hideki Yamada / Banca: Sérgio Henrique Canello Schalch / Banca: Cristina Fátima Meldau de Campus / Resumo: A região do Médio Rio Paranapanema, no Estado de São Paulo, é a primeira em produtividade e a segunda em produção de peixes em cativeiro. Em 2002, a região possuía 30 tilapicultores que utilizavam tanques-rede instalados nos reservatórios. A perspectiva para essa modalidade de piscicultura em tanques-rede é do aumento do número de produtores nessa região, com a implantação de unidades processadoras, aumentando a cadeia produtiva deste novo agronegócio, bem como a implantação de novos parques aquícolas. A atividade está se expandindo nestes reservatórios e pelo menos 40 espécies de peixes tem sido usada nos sistemas de tanques-rede, com destaque para a espécie exótica Oreochromis niloticus. A tilápia do Nilo O. niloticus é a espécie de peixe exótica mais utilizada em águas continentais brasileiras em função da sua rusticidade, crescimento rápido, adaptação ao confinamento, hábito alimentar onívoro e fácil manejo reprodutivo em cativeiro, o que confere a ela um grande potencial para a aquicultura brasileira. No entanto, este crescimento dos tanques-rede para a criação de tilápias tem trazido nos últimos anos riscos aos reservatórios, como alterações na comunidade residente e na qualidade da água, tornando os ambientes mais eutrofizados. Atualmente existe uma carência muito grande de estudos parasitológicos aplicados aos peixes cultivados em tanques-rede nos reservatórios. Além disso, poucos estudos tem considerado a influência dos tanques-rede sobre a parasitofauna dos peixes associados a esse sistema de cultivo. Com o aumento da piscicultura, ocorre também uma degradação da água adjacente aos tanques-rede, facilitando o surgimento de diversas doenças. Atualmente, as pisciculturas vêm enfrentando diversos problemas relacionados à sanidade dos animais em cativeiro... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The Middle Paranapanema River, State of São Paulo, is the first in productivity and the second in production of fish in farmed. In 2002 this region had 30 farmers that used cages with tilapia in the reservoirs. The perspective for this activity of fish farming in cages is increasing in number of farmers in this region, the establishment of processing units, increasing the production chain of this new agribusiness as well as the implementation of new aquaculture parks. The activity is expanding in these reservoirs and at least 40 fish species have been used in cages systems, especially the exotic Oreochromis niloticus. O. niloticus is the most fish species used in Brazilian inland waters due to its hardiness, fast growth, adaptation to confinement, omnivorous and easier handling breeding in captivity, which gives it great potential for aquaculture in Brazil. However, this growth of the cages to the fish farm in recent years has brought risks to the reservoirs, such as changes in community and water quality, becoming the environments more eutrophic. Currently, there is a major lack of parasitological studies applied to fish reared in cages in the reservoirs. Moreover, few studies have considered the influence of the cages on the parasite fauna of fishes associated with this system of production. With the increase in fish farming, there is also a degradation of water adjacent to the cages, facilitating the emergence of various diseases. Hence, fish farms have been facing various problems related to the health of animals in captivity, which has generated significant losses and, consequently, a decrease in profit for the producer. Thus, early diagnosis of parasites involved in aquaculture activities and their influence on... (Complete abstract click electronic access below) / Doutor

Made available in DSpace on 2014-06-11T19:35:42Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-08-29Bitstream added on 2014-06-13T20:26:41Z : No. of bitstreams: 1 zica_eop_dr_botib.pdf: 1952532 bytes, checksum: 30631f946742404f6234cee295b5bdb0 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A região do Médio Rio Paranapanema, no Estado de São Paulo, é a primeira em produtividade e a segunda em produção de peixes em cativeiro. Em 2002, a região possuía 30 tilapicultores que utilizavam tanques-rede instalados nos reservatórios. A perspectiva para essa modalidade de piscicultura em tanques-rede é do aumento do número de produtores nessa região, com a implantação de unidades processadoras, aumentando a cadeia produtiva deste novo agronegócio, bem como a implantação de novos parques aquícolas. A atividade está se expandindo nestes reservatórios e pelo menos 40 espécies de peixes tem sido usada nos sistemas de tanques-rede, com destaque para a espécie exótica Oreochromis niloticus. A tilápia do Nilo O. niloticus é a espécie de peixe exótica mais utilizada em águas continentais brasileiras em função da sua rusticidade, crescimento rápido, adaptação ao confinamento, hábito alimentar onívoro e fácil manejo reprodutivo em cativeiro, o que confere a ela um grande potencial para a aquicultura brasileira. No entanto, este crescimento dos tanques-rede para a criação de tilápias tem trazido nos últimos anos riscos aos reservatórios, como alterações na comunidade residente e na qualidade da água, tornando os ambientes mais eutrofizados. Atualmente existe uma carência muito grande de estudos parasitológicos aplicados aos peixes cultivados em tanques-rede nos reservatórios. Além disso, poucos estudos tem considerado a influência dos tanques-rede sobre a parasitofauna dos peixes associados a esse sistema de cultivo. Com o aumento da piscicultura, ocorre também uma degradação da água adjacente aos tanques-rede, facilitando o surgimento de diversas doenças. Atualmente, as pisciculturas vêm enfrentando diversos problemas relacionados à sanidade dos animais em cativeiro... / The Middle Paranapanema River, State of São Paulo, is the first in productivity and the second in production of fish in farmed. In 2002 this region had 30 farmers that used cages with tilapia in the reservoirs. The perspective for this activity of fish farming in cages is increasing in number of farmers in this region, the establishment of processing units, increasing the production chain of this new agribusiness as well as the implementation of new aquaculture parks. The activity is expanding in these reservoirs and at least 40 fish species have been used in cages systems, especially the exotic Oreochromis niloticus. O. niloticus is the most fish species used in Brazilian inland waters due to its hardiness, fast growth, adaptation to confinement, omnivorous and easier handling breeding in captivity, which gives it great potential for aquaculture in Brazil. However, this growth of the cages to the fish farm in recent years has brought risks to the reservoirs, such as changes in community and water quality, becoming the environments more eutrophic. Currently, there is a major lack of parasitological studies applied to fish reared in cages in the reservoirs. Moreover, few studies have considered the influence of the cages on the parasite fauna of fishes associated with this system of production. With the increase in fish farming, there is also a degradation of water adjacent to the cages, facilitating the emergence of various diseases. Hence, fish farms have been facing various problems related to the health of animals in captivity, which has generated significant losses and, consequently, a decrease in profit for the producer. Thus, early diagnosis of parasites involved in aquaculture activities and their influence on... (Complete abstract click electronic access below)

Breeding of European bison (Bison bonasus) in the Czech Republic has begun to expand recently. The main aim of this graduation theses is to aquaire foreign information of this European breed and map breeding of this species in our country. Furthermore this thesis includes description of breeding European bison on one specific farm in Radany in South Bohemia and monitoring of ethologic knowledge of this certain herd. Bisons are kept in semi-natural conditions on the farm in the area of 14 ha. The basic herd of bisons forms 13 heads of Low-Caucasus genetic line. This part concludes with presentation of information boards of nature trail which is part of the Radany farm.

A one-year study was conducted in the Central Coast of California at a commercial vineyard to evaluate the effect of supplemental irrigation on dry-farmed Vitis vinifera L. cv. Zinfandel with varying vine ages during the 2021 growing season. The experimental block was historically dry-farmed on own-rooted Zinfandel vines, older vines were replaced as production quality decreased with a genetically identical scion grafted onto St. George (Vitis vinifera Scheel) rootstock. Six total treatments were included in this study, with Young vines (5 to 12 years old), Old vines (40 to 60 years old), and Control (2:1 ratio of old to young vines, and representation of the block). Each vine age treatment included both non-irrigated and irrigated vines, the total vine sample contained half irrigated and half non-irrigated. Irrigation was manually applied at véraison and véraison + 4 weeks, based on age-specific ETc, and to replenish 95% ETc. Results indicated no significant changes in phenological progression, leaf senescence, and physical berry analysis caused by supplemental irrigation during key developmental stages. Vine age was the primary driver of significant variation observed for most parameters. However, irrigated vines had slightly higher phenological progression leading up to harvest, although not statistically significant. Due to this minor trend, irrigated vines in each vine age group were harvested before the non-irrigated vines starting with young, control, and old vines. Additionally, lower leaf water potential was found at pre-dawn during the second irrigation application at véraison + 4 weeks. Applying supplemental irrigation during the growing season resulted in no significant impacts on vine performance. Results suggest the potential for implementing a dry-farmed management in vineyards to help adapt to climate changes and water scarcity issues.

Atlantic salmon (Salmo salar L.) has been domesticated since the 1960s and has undergone over 10 generations of artificial selection for economically important traits. As a result, domesticated salmon have diverged with respect to a number of phenotypic, genotypic and behavioural traits from their wild counterparts. Since the selection pressures that are present in the wild differ greatly from the ones that shape salmon under culture conditions, domesticated salmon stocks are considered to be maladapted to natural conditions. Despite strict regulations, insoluble issues pertaining to large-scale cage rearing of farmed fish mean that there is a continuous presence of farm escapees in the wild. Gene flow from escapees has been perceived as a factor in the decline of wild populations, suggested to occur through disruption of local adaptation. This study aims to improve understanding of the genetic differences between wild and domesticated stocks by comparing the transcriptomes of Figgjo (wild) and Mowi (domesticated) strains. A series of common garden experiments have been performed, utilizing pure and reciprocal hybrid crosses of the wild and domesticated stocks, reared under two different conditions and sampled at four time points and three distinct life stages (embryo, sac-fry and feeding fry). Microarray interrogations were performed employing a 44K custom microarray design to identify genes and gene pathways that are differentially expressed between the stocks. KEGG-based functional analyses have been implemented using different gene set enrichment packages, and dominance and additive parameters were calculated from normalized expression values to predict the mode of heritability of the genes identified as differentially expressed between stocks. Most biological functions represented in wild and domesticated crosses were consistent across life stages and environments. The transcriptomic differences detected between stocks in multiple developmental stages likely reflected adaptations to selection pressures differing between natural and aquaculture environments. Down-regulated environmental information processing and immune and nervous system functions in domesticated vs. wild fish may be due to local adaptation to captivity. These included reduced information acquisition and processing systems, altered stress responsiveness and changes in feeding behaviour. In line with the resource allocation theory of production trait animals, reduced immune function was coupled with increased expression of growth and development related pathways in domesticated salmon, compared to wild counterparts. Although there is support for this trade-off in all life-stages, resource allocation showed a shift over time; possibly reflecting variation in the utilization of energy sources during the transition from endogenous to exogenous feeding. Differences in cell communication and signalling pathways between wild and domesticated stocks, associated with organogenesis during the embryo stage, reflect sampling time and are indicative of altered organ development in response to domestication. Stress responses common across stocks included the down-regulation of cellular processes, including cell cycle and meiosis, and genetic information processing, such as replication and repair, transcription and translation pathways, probably reflecting the reallocation of energy resources away from growth and towards the restoration of homeostasis. Moreover, the mobilization of energy to cover the increased demands of maintaining homeostasis was indicated by the up-regulation of some metabolic pathways, mostly involved in energy, lipid and carbohydrate metabolism in response to stress. The analysis also revealed cross-specific stress responses, including indicators of a non-additive stress response in hybrid crosses. Most differentially expressed transcripts exhibited additive (31-59%) or maternal dominant (19-33%) inheritance patterns, although maternal over-dominance (23-26%) was also significant in the embryo stage. The mode of heritability of some immune transcripts was suggestive of maternal environmental influence having been affected by aquaculture. This study has demonstrated that biological functions affected by domestication include those associated with allocation of resources, involve reduction of information acquisition and processing systems and may lead to loss of local adaptation to wild conditions. Since such changes may affect key systems, such as immunity and responsiveness to stress, they can potentially have serious negative consequences under natural conditions. Transcriptomic differences observed between wild and domesticated stocks primarily exhibited additive and maternal dominant inheritance modes. Since gene-flow from farmed fish can be frequent and primarily concerns farmed females, this suggests that introgression due to repeated large scale escape events has the capacity to significantly erode local adaptation.