Věková struktura a růst divokých pstruhů obecných v závislosti na početnosti a charakteristice prostředí

Brown trout Salmo trutta L. is a fish species with high socio-economic value, which is favourable among anglers and a successful invader worldwide. The aim of this thesis is to explore environmental factors affecting body growth and survival of brown trout with emphasis on density dependent selection in juvenile life stages. This thesis is specifically focused on: (1) effect of population density on growth and survival with respect to a dynamic of a local group of individuals (papers I and II); (2) effect of inter-individual differences in behaviour on the relationship between individuals life-history traits and available resources (papers III and IV); (3) link between demo-genetic structure of population and growth and mortality rates of individuals (papers V, VI and VII). Datasets for this thesis were collected during a long-term mark-recapture study on wild brown trout population (2005-2011) in the catchment of the Otava River in Šumava National Park (Czech Republic) and a set of field and laboratory studies conducted on wild populations in streams on west coast of Sweden. In accordance with some previous studies, this thesis showed that growth of juvenile brown trout is negatively affected by population density. Nonetheless, this thesis reveals that the negative effect of density dependent...Pstruh obecný Salmo trutta L. je hospodářsky významná lososovitá ryba, která zároveň patří k nejúspěšnějším invazním druhům sladkovodních ryb na světě. Cílem této disertační práce bylo studium parametrů ovlivňujících rychlost růstu a přežívání jedinců tohoto druhu s důrazem na vliv populační hustoty na juvenilní stádia. Konkrétně je tato práce zaměřena na: (1) vliv hustoty populace na růst a přežívání jedinců s ohledem na dynamiku lokálních skupin jedinců (publikace I a II), (2) vliv rozdílného chování jedinců na vztah mezi růstem a přežíváním jedince v prostředí s variabilním rozložením zdrojů (publikace III a IV), (3) vztah mezi rychlostí růstu, mortalitou a demo-genetickou strukturou populace (publikace V, VI a VII). Údaje pro tuto práci pochází z dlouhodobého sledování populace pstruha obecného (2005 - 2011) v povodí řek Vydra a Křemelná v Národním Parku Šumava a kombinace terénních a laboratorních experimentů s divokými populacemi z toků na západním pobřeží Švédka. V souladu s přechozími studiemi tato práce ukazuje, že růst juvenilních jedinců je negativně ovlivněn populační hustotou. Nicméně negativní vliv početnosti může dle výsledků této práce být výrazně omezen známostí habitatu a ostatních jedinců ve skupině. Dále tato práce ukazuje, že i v rámci jedné populace pstruha obecného existují...Institute for Environmental StudiesÚstav pro životní prostředíFaculty of SciencePřírodovědecká fakult

Simulated pre-spawning catch and release of wild atlantic salmon (Salmo salar) results in faster fungal spread and opposing effects on female and male proxies of fecundity

Atlantic salmon are increasingly being released after capture by anglers. Yet, there are still unknown effects on the fish being subjected to the process of catch and release. Capture too close to spawning could have adverse effects on fish, and such data are important for setting appropriate closed seasons. This study examines how stressors related to catch and release experienced shortly before spawning affects adult mortality, vulnerability to Saprolegnia spp., and reproductive traits. Adult salmon were collected from the river Blackwater, Scotland, towards the end of their migration and were exposed to one of four protocols comprising exercise and air exposure of different durations. The experimental stressors increased the growth rate of the fungus Saprolegnia spp. over the body of the fish. Moreover, male salmon from the most disturbed group exhibited an increase in the maximum duration of their sperm motility. Lastly, females that experienced exercise and/or air exposure spawned at the usual time but with fewer eggs. These suggest that there may be benefits from preventing angling close to the time of spawning

IBEROAMÉRICA 1979 [Material gráfico]

Copia digital. Madrid : Ministerio de Educación, Cultura y Deporte. Subdirección General de Coordinación Bibliotecaria, 201

Guidelines for reporting methods to estimate metabolic rates by aquatic intermittent-flow respirometry

Interest in the measurement of metabolic rates is growing rapidly, because of the importance of metabolism in advancing our understanding of organismal physiology, behaviour, evolution and responses to environmental change. The study of metabolism in aquatic animals is undergoing an especially pronounced expansion, with more researchers utilising intermittent-flow respirometry as a research tool than ever before. Aquatic respirometry measures the rate of oxygen uptake as a proxy for metabolic rate, and the intermittent-flow technique has numerous strengths for use with aquatic animals, allowing metabolic rate to be repeatedly estimated on individual animals over several hours or days and during exposure to various conditions or stimuli. There are, however, no published guidelines for the reporting of methodological details when using this method. Here, we provide the first guidelines for reporting intermittent-flow respirometry methods, in the form of a checklist of criteria that we consider to be the minimum required for the interpretation, evaluation and replication of experiments using intermittent-flow respirometry. Furthermore, using a survey of the existing literature, we show that there has been incomplete and inconsistent reporting of methods for intermittent-flow respirometry over the past few decades. Use of the provided checklist of required criteria by researchers when publishing their work should increase consistency of the reporting of methods for studies that use intermittent-flow respirometry. With the steep increase in studies using intermittent-flow respirometry, now is the ideal time to standardise reporting of methods, so that - in the future - data can be properly assessed by other scientists and conservationists

Density dependent growth of brown trout Salmo trutta in oligotrophic streams

This thesis deals with the influence of population density on the growth of brown trout Salmo trutta. The research was carried out in the Šumava National Park in the river basins of two oligotrophic streams, the Vydra and the Křemelná. Data has been collected between years 2005 and 2010, every spring and autumn. Fish were caught via electrofishing and the length and weight of each individual were measured. Every individual caught was marked in a unique way. A few samples of scales were taken from some of them. The scales were fixed into laboratory slides, scanned and measured by graphic software. According to the differences between annual lamellas density, the age and the annual growth of individual's body length were estimated. Thanks to these results a negative relationship between the individuals' of age 1+ growth rate and the population density was confirmed. The importance of this thesis is mainly in comparing the influence of different spatial and time definitions of population on this relationship. The influence of the population density in spring (the initial time of the growth period) was proved to be essential for the growth rate. This fact suggests the importance of compensation growth intensity after the long period of winter for individual's general growth under conditions provided by..

Population density effect on behaviour of the brown trout regulated by fishery management and other civilization factors

Institute for Environmental StudiesÚstav pro životní prostředíFaculty of SciencePřírodovědecká fakult

Age structure and growth of wild brown trout in relation to population density and habitat quality

Brown trout Salmo trutta L. is a fish species with high socio-economic value, which is favourable among anglers and a successful invader worldwide. The aim of this thesis is to explore environmental factors affecting body growth and survival of brown trout with emphasis on density dependent selection in juvenile life stages. This thesis is specifically focused on: (1) effect of population density on growth and survival with respect to a dynamic of a local group of individuals (papers I and II); (2) effect of inter-individual differences in behaviour on the relationship between individuals life-history traits and available resources (papers III and IV); (3) link between demo-genetic structure of population and growth and mortality rates of individuals (papers V, VI and VII). Datasets for this thesis were collected during a long-term mark-recapture study on wild brown trout population (2005-2011) in the catchment of the Otava River in Šumava National Park (Czech Republic) and a set of field and laboratory studies conducted on wild populations in streams on west coast of Sweden. In accordance with some previous studies, this thesis showed that growth of juvenile brown trout is negatively affected by population density. Nonetheless, this thesis reveals that the negative effect of density dependent..

Věková struktura a růst divokých pstruhů obecných v závislosti na početnosti a charakteristice prostředí

Pstruh obecný Salmo trutta L. je hospodářsky významná lososovitá ryba, která zároveň patří k nejúspěšnějším invazním druhům sladkovodních ryb na světě. Cílem této disertační práce bylo studium parametrů ovlivňujících rychlost růstu a přežívání jedinců tohoto druhu s důrazem na vliv populační hustoty na juvenilní stádia. Konkrétně je tato práce zaměřena na: (1) vliv hustoty populace na růst a přežívání jedinců s ohledem na dynamiku lokálních skupin jedinců (publikace I a II), (2) vliv rozdílného chování jedinců na vztah mezi růstem a přežíváním jedince v prostředí s variabilním rozložením zdrojů (publikace III a IV), (3) vztah mezi rychlostí růstu, mortalitou a demo-genetickou strukturou populace (publikace V, VI a VII). Údaje pro tuto práci pochází z dlouhodobého sledování populace pstruha obecného (2005 - 2011) v povodí řek Vydra a Křemelná v Národním Parku Šumava a kombinace terénních a laboratorních experimentů s divokými populacemi z toků na západním pobřeží Švédka. V souladu s přechozími studiemi tato práce ukazuje, že růst juvenilních jedinců je negativně ovlivněn populační hustotou. Nicméně negativní vliv početnosti může dle výsledků této práce být výrazně omezen známostí habitatu a ostatních jedinců ve skupině. Dále tato práce ukazuje, že i v rámci jedné populace pstruha obecného existují...Brown trout Salmo trutta L. is a fish species with high socio-economic value, which is favourable among anglers and a successful invader worldwide. The aim of this thesis is to explore environmental factors affecting body growth and survival of brown trout with emphasis on density dependent selection in juvenile life stages. This thesis is specifically focused on: (1) effect of population density on growth and survival with respect to a dynamic of a local group of individuals (papers I and II); (2) effect of inter-individual differences in behaviour on the relationship between individuals life-history traits and available resources (papers III and IV); (3) link between demo-genetic structure of population and growth and mortality rates of individuals (papers V, VI and VII). Datasets for this thesis were collected during a long-term mark-recapture study on wild brown trout population (2005-2011) in the catchment of the Otava River in Šumava National Park (Czech Republic) and a set of field and laboratory studies conducted on wild populations in streams on west coast of Sweden. In accordance with some previous studies, this thesis showed that growth of juvenile brown trout is negatively affected by population density. Nonetheless, this thesis reveals that the negative effect of density dependent...Katedra ekologieDepartment of EcologyFaculty of SciencePřírodovědecká fakult

Age structure and growth of wild brown trout in relation to population density and habitat quality

Brown trout Salmo trutta L. is a fish species with high socio-economic value, which is favourable among anglers and a successful invader worldwide. The aim of this thesis is to explore environmental factors affecting body growth and survival of brown trout with emphasis on density dependent selection in juvenile life stages. This thesis is specifically focused on: (1) effect of population density on growth and survival with respect to a dynamic of a local group of individuals (papers I and II); (2) effect of inter-individual differences in behaviour on the relationship between individuals life-history traits and available resources (papers III and IV); (3) link between demo-genetic structure of population and growth and mortality rates of individuals (papers V, VI and VII). Datasets for this thesis were collected during a long-term mark-recapture study on wild brown trout population (2005-2011) in the catchment of the Otava River in Šumava National Park (Czech Republic) and a set of field and laboratory studies conducted on wild populations in streams on west coast of Sweden. In accordance with some previous studies, this thesis showed that growth of juvenile brown trout is negatively affected by population density. Nonetheless, this thesis reveals that the negative effect of density dependent..

Energy costs of catfish space use as determined by biotelemetry.

Animals use dispersed resources within their home range (HR) during regular day-to-day activities. The high-quality area intensively used by an individual, where critical resources are concentrated, has been designated as the core area (CA). This study aimed to describe how animals utilize energy in the HR and CA assuming that changes would occur according to the size of the used areas. We observed energetic costs of space use in the largest European freshwater predator catfish, Silurus glanis, using physiological sensors. Catfish consumed significantly more energy within the CA compared to the rest of the HR area. In addition, energetic costs of space use within a large area were lower. These results generally indicate that utilization of larger areas is related to less demanding activities, such as patrolling and searching for new resources and mates. In contrast, fish occurrence in small areas appears to be related to energetically demanding use of spatially limited resources