نتایج جستجو برای: esox lucius

تعداد نتایج: 570  

Journal: :Folia parasitologica 2014
Anastasiia Grybchuk-Ieremenko Alexander Losev Alexei Yu Kostygov Julius Lukeš Vyacheslav Yurchenko

One thousand three hundred seventy three fish specimens of eight different species from the vicinity of Kyiv, Ukraine, were examined for the presence of trypanosomes and 921 individuals were found to be infected. The prevalence of infection ranged from 24% in freshwater bream, Abramis brama (Linnaeus), to 100% in spined loach, Cobitis 'taenia' Linnaeus. The level of parasitaemia also varied sig...

2008
S. Reschova D. Pokorova J. Hulova P. Kulich T. Vesely

The present study reports the results of virological survey in fish with an emphasis on the diseases included in the Czech National Legislation. Monitoring of fish both without symptoms and with a manifested disease was performed within this virological surveillance. Between January 1999 and December 2006, viral haemorrhagic septicaemia virus (VHSV), infectious haematopoetic necrosis virus (IHN...

Journal: :Ambio 2014
Göran Sundblad Ulf Bergström

Coastal development has severely affected habitats and biodiversity during the last century, but quantitative estimates of the impacts are usually lacking. We utilize predictive habitat modeling and mapping of human pressures to estimate the cumulative long-term effects of coastal development in relation to fish habitats. Based on aerial photographs since the 1960s, shoreline development rates ...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2007
Eric Edeline Stephanie M Carlson Leif C Stige Ian J Winfield Janice M Fletcher J Ben James Thrond O Haugen L Asbjørn Vøllestad Nils C Stenseth

Selective harvest of large individuals should alter natural adaptive landscapes and drive evolution toward reduced somatic growth and increased reproductive investment. However, few studies have simultaneously considered the relative importance of artificial and natural selection in driving trait changes in wild populations. Using 50 years of individual-based data on Windermere pike (Esox luciu...

2014
Johan Fahlman Göran Englund

The mechanisms behind speciation have been subject of debate for centuries. The presence of resource polymorphism has been discovered to play a significant part in this process, and has been proven to induce phenotypic and genetic divergence. Although resource polymorphism has been intensely studied during the last few decades, there is a gap of information as to why this can be observed in som...

2010
Robert Arlinghaus Shuichi Matsumura Robert ARLINGHAUS Shuichi MATSUMURA Ulf DIECKMANN

Traditional fisheries management theory supports aggressive exploitation of old and large fish to maximize a stock’s biomass production and yield. Here we present an age-structured fish population model with multidimensional density-dependence to test the hypotheses that protection of large, fecund individuals is beneficial for the population and selected fisheries variables and that effects of...

Journal: :Proceedings. Biological sciences 2006
Thrond O Haugen Ian J Winfield L Asbjørn Vøllestad Janice M Fletcher J Ben James Nils Chr Stenseth

The ideal free distribution (IFD) theory is one of the most influential theories in evolutionary ecology. It predicts how animals ought to distribute themselves within a heterogeneous habitat in order to maximize lifetime fitness. We test the population level consequence of the IFD theory using 40-year worth data on pike (Esox lucius) living in a natural lake divided into two basins. We do so b...

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