The objective of this study was to evaluate the effect of heavy metals, at environmentally relevant concentrations, on the immune response of rainbow trout. Trout were exposed for 30 d to cadmium chloride (CdCl2), mercuric chloride (HgCl2), or zinc chloride (ZnCl2) either individually or in combinations: CdCl2/HgCl2, CdCl2/ZnCl2, HgCl2/ZnCl2, or CdCl2/HgCl2/ZnCl2. Following the 30-d exposure, p...

Many Appalachian streams historically dominated by Brook Trout Salvelinus fontinalis have experienced shifts towards fish communities dominated by Rainbow Trout Onchorhynchus mykiss. We used empirical estimates of biomass and secondary production of trout conspecifics to evaluate species success under varied thermal regimes. Trout populations were sampled in 13 Appalachian streams from Maryland...

The rainbow trout (Oncorhynchus mykiss) is one of the most widely used fish species in aquaculture and physiological research. In the present paper, we report the first cloning, 3D (three-dimensional) modelling, pharmacological characterization and tissue distribution of two melanocortin (MC) receptors in rainbow trout. Phylogenetic analysis indicates that these receptors are orthologues of the...

Periods of high or fluctuating seawater temperatures result in several physiological challenges for farmed salmonids, including an increased prevalence and severity of cataracts. The aim of the present study was to compare cataractogenesis in Atlantic salmon (Salmo salar L.) and rainbow trout (Oncorhynchus mykiss) reared at two temperatures, and investigate whether temperature influences lens m...

Pit-1 is a pituitary-specific transcription factor responsible for activating growth hormone (GH) and prolactin genes. Here, we describe the isolation of a rainbow trout cDNA clone that contains the entire Pit-1 coding region. The deduced amino acid sequence contains 358 residues, encoding a 39-kDa protein. Comparison of the protein sequences of the rainbow trout and rat Pit-1 shows that the 16...

The susceptibility of 2 strains of rainbow trout Oncorhynchus mykiss, 1 from North America (TL) and 1 from Germany (GR), to Myxobolus cerebralis (the cause of salmonid whirling disease) was assessed following exposure to the infectious stages (triactinomyxons). Two laboratory experiments were conducted with age-matched rainbow trout of each strain. At the beginning of the study, the 2 trout str...

Background: Much has been written about introduced rainbow trout (Oncorhynchus mykiss) interbreeding and outcompeting cutthroat trout (Oncorhynchus clarkii). However, the specific mechanisms by which rainbow trout and their hybrids outcompete cutthroat trout have not been thoroughly explored, and the published data is limited to lotic ecosystems. Materials and Methods: Samples of rainbow trout ...

Despite the importance of predator recognition in mediating predator-prey interactions, we know little about the specific characteristics that prey use to distinguish predators from non-predators. Recent experiments indicate that some prey who do not innately recognize specific predators as threats have the ability to display antipredator responses upon their first encounter with those predator...

BACKGROUND Despite vaccination with a commercial vaccine with a documented protective effect against Vibrio anguillarum O1 disease outbreaks caused by this bacterium have been registered among rainbow trout at Danish fish farms. The present study examined specific serum antibody levels as a valid marker for assessing vaccination status in a fish population. For this purpose a highly sensitive e...

Flavobacterium psychrophilum is the causative agent of rainbow trout fry syndrome (RTFS), also called bacterial cold water disease (BCWD) in USA. Since being discovered in USA in the 1940s, the disease has spread to aquacultures worldwide [1]. Mortality rates as high as 90% have been reported in fry, although the mortality rate in Danish outbreaks average around 30–40%. Rainbow trout (Oncorhync...