background: there are different activating salt solutions for sperm induction of rainbow trout (oncorhynchus mykiss) under artificial spawning condition, although some uncertainties are associated with the performance. objectives: this study was conducted to consider the effects of different concentration of calcium and magnesium ions and change of ph in the billard salt solution on sperm motil...

Physiological and biochemical factors affecting carotenoid utilization in salmonid fish. Gregory Ian Page Carotenoid utilization in rainbow trout (Oncorhynchus mykiss Walbaum) and Atlantic salmon (Salmo sa/ar L.) has been investigated with respect to tissue distribution of carotenoids and the role of the liver on the bioavailability of the lipid soluble carotenoids, astaxanthin and canthaxanthi...

Estrogen hormones interact with cellular ERs to exert their biological effects in vertebrate animals. Similar to other animals, fishes have two distinct ER subtypes, ERα (NR3A1) and ERβ (NR3A2). The ERβ subtype is found as two different isoforms in several fish species because of a gene duplication event. Although predicted, two different isoforms of ERα have not been demonstrated in any fish s...

In rainbow trout the magnitude of the cortisol response to stress shows both consistency over time and a moderate to high degree of heritability, and high responding (HR) and low responding (LR) lines of rainbow trout have been generated by individual selection for consistently high or low post-stress cortisol values. Using 2nd and 3rd generation fish, we tested the hypothesis that differential...

—In response to a petition to list Great Basin redband trout (subspecies of rainbow trout Oncorhynchus mykiss) as threatened or endangered, the U.S. Fish and Wildlife Service conducted a status review in 1998. To support that review, we conducted a survey of the abundances of redband trout in each of six subbasins of the Great Basin that included the states of Oregon, California, and Nevada. We...

Wildfire and debris flows are important physical and ecological drivers in headwater streams of western North America. Past research has primarily examined short-term effects of these disturbances; less is known about longer-term impacts. We investigated wildfire effects on the invertebrate prey base for drift-feeding rainbow trout (Oncorhynchus mykiss, Walbaum) in Idaho headwater streams a dec...

Gut-associated lymphocytes were described in fish, but their involvement in immune responses is still unknown. In rainbow trout, intraepithelial lymphocytes (IELs) are scattered between gut epithelial cells, but neither Peyer's patches nor mesenteric lymph nodes were identified. Rainbow trout IELs contain mainly T cells, because they expressed transcripts of T cell marker homologs of CD8, CD4, ...

We sampled 34 native rainbow trout (Oncorhynchus mykiss) populations over a wide geographic area of British Columbia to determine whether variation in morphology is related to differences in habitat or fish community characteristics experienced by a population. After correcting for differences in body size, the most dramatic differences occurred in external characteristics between streamand lak...

When nonnative species become established within new communities, competition may play a role in determining the persistence of ecologically similar native species. In western North America, many native cutthroat trout (Oncorhynchus clarkii) populations have been replaced by nonnative rainbow trout (Oncorhynchus mykiss). Superior competitive ability of rainbow trout and cutthroat–rainbow trout ...

Myxobolus cerebralis caused severe declines in rainbow trout populations across Colorado following its introduction in the 1980s. One promising approach for the recovery of Colorado's rainbow trout populations has been the production of rainbow trout that are genetically resistant to the parasite. We introduced one of these resistant crosses, known as the GR×CRR (cross between the German Rainbo...