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...

—Outlet barriers in stocked lakes of the Adirondack Mountains were used to test the hypothesis that preventing fall emigration by adult brook trout Salvelinus fontinalis would increase trap-net and angling catch rates as well as the number of large trophy fish. Outlet barriers were maintained during the fall spawning season for 6 years on one lake and 10 years on another lake. We compared preba...

—Irrigation canals can be a major source of mortality for fish in the Rocky Mountain region. Our study looked at how fish were affected by the irrigation canal system in the Smiths Fork, a tributary to the Bear River in western Wyoming. There are two native species of conservation concern in the Smiths Fork drainage: Bonneville cutthroat trout Oncorhynchus clarkii utah and northern leatherside ...

Portable antennas have become an increasingly common technique for tracking fish marked with passive integrated transponder (PIT) tags. We used logistic regression to evaluate how species, fish length, and physical habitat characteristics influence portable antenna detection efficiency in stream-dwelling brown trout (Salmo trutta), bull trout (Salvelinus confluentus), and redband trout (Oncorhy...

The widespread use of plastic products in our modern life represents a serious threat to aquatic environments and wild animals that are exposed waste. Although microplastics (MPs) have been reported fish from several freshwater around the world, mountain little studied so far. occurrence MPs was assessed gastrointestinal tracts (GITs) non-native (rainbow trout Oncorhynchus mykiss brown Salmo tr...

We have isolated and sequenced a clone from a rainbow trout (Salmo gairdneri) genomic library that carries a gene encoding a fish growth hormone (GH). This gene spans a region of approximately equal to 4 kilobases, nearly twice that of mammalian GH genes. The trout GH gene is comprised of six exons, in contrast with five exons in mammals. The additional intron in the fish gene interrupts transl...

—Fish movement during sampling may negatively bias sample data and population estimates. We evaluated the short-term movements of stream-dwelling salmonids by recapture of marked individuals during day and night snorkeling and backpack electrofishing. Bull trout Salvelinus confluentus and rainbow trout Oncorhynchus mykiss were captured in sufficient numbers to evaluate instream movements and th...

Accurate knowledge of food webs is important in understanding aquatic ecology. One common way to determine the food web structure of an aquatic ecosystem is to perform stomach content analysis. Gastric lavage has developed into the preferred method for collecting dietary data from live fish. The objective of this study was to determine the efficiency of gastric lavage for age-0 brook trout Salv...

The breakdown products of adenosine triphosphate (ATP), adenosine diphosphate (ADP), adenosine monophosphate (AMP), inosine monophosphate (IMP), inosine (Ino) and hypoxanthine (Hx) of some fish species and heated fish products were determined by high-performance liquid chromatography (HPLC) and rapid paper strip method. The K value, calculated from ATP degradation products, the percent of the s...

Chaetoceros concavicornis and C. convolutus are harmful diatom species which commonly occur in many temperate coastal marine waters and which can cause finfish mortalities when present at concentrations as low as 5 cells ml-' of seawater. Death of finfish, including salmonids, by these harmful Chaetocerosspp. has been suggested to be caused by: (1) microbial infections of damaged gill tissue; (...