the objective of this study was to compare growth performance and feed conversion ratios of rainbow trout (oncorhynchus mykiss) and brook trout (salvelinus fontinalis) juveniles in monoculture and duo-culture in freshwater and seawater under aquarium conditions. the fish were about 2-months old hatchery-reared brook and rainbow trout with initial weights of 0.934±0.033 (n=360) and 1.014±0.019 (...

Cortisol is a key hormone in the fish stress response with a well-known ability to regulate several physiological functions, including energy metabolism and the immune system. However, data concerning cortisol effects on fish innate immune system using a more controlled increase in cortisol levels isolated from any other stress related signaling is scarce. The present study describes the effect...

  There is a few available information about the effect of anesthetics, specially electroanesthesia on immune parameters in fish. In the present work, two anesthetics, MS222 (50 ppm), clove oil (25 ppm), and electroanesthesia were tested in rainbow trout (Oncorhynchus mykiss) in narcosis stage. The results showed, clove oil and electroanesthesia increase the lysozyme activity 24 h after anesthe...

The aim of our study was to evaluate the effects of chitosan as immune stimulator on some hematological parameters and stress resistance in rainbow trout. Nine hundred rainbow trout (with initial body weight of 25 ± 0.1 g) were obtained from a local farm and acclimated to the laboratory conditions for one week. After that fish were randomly divided into four groups in three replicates. Each gro...

Trichomoniasis is one of the most common urinary-genital tract disease. The causal agent of trichomoniasis is flagellate protozoan called Trichomonas vaginalis. Metronidazole and tinidazole are the drug of choice for treatment. Carcinogenic and embryo-teratogenic effects of the mentioned drugs and resistance to metronidazole has been reported. According to cytotoxic effects of medicinal herbs i...

Much has been written about introduced rainbow trout interbreeding and outcompeting native cutthroat trout. However, the specific mechanisms by which rainbow trout and their hybrids outcompete cutthroat trout have not been thoroughly explored, and most of the published data is limited to lotic ecosystems. Samples of Snake River cutthroat trout (Oncorhynchus clarkii bouvieri), the rainbow-cutthr...

Hybridization between rainbow trout (Oncorhynchus mykiss (Walbaum, 1792)) and westslope cutthroat trout (Oncorhynchus clarkii lewisi (Girard, 1856)) occurs commonly when rainbow trout are introduced into the range of westslope cutthroat trout. Typically, hybridization ismost common inwarmer, lower elevation habitats, butmuch less common in colder, higher elevation habitats. We assessed the tole...

BACKGROUND Estimates of fishing and natural mortality are important for understanding, and ultimately managing, commercial and recreational fisheries. High reward tags with fixed station acoustic telemetry provides a promising approach to monitoring mortality rates in large lake recreational fisheries. Kootenay Lake is a large lake which supports an important recreational fishery for large Bull...

Multiple Hemoglobin Components in Cutthroat and Rainbow Trout Multiple hemoglobin components in fish is a well-documented phenomenon, with cutthroat trout having twelve (Figure 1a) and rainbow trout having nine (Figure 1b) hemoglobin components (Braman et al.1977). A high-resolution starch gel electrophoresis method was developed to resolve eight negatively charged hemoglobin components from bo...