Effects of different ligands on the bioaccumulation and subsequent depuration of dietary Cu and Zn in juvenile rainbow trout (Oncorhynchus mykiss)

2006 ◽  
Vol 63 (2) ◽  
pp. 412-422 ◽  
Author(s):  
Victoria A Kjoss ◽  
Chris M Wood ◽  
D Gordon McDonald
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Metal Accumulation ◽  
Whole Body ◽  
Control Fish ◽  
Dietary Copper ◽  
Juvenile Rainbow Trout ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Control Food ◽  
Cu And Zn

The effects of different ligands on the bioavailability of dietary copper (Cu) and zinc (Zn) to fish have not been thoroughly investigated. We therefore exposed juvenile rainbow trout (Oncorhynchus mykiss; ~200 mg body weight) to control food or to food supplemented with different Cu (~400 µg·g–1 food) or Zn (~1000 µg·g–1 food) compounds. Tissue metal accumulation was compared among groups. Fish fed CuO showed no differences in tissue Cu concentrations relative to control fish, suggesting that Cu was not readily available for uptake in this form. In contrast, Cu in the form of CuSO4, Cu-proteinate, or Cu-lysine was much more available for uptake, resulting in substantial increases in liver, gut tissue, and whole-body Cu concentrations during the loading phase and decreases during depuration, although liver and whole-body levels remained elevated after 2 weeks. We found no differences in tissue Cu accumulation among these three complexes. There were no effects on growth. For Zn, we found no differences among any of the treatments, including controls, in Zn accumulation or growth. Overall, there was homeostasis of whole-body and tissue-specific Zn concentrations despite the large differences in dietary Zn loads.

Conspecific skin extracts elicit antipredator responses in juvenile rainbow trout (Oncorhynchus mykiss)

1997 ◽  
Vol 75 (11) ◽  
pp. 1916-1922 ◽  
Author(s):  
Grant E. Brown ◽  
R. Jan F. Smith
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Whole Body ◽  
Antipredator Behaviour ◽  
Skin Extract ◽  
Distilled Water ◽  
Juvenile Rainbow Trout ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Antipredator Responses ◽  
Body Extract

We investigated, under laboratory conditions, the presence of chemical alarm signals in juvenile rainbow trout (Oncorhynchus mykiss). In an initial experiment, we exposed trout to a whole-body extract from conspecifics or a distilled-water control. When exposed to whole-body extract, trout significantly (i) decreased time spent swimming, (ii) increased time taken to resume foraging, and (iii) decreased the number of food items eaten. These data indicate a significant chemically mediated antipredator response. A second experiment was conducted to determine (i) if this is a generalized response to injured fish or a specific response to injured conspecifics, and (ii) if the chemical signal is localized in the skin. We exposed juvenile trout to one of three chemical stimuli: (1) trout skin extract, (2) trout body extract, or (3) swordtail (Xiphophorus helleri) skin extract. Significant antipredator responses were observed in trout exposed to conspecific skin extract, but responses of those exposed to conspecific body extract or swordtail skin extract did not differ from those of distilled-water controls. These data strongly suggest that juvenile rainbow trout possess a chemical alarm signal, localized in the skin, that elicits antipredator behaviour when detected.by conspecifics.

Effects of Intermittent Chloramine-T Exposure on Growth, Serum Biochemistry, and Fin Condition of Juvenile Rainbow Trout (Oncorhynchus mykiss)

1994 ◽  
Vol 51 (8) ◽  
pp. 1728-1736 ◽  
Author(s):  
Mark D. Powell ◽  
David J. Speare ◽  
Neil MacNair
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Skin Diseases ◽  
Growth Parameters ◽  
Serum Biochemistry ◽  
Control Fish ◽  
Plasma Sodium ◽  
Juvenile Rainbow Trout ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Chloramine T

Chloramine-T is a commonly used therapeutic agent for the treatment of bacterial gill and skin diseases in the intensive aquaculture of salmonids; however, little is known about its effects on healthy fish. Juvenile rainbow trout (Oncorhynchus mykiss) were exposed weekly to 5, 10, and 20 mg active chloramine-T ingredient∙L−1 in a 20-tank replicate flow-through facility. Control fish were treated with tank water only. Growth parameters and haematocrits were taken twice weekly and serum biochemistry was measured on termination of the experiment. Absolute growth rates were suppressed but only statistically significantly in fish treated with 20 mg chloramine-T∙L−1 compared with controls. Fish exposed to 10 and 20 mg chloramine-T∙L−1 showed significant predisposition to an erosive dermatitis of the caudal fin which appeared to be caused by opportunistic pathogens of the genus Pseudomonas spp. and Flavobacter spp. Haematocrits decreased in controls and ail treatments. A significant concentration-dependent decrease in plasma sodium and chloride was observed. Plasma glucose levels did not vary and were similar to those reported for unstressed trout. We recommend that care be taken when using chloramine-T prophylactically and that concentrations of less than 10 mg∙L−1 be used.

Metabolic Costs and Physiological Consequences of Acclimation to Aluminum in Juvenile Rainbow Trout (Oncorhynchus mykiss). 1: Acclimation Specificity, Resting Physiology, Feeding, and Growth

1994 ◽  
Vol 51 (3) ◽  
pp. 527-535 ◽  
Author(s):  
Rod W. Wilson ◽  
Harold L. Bergman ◽  
Chris M. Wood
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Soft Water ◽  
Negligible Effect ◽  
Whole Body ◽  
Rapid Loss ◽  
Juvenile Rainbow Trout ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Metabolic Costs ◽  
Pronounced Reduction

Juvenile rainbow trout (Oncorhynchus mykiss, 5–13 g) became acclimated (i.e., increased their resistance to lethal Al levels, 162 μg∙L−1, pH 5.2) after only 5 d when exposed to sublethal AS (38 μg∙L−1) in acidified soft water (Na+ = 85, Ca2+ = 28 μEq∙L−1, pH 5.2). Acclimation was associated with reduced ionoregulatory and respiratory disturbances during lethal Al challenge and was maintained for at least 34 d. Acclimation was relatively specific to Al because no consistently improved resistance to lethal Cu (32 μg∙L−1, pH 5.2) was observed. Exposure to sublethal acid alone (pH 5.2) did not result in acclimation to lethal [H+] (pH 4.0) and caused a pronounced reduction in whole-body Na+ and Cl−. Sublethal acid + Al resulted in a more rapid loss of ions than sublethal acid alone over the first 10 d, but both groups subsequently recovered ionoregulatory status after 34 d. Exposure to sublethal acid alone had a negligible effect on feeding or growth. However, growth was impaired by 29% in Al-exposed trout, primarily the result of reduced appetite during the first 10 d. Decreased growth must be considered one of the costs of acclimation during chronic sublethal exposure to Al.

Waterborne vs. dietary copper uptake in rainbow trout and the effects of previous waterborne copper exposure

2002 ◽  
Vol 283 (1) ◽  
pp. R69-R78 ◽  
Author(s):  
Collins Kamunde ◽  
Cheryl Clayton ◽  
Chris M. Wood
Keyword(s):  
Rainbow Trout ◽  
High Capacity ◽  
Hard Water ◽  
Whole Body ◽  
Control Fish ◽  
Dietary Copper ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Uptake Rates ◽  
Normal Metabolism ◽  
Cu Homeostasis

Juvenile rainbow trout ( Oncorhynchus mykiss) were exposed to waterborne Cu (22 μg/l) in moderately hard water for up to 28 days. Relative to control fish kept at background Cu levels (2 μg/l), Cu-preexposed fish displayed decreased uptake rates of waterborne Cu via the gills but not of dietary Cu via the gut during 48-h exposures to64Cu-radiolabeled water and diet, respectively. At normal dietary and waterborne Cu levels, the uptake rates of dietary Cu into the whole body without the gut were 0.40–0.90 ng · g−1 · h−1, >10-fold higher than uptake rates of waterborne Cu into the whole body without the gills, which were 0.02–0.07 ng · g−1 · h−1. Previously Cu-exposed fish showed decreased new Cu accumulation in the gills, liver, and carcass during waterborne 64Cu exposures and in the liver during dietary 64Cu exposures. A 3-h gill Cu-binding assay showed downregulation of the putative high-affinity, low-capacity Cu transporters and upregulation of the low-affinity, high-capacity Cu transporters at the gills in Cu-preexposed fish. Exchangeable Cu pools in all the tissues were higher during dietary than during waterborne 64Cu exposures, and previous Cu exposure reduced waterborne exchangeable Cu pools in gill, liver, and carcass. Overall, these results suggest a quantitatively greater role for the dietary than for the waterborne route of Cu uptake, a key role for the gill in Cu homeostasis, and important roles for the liver and gut in the normal metabolism of Cu in fish.

Copper metabolism and gut morphology in rainbow trout (Oncorhynchus mykiss) during chronic sublethal dietary copper exposure

2001 ◽  
Vol 58 (2) ◽  
pp. 293-305 ◽  
Author(s):  
Collins N Kamunde ◽  
Martin Grosell ◽  
John NA Lott ◽  
Chris M Wood
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Granule Cells ◽  
Copper Metabolism ◽  
Exposure Period ◽  
Whole Body ◽  
Electron Microscopic ◽  
Dietary Copper ◽  
Cu Content ◽  
Rainbow Trout Oncorhynchus Mykiss

Juvenile rainbow trout (Oncorhynchus mykiss) were exposed to 11 (control), 300 (medium), and 1000 µg Cu·g–1 (high) (as CuSO4·5H2O) in the diet for 28 days at a daily ration of 4% wet body weight, with a background waterborne Cu concentration of 3 µg·L–1. There was no effect of dietary Cu on growth, condition factor, or food conversion efficiency. Whole-body Cu content increased continuously over the exposure period in all groups and was twofold and fourfold higher than controls at day 28 for the medium- and high-Cu diets, respectively. Copper accumulated mainly in liver and gut tissue, with the latter stabilizing by day 14. Accumulation also occurred in gill, kidney, and carcass. Plasma Cu concentration was not different from the controls whereas Cu in bile was greatly elevated, an indication of increased hepatobiliary excretion. Dietary Cu pre-exposure decreased the uptake of waterborne Cu across the gills, providing the first evidence of homeostatic interaction between the two routes of uptake. Electron microscopic observations of the midintestine revealed numerous mitochondria, lysosomes, lamellated bodies, and extensive lamellar processes in the enterocytes. Apoptosis, mitosis, and eosinophilic granule cells were more apparent in Cu-exposed fish.

scholarly journals Graded Incorporation of Defatted Yellow Mealworm (Tenebrio molitor) in Rainbow Trout (Oncorhynchus mykiss) Diet Improves Growth Performance and Nutrient Retention

Animals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 187 ◽  
Author(s):  
Paulo Rema ◽  
Subramanian Saravanan ◽  
Benjamin Armenjon ◽  
Constant Motte ◽  
Jorge Dias
Keyword(s):  
Body Composition ◽  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Growth Performance ◽  
Tenebrio Molitor ◽  
Nutrient Digestibility ◽  
Protein Meal ◽  
Yellow Mealworm ◽  
Juvenile Rainbow Trout ◽  
Rainbow Trout Oncorhynchus Mykiss

Insects are emerging as a sustainable alternative to fishmeal and fish oil in aquafeeds. This study assessed the effect of graded incorporation levels of defatted yellow mealworm (Tenebrio molitor) protein meal on juvenile rainbow trout (Oncorhynchus mykiss) growth performance, body composition, and apparent nutrient digestibility. The trial comprised five dietary treatments: control diet with 25% fishmeal, and four experimental diets with yellow mealworm protein meal at 5%, 7.5%, 15%, or 25%, which corresponded to a fishmeal replacement of 20%, 30%, 60%, or 100%, respectively. After 90 days, the graded incorporation of insect protein meal led to a significant stepwise increase in final body weight, and a significant improvement of specific growth rate, feed conversion ratio, and protein efficiency ratio compared to the control treatment. Regardless of the incorporation level, the insect protein meal had no effects on fish whole-body composition and apparent digestibility coefficients of dry matter, protein, fat, phosphorus, and energy. Protein, phosphorus, and energy retention significantly increased in fish fed the diets with an insect protein meal. In conclusion, the yellow mealworm protein meal could effectively replace 100% of fishmeal in the diet of juvenile rainbow trout with positive effects on its overall zootechnical performance.

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