Swimming performance, whole body ions, and gill Al accumulation during acclimation to sublethal aluminium in juvenile rainbow trout (Oncorhynchus mykiss)

1992 ◽  
Vol 10 (2) ◽  
pp. 149-159 ◽  
Author(s):  
Rod W. Wilson ◽  
Chris M. Wood
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Swimming Performance ◽  
Whole Body ◽  
Juvenile Rainbow Trout ◽  
Rainbow Trout Oncorhynchus Mykiss

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.

Individual variation and interrelationships between swimming performance, growth rate, and feeding in juvenile rainbow trout (Oncorhynchus mykiss)

1998 ◽  
Vol 55 (7) ◽  
pp. 1583-1590 ◽  
Author(s):  
T Ryan Gregory ◽  
Chris M Wood
Keyword(s):  
Growth Rate ◽  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Plasma Cortisol ◽  
Positive Relationship ◽  
Swimming Performance ◽  
Individual Performance ◽  
Significant Positive Relationship ◽  
Juvenile Rainbow Trout ◽  
Rainbow Trout Oncorhynchus Mykiss

Variation among individuals in specific growth rate (SGR), feeding, and two measures of swimming performance and their possible interrelationships were investigated in juvenile rainbow trout (Oncorhynchus mykiss) kept in groups on either satiation or half-satiation rations. Maximum sustainable velocity (Ucrit) was measured as an index of aerobic swimming performance and stamina (fatigue time in a fixed-velocity test at 6 body lengths ·s-1) as an index of anaerobic performance. Individual performance in both of these tests was found to be significantly repeatable. Trout fed on half-satiation ration exhibited significantly lower mean values of SGR and body size and higher levels of aggression-related fin damage, but no significant differences in stamina, relative or absolute Ucrit, glycogen content, or plasma cortisol. However, in these fish, there was a significant negative relationship between SGR and relative Ucrit, a significant positive relationship between SGR and stamina, and a significant positive relationship between SGR and total daily meal. None of these relationships were seen in fish fed to satiation. Plasma cortisol and tissue glycogen stores were not related to SGR. These results indicate that under the intensified competition of restricted ration, there are trade-offs between growth, feeding, and different types of swimming performance.

Metabolic Costs and Physiological Consequences of Acclimation to Aluminum in Juvenile Rainbow Trout (Oncorhynchus mykiss). 2: Gill Morphology, Swimming Performance, and Aerobic Scope

1994 ◽  
Vol 51 (3) ◽  
pp. 536-544 ◽  
Author(s):  
Rod W. Wilson ◽  
Harold L. Bergman ◽  
Chris M. Wood
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Surface Area ◽  
Swimming Performance ◽  
Mucous Cell ◽  
Aerobic Scope ◽  
Fourfold Increase ◽  
Juvenile Rainbow Trout ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Oxygen Requirements

Juvenile rainbow trout (Oncorhynchus mykiss, 5–13 g) were chronically exposed to sublethal Al (38 μg∙L−1) in acidified soft water (Na+ = 85, Ca2+ = 28 μEq∙L−1, pH 5.2–5.4) for 36 d. Acclimation (increased resistance to challenge with 162 μg Al∙L−1 Al at pH 5.2) occurred after 5 d and was associated with a fourfold increase in gill mucous cell density and reduction in apparent lamellar surface area; initially elevated blood–water diffusion distances returned to normal after 34 d, but the reduction in apparent surface area persisted. Chronic exposure to acid alone (pH 5.2, same water chemistry) caused no morphometric changes but resulted in persistent impairment of Ucrit (critical aerobic swimming speed) by about 10%. This was due to increased oxygen requirements at subcritical swimming speeds (loading stress) and was alleviated when trout were swum at pH 6.5 (zero Al) on day 36. In trout preexposed to sublethal Al, Ucrit was chronically impaired by approximately 16% due to loading stresses and reduction in the maximum rate of oxygen uptake, Mo2max (limiting stress); Ucrit and Mo2max remained depressed even when fish were swum at pH 6.5 (zero Al). Reduced gill area compromises the aerobic scope for activity but may be an unavoidable cost of acclimation to Al.

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.

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.

Sublethal Effects of Tetrachloroguaiacol on Juvenile Rainbow Trout, Oncorhynchus mykiss, following Acute and Chronic Exposure

1994 ◽  
Vol 51 (9) ◽  
pp. 1967-1974 ◽  
Author(s):  
J. A. Johansen ◽  
C. J. Kennedy ◽  
R. M. Sweeting ◽  
A. P. Farrell ◽  
B. A. McKeown
Keyword(s):  
Disease Resistance ◽  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Chronic Exposure ◽  
Plasma Cortisol ◽  
Sublethal Effects ◽  
Swimming Performance ◽  
Juvenile Rainbow Trout ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Acute And Chronic Exposure

Following either a 24-h (acute) or 25-d (chronic) exposure to tetrachloroguaiacol (TeCG), a component of bleached kraft mill effluent (BKME), juvenile rainbow trout, Oncorhynchus mykiss, were examined for effects on several biochemical parameters, swimming performance, and disease resistance. Acute exposure resulted in increased levels of plasma cortisol and lactate and reductions in liver glycogen and protein, spleen somatic index, leucocrit, hemoglobin, swimming performance, and disease resistance. Chronic exposure resulted in most parameters remaining at control levels with the exception of leucocrit which was elevated, plasma cortisol which decreased, and disease resistance which was impaired. These findings correlate well with a previously proposed classic stress response for mammals and are generally consistent with studies in which fish were exposed to whole BKME. The 96-h LC50 for juvenile rainbow trout exposed to TeCG was estimated at 0.37 mg∙L−1.

Interactions between individual feeding behaviour, growth, and swimming performance in juvenile rainbow trout (Oncorhynchus mykiss) fed different rations

1999 ◽  
Vol 56 (3) ◽  
pp. 479-486 ◽  
Author(s):  
T Ryan Gregory ◽  
Chris M Wood
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Food Consumption ◽  
Swimming Performance ◽  
Negative Relationship ◽  
Daily Group ◽  
Juvenile Rainbow Trout ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Significant Negative Relationship ◽  
Dry Food

Aerobic swimming performance (critical swimming speed, Ucrit), food consumption per meal (by X-ray radiography), specific growth rate (SGR), haematocrit, and fin condition were monitored in individual juvenile rainbow trout (Oncorhynchus mykiss). The fish were held in groups over a 9-week period and fed daily group rations (dry food) of 2.0, 1.5, 1.0, and 0.5% wet body mass (BM)·day-1. SGR declined and competition increased at lower ration levels, as reflected by greater fin damage, reduced haematocrits and condition factors, and, at 0.5% BM·day-1, a substantial increase in the coefficient of variation among individual meals. Absolute Ucrit also declined at lower ration levels. However, there was no relationship between Ucrit and haematocrit, fin damage, or condition factor in any of the ration groups. A negative correlation was found between Ucrit and SGR in individual trout fed a group ration of 2.0% BM·day-1, but a positive correlation was seen at 0.5% BM·day-1 and no relationship at 1.0 and 1.5% BM·day-1. There was a positive relationship between individual SGR and food consumption only among fish fed a ration of 2.0% BM·day-1. A significant negative relationship between Ucrit and individual food consumption was also found among fish in this ration group.

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