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.

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.

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.

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.

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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