Selenium effect levels for selected representative/surrogate species

William Beckon

U.S. Fish and Wildlife Service

July 31, 2009
Table 1. Summary: Selenium effect levels for selected representative/surrogate species

Species 0% 5% 10% 0% 5% 10% Effect

Exposure 

duration (days) Form of selenium Model Data source

Mallard duck 2.30 4.36 5.29 2.77 5.86 7.73 hatchability >40 (parental) seleno-DL-methionine Beckon et al . 2008 Heinz et al . 1989

White sturgeon na 7.03 8.13 larval edema and skeletal 

defects

up to 6 months selenized yeast log-logistic Linville 2006

 adult na 25.5 32.5 assimilation 6 months selenized yeast power Linville 2006

 juvenile na 0.95 1.57 assimilation 56 seleno-L-methionine power Tashjian et al 2006

Chinook salmon 1.54 2.25 2.67 1.01 1.53 1.84 mortality 90 assimilated or selenoDL-methionineBrain and Cousens 1989 Hamilton et al. 1990

Rainbow trout 2.41 4.22 5.04 1.27 1.89 2.19 reduction in growth 140 sodium selenite Beckon et al . 2008 Hilton et al . 1980

0.31 1.01 1.56 assimilation 90 seleno-L-methionine power Vidal et al . 2005

Se in diet

Se in target 

species (whole 

body or egg)

Concentration of selenium (μg/g 

dry wt.) corresponding to effect 

level:
Mallard (Anas platyrhynchos)

Tissue

0

0.2

0.4

0.6

0.8

0.1 1 10 100

Selenium concentration in eggs (μg/g 

dry weight)

Hatchability (proportion of 

fertile eggs hatched)

reduction

 in hatch due to

 selenium

EC10 = 7.73 μg/g 

0%

5%

10%

EC05 = 5.86 μg/g 

EC00 = 2.77 μg/g 

Figure 1. Relationship between hatchability of fertile eggs and concentration of selenium in one egg from 

each clutch laid by mallard ducks after exposure to dietary selenium in the form of seleno-DL-methionine

(Heinz et al. 1989; see Table 2). The biphasic model is that of Beckon et al. (2008). 

Table 2. Selenium concentration in mallard eggs (average for each treatment, one egg per hen) and 

proportion of fertile eggs hatched (average for each treatment) after exposure of hens to dietary selenium 

in the form of seleno-DL-methionine. Data are from Tables 2 and 4 in Heinz et al. (1989). Concentrations 

of selenium, reported on wet-weight basis, were converted to dry weight assuming 70% moisture, in 

accordance with Ohlendorf (2003).

 x y

Selenium 

concentration 

in eggs (ug/g 

dry weight)

Hatchability 

(proportion 

of eggs 

hatched)

0.59 0.596

2.74 0.707

5.28 0.6

11.2 0.534

36.3 0.369

59.4 0.022
The analysis was that presented in Beckon et al. 2008 Supporting Information.

Diet

0

0.5

1

0.1 1 10 100

Selenium in diet (μg/g dry wt. calculated)

Hatchability (proportion of fertile 

eggs hatched)

reduction

 in hatch due to

 selenium

EC10 = 5.29 μg/g 

0%

5%

10%

EC05 = 4.36 μg/g 

EC00 = 2.30 μg/g 

Figure 2. Relationship between hatchability of fertile eggs and concentration of selenium in the diet of the 

parent female mallard duck after exposure to dietary selenium in the form of seleno-DL-methionine

(Heinz et al. 1989). The biphasic model is that of Beckon et al. (2008).
Table 3. Hatchability of fertile eggs and concentration of selenium in the diet and in one egg from each 

female mallard duck after exposure to dietary selenium in the form of seleno-DL-methionine. Data are 

from Gary Heinz (pers. com) with calculations (in red) using data in Heinz et al. (1989) with control diet 

data from Heinz and Fitzgerald (1993). Dietary concentration on a dry weight basis was calculated from 

reported nominal wet weight concentration converted to dry weight based on percent moisture reported as 

about 10%, added to the control diet wet concentration (geometric mean of 0.33, 0.41, and <0.2 [treated as 

0.1] μg/g wet weight) reported in Heinz and Fitzgerald (1993) converted to dry weight based on 10% 

moisture. 

x y

Pen 

no.

Dietary

Se 

nominal 

wet wt.

Dietary 

Se 

calculated 

dry wt. 

incl. 

control

Egg 

Se 

(wet 

wt)

Egg Se 

(dry wt 

calculated 

using 

70% 

moisture)

% 

hatch

Hatchability 

(proportion 

hatched)

1 0 0.26 86.7 0.867

3 0 0.26 69.2 0.692

8 0 0.26 20 0.2

10 0 0.26 53.3 0.533

18 0 0.26 80 0.8

23 0 0.26 86.7 0.867

24 0 0.26 86.7 0.867

35 0 0.26 60 0.6

43 0 0.26 20 0.2

44 0 0.26 20 0.2

48 0 0.26 100 1

55 0 0.26 60 0.6

59 0 0.26 60 0.6

61 0 0.26 50 0.5

72 0 0.26 64.3 0.643

74 0 0.26 75 0.75

75 0 0.26 46.2 0.462

85 0 0.26 35.7 0.357

91 0 0.26 46.7 0.467

92 0 0.26 66.7 0.667

93 0 0.26 40 0.4

98 0 0.26 93.3 0.933

101 0 0.26 80 0.8

103 0 0.26 50 0.5

105 0 0.26 80 0.8

106 0 0.26 100 1

111 0 0.26 20 0.2

5 0 0.26 0.11 0.37 41.7 0.417

37 0 0.26 0.16 0.53 60 0.6

67 0 0.26 0.18 0.60 18.2 0.182

53 0 0.26 0.21 0.70 36.4 0.364

15 0 0.26 0.23 0.77 26.7 0.267

49 1 1.38 0.36 1.20 100 1

13 1 1.38 0.58 1.93 73.3 0.733

88 1 1.38 0.60 2.00 71.4 0.714
109

1 1.38 0.67 2.23 46.2 0.462

1151 1.38 0.71 2.37 1001

401 1.38 0.73 2.43 20 0.2

1141 1.38 0.77 2.57 73.3 0.733

621 1.38 0.79 2.63 71.4 0.714

111 1.38 0.82 2.73 78.6 0.786

141 1.38 0.87 2.90 21.4 0.214

161 1.38 0.90 3.00 93.3 0.933

221 1.38 1.10 3.67 1001

341 1.38 1.10 3.67 26.7 0.267

252 2.49 1.10 3.67 33.3 0.333

702 2.49 1.10 3.67 60 0.6

321 1.38 1.20 4.00 1001

381 1.38 1.20 4.0000

802 2.49 1.20 4.00 46.7 0.467

902 2.49 1.20 4.00 66.7 0.667

582 2.49 1.30 4.33 46.7 0.467

842 2.49 1.40 4.67 41.7 0.417

822 2.49 1.50 5.00 61.5 0.615

122 2.49 1.60 5.3300

312 2.49 1.60 5.33 80 0.8

512 2.49 1.60 5.33 78.6 0.786

262 2.49 1.80 6.00 80 0.8

782 2.49 1.90 6.33 61.5 0.615

862 2.49 1.90 6.33 60 0.6

422 2.49 2.00 6.67 1001

172 2.49 2.10 7.00 76.9 0.769

974 4.71 2.20 7.3300

734 4.71 2.30 7.67 20 0.2

414 4.71 2.70 9.00 53.3 0.533

794 4.71 2.70 9.00 35.7 0.357

1084 4.71 3.10 10.33 40 0.4

44 4.71 3.30 11.00 73.3 0.733

954 4.71 3.30 11.00 90.9 0.909

834 4.71 3.40 11.3393.3 0.933

334 4.71 3.50 11.67 46.7 0.467

814 4.71 3.60 12.00 61.5 0.615

564 4.71 3.90 13.00 57.1 0.571

644 4.71 4.00 13.33 73.3 0.733

214 4.71 4.10 13.67 66.7 0.667

364 4.71 4.30 14.33 66.7 0.667

684 4.71 4.30 14.33 35.7 0.357

68 9.15 4.90 16.33 42.8 0.428

78 9.15 6.20 20.67 73.3 0.733

1138 9.15 6.70 22.33 50 0.5

57 16 18.04 8.50 28.33 26.7 0.267

1128 9.15 9.30 31.00 60 0.6

278 9.15 10.00 33.33 73.3 0.733

478 9.15 11.00 36.67 13.3 0.133
71 8 9.15 11.00 36.67 0 0

87 8 9.15 11.00 36.67 88.9 0.889

89 8 9.15 11.00 36.67 100 1

45 8 9.15 12.00 40.00 0 0

9 8 9.15 13.00 43.33 53.3 0.533

20 8 9.15 13.00 43.33 0 0

69 8 9.15 13.00 43.33 0 0

77 8 9.15 13.00 43.33 26.7 0.267

100 16 18.04 13.00 43.33 26.7 0.267

104 16 18.04 13.00 43.33 0 0

52 8 9.15 14.00 46.67 53.3 0.533

65 16 18.04 18.00 60.00 13.3 0.133

19 16 18.04 19.00 63.33 0 0

46 16 18.04 21.00 70.00 0 0

96 16 18.04 23.00 76.67 0 0

110 16 18.04 23.00 76.67 0 0

63 16 18.04 25.00 83.33 0 0

nls(start=list(eUp=0.0452,bUp=0.1417,eDn=10.0533,bDn=-2.659),

control=list(tol=.06,maxiter=50,minFactor=1/1024,printEval=FALSE,warnOnly 

=FALSE),data = SeMallardHeinzRawDiet, trace=TRUE, formula = 

y~1/((1+(eUp/x)^bUp)*(1+(eDn/x)^bDn)))

Parameters:

 Estimate Std. Error t value Pr(>|t|) 

eUp 0.0452 0.1402 0.322 0.7478 

bUp 0.1417 0.1665 0.851 0.3968 

eDn 10.0533 2.0246 4.966 2.93e-06 ***

bDn -2.6590 1.2940 -2.055 0.0426 * 

---

Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1 

Residual standard error: 0.2708 on 97 degrees of freedom

Number of iterations to convergence: 0 (manually fitted)

Achieved convergence tolerance: 0.05054
White sturgeon (Acipenser transmontanus)

Note: unpublished data from UC Davis indicate that green sturgeon are more sensitive 

to selenium than white sturgeon.

Tissue

0

10

20

30

40

1 10 100

Selenium concentration in maternal 

muscle (μg/g dry wt.)

Incidence of edema or skeletal 

deformities in larvae (percent)

EC10 = 11.53 μg/g 

White sturgeon

Linville 2006

regression:

 y=100/(1+(18.85/x)4.47)

EC05 = 9.75 μg/g

EC00 = undefined

Figure 3. The relationship between selenium in the muscle tissue of adult female white sturgeon and the 

occurrence of edema and/or skeletal deformities in the larvae (at the end of yolk sac absorption) that hatch 

from their eggs. The data are from Table 3-18 in Linville 2006 (Table 4 below).

Table 4. Selenium in the diet and muscle tissue of adult female white sturgeon and the occurrence of 

edema and/or skeletal deformities in the larvae (at the end of yolk sac absorption) that hatch from their 

eggs (from Table 3-18 in Linville 2006). Corresponding selenium in diet and whole-body (in red) were 

calculated using data from Tables 2 and 3 in Tashjian et al. (2006).

diet y

Selenium 

concentration 

in maternal 

diet (μg/g 

dry wt.)

Selenium 

concentration 

in maternal 

muscle (μg/g 

dry wt.)

Selenium 

concentration 

in diet (μg/g 

dry wt.)

Selenium 

concentration 

in whole 

body (μg/g 

dry wt.)

Incidence 

of edema 

or skeletal 

deformities 

in larvae 

(percent)

1.42 1.28 0.0020 1.211 0

1.42 1.22 0.0017 1.161 0

1.42 1.48 0.0031 1.373 0

34.04 9.93 0.9990 7.147 0

34.04 11.1 1.4007 7.872 13.33

34.04 15.3 3.7082 10.396 27.78
y~100/(1+(e/x)^(b))

e=20,b=1

Formula: y ~ 100/(1 + (e/x)^(b))

Parameters:

 Value Std. Error t value 

e 18.85050 1.51369 12.45330

b 4.46565 1.18170 3.77899

Residual standard error: 3.60266 on 4 degrees of freedom

7 8 9 10 20 30 40 50 60

Selenium in muscle (ug/g dry wt.)

10

4

5

6

7

8

9

20

30

40

Selenium in whole body (ug/g dry wt.)

regression:

y=10^(-0.009917+0.8667*log10(x))

Figure 4. Relationship between muscle and whole-body concentrations of selenium in young white 

sturgeon (initially weighing about 30 g) exposed for 56 days to dietary selenium in the form of seleno-Lmethionine. Data are from Tables 2 and 3 in Tashjian et al. 2006.
Table 5. Diet, muscle, and whole body concentrations of selenium in young white sturgeon (initially 

weighing about 30 g) exposed for 56 days to dietary selenium in the form of seleno-L-methionine. Data 

are from Tables 2 and 3 in Tashjian et al. 2006.

 diet musc WB

Selenium 

in diet 

(μg/g 

evidently 

essentially 

dry)

Selenium 

in 

muscle 

(μg/g dry 

wt.)

Selenium 

in 

sturgeon 

(μg/g 

whole 

body dry 

wt.) 

0.4 8.2 5.2

9.6 17.2 11.8

20.5 22.9 14.7

41.7 36.8 22.5

89.8 52.9 34.4

191.1 54.8 27.5

0

10

20

30

40

1 10 100

Selenium concentration in maternal 

whole body (μg/g dry wt.)

Incidence of edema or skeletal 

deformities in larvae (percent)

EC10 = 8.13 μg/g

White sturgeon

Linville 2006

Tashjian et al . 2006

regression:

 y=100/(1+(12.46/x)5.149)

EC05 = 7.03 μg/g

EC00 = undefined

Figure 5. The relationship between selenium in the whole bodies of adult female white sturgeon and the 

occurrence of edema and/or skeletal deformities in the larvae (at the end of yolk sac absorption) that hatch 

from their eggs. The data are from Table 3-18 in Linville 2006, using Tashjian et al. (2006) data (Figure 4 

above) to convert muscle selenium concentrations to whole body selenium concentrations.

nls(formula = y~100/(1+(e/diet)^b),

 data = WhiteSturgeonEffects,

 start = list(e=5,b=1.9),trace=TRUE)

Parameters:
 Estimate Std. Error t value Pr(>|t|) 

e 6.9847 1.7016 4.105 0.0148 *

b 1.4719 0.3895 3.779 0.0195 *

---

Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1 

Residual standard error: 3.603 on 4 degrees of freedom

Number of iterations to convergence: 6 

Achieved convergence tolerance: 2.548e-06

Diet (adult)

1

10

100

1 10 100

Selenium concentration in maternal 

diet (μg/g dry wt.)

Selenium concentration in 

maternal muscle (μg/g dry wt.)

White sturgeon

regression:

 logy=0.01594+0.69173*logx

Figure 6. Relationship between diet and muscle concentrations of selenium in adult white sturgeon 

exposed for six months to dietary selenium in the form of selenized yeast. Data are from Table 1-3 in 

Linville (2006). (Figure 4 above)

lm(formula = log10(musc) ~ log10(diet), data = WhiteSturgeonEffects)

Residuals:

 1 2 3 4 5 6 

-0.01407 -0.03492 0.04898 -0.07871 -0.03033 0.10904 

Coefficients:

 Estimate Std. Error t value Pr(>|t|) 

(Intercept) 0.01594 0.04866 0.327 0.759729 

log10(diet) 0.69173 0.04470 15.475 0.000102 ***
---

Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1 

Residual standard error: 0.07553 on 4 degrees of freedom

Multiple R-squared: 0.9836, Adjusted R-squared: 0.9795 

F-statistic: 239.5 on 1 and 4 DF, p-value: 0.0001018

Diet (juvenile)

0.4 0.6 1 2 3 4 5 67810 20 30 40 60 100 200

Selenium in diet (ug/g dry wt.)

10

5

6

7

8

9

20

30

40

50

60

Selenium in muscle (ug/g dry wt.)

regression:

log10y=0.99709+0.32961*log10x

Figure 7. Relationship between diet and muscle concentrations of selenium in young white sturgeon 

(initially weighing about 30 g) exposed for 56 days to dietary selenium in the form of seleno-L-methionine. 

Data are from Table 3 in Tashjian et al. 2006.

Call:

lm(formula = log10(musc) ~ log10(diet), data = WhiteSturgeonTTF)

Residuals:

 1 2 3 4 5 6 

0.04788 -0.08533 -0.06962 0.03475 0.08255 -0.01023 

Coefficients:

 Estimate Std. Error t value Pr(>|t|) 

(Intercept) 0.99709 0.05515 18.081 5.5e-05 ***

log10(diet) 0.32961 0.03549 9.288 0.000748 ***

---

Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1 
Residual standard error: 0.07508 on 4 degrees of freedom

Multiple R-squared: 0.9557, Adjusted R-squared: 0.9446 

F-statistic: 86.26 on 1 and 4 DF, p-value: 0.0007476

0

10

20

30

40

0.001 0.01 0.1 1 10

Selenium concentration in diet (μg/g dry 

wt. calculated)

Incidence of edema or skeletal 

deformities in larvae (percent)

EC10 = 1.57 μg/g 

White sturgeon

Linville 2006

Tashjian et al . 2006

regression:

 y=100/(1+(6.985/x)1.472)

EC05 = 0.945 μg/g

EC00 = undefined

Figure 8. The relationship between selenium in the diets of white sturgeon and the occurrence of edema 

and/or skeletal deformities in the larvae (at the end of yolk sac absorption) that hatch from their eggs. 

The data (Table 4 above) are from Table 3-18 in Linville 2006, using Tashjian et al. (2006) data (Figure 7

above) to convert muscle selenium concentrations to dietary selenium concentrations.

nls(formula = y~100/(1+(e/diet)^b),

 data = WhiteSturgeonEffects,

 start = list(e=5,b=1.9),trace=TRUE)

Parameters:

 Estimate Std. Error t value Pr(>|t|) 

e 6.9847 1.7016 4.105 0.0148 *

b 1.4719 0.3895 3.779 0.0195 *

---

Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1 

Residual standard error: 3.603 on 4 degrees of freedom

Number of iterations to convergence: 6 

Achieved convergence tolerance: 2.548e-06
Chinook salmon (Oncorhynchus tshawytscha)

Tissue

0.0

0.2

0.4

0.6

0.8

0.1 1 10 100

Selenium in fish (μg/g whole body dry wt.)

Survival

"control"

SLD fish diet

SeMet-spiked diet

Brain-Cousens model

Atlantic salmon

reduction

 in survival 

 due to Se

EC10 = 1.84 μg/g 

0%

5%

10%

EC05 = 1.53 μg/g 

EC00 = 1.02 μg/g 

Figure 9. Relationship between survival of juvenile Chinook salmon and concentration of selenium in 

their tissues after 90 days exposure to dietary selenium in the form of wild-caught fish (red dots) or selenoDL-methionine (blue dots) (Hamilton et al. 1990). The biphasic model is that of Brain and Cousens (1989). 

Atlantic salmon data from Poston et al. (1976) were not used in the model, but are shown here as 

validation of the generality of the model.
Table 6. Survival of juvenile Chinook salmon and concentration of selenium in their diet and in their 

tissues after 90 days exposure to dietary selenium in the form of wild-caught fish (SLD) or seleno-DLmethionine (SeMet). The data are from Tables 3 and 5 in Hamilton et al. (1990).

diet y

nls(start = list(f=1.7,e=.8,b=-1.67),control= 

list(tol=.001,maxiter=50,minFactor=1/1024,printEval=FALSE,warnOnly 

=FALSE),trace=TRUE,

 data = ChinookSalmon,formula = y~f*x/(1+(e/x)^b))

Parameters:

 Estimate Std. Error t value Pr(>|t|) 

f 1.7143 0.4684 3.66 0.00640 ** 

e 0.7993 0.2103 3.80 0.00524 ** 

b -1.6657 0.0955 -17.44 1.19e-07 ***

---

Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1 

Residual standard error: 0.0531 on 8 degrees of freedom

Number of iterations to convergence: 2 

Achieved convergence tolerance: 0.0001288

Diet 

type

Selenium 

in diet 

(μg/g dry 

wt.)

Selenium 

in fish 

(μg/g 

whole 

body dry 

wt.)

Survival

SLD 3.2 2.7 0.56

SLD 5.3 4 0.447

SLD 6.9 6.5 0.312

SLD 18.2 14.3 0.209

SLD 35.4 33.4 0.182

Control 1 0.8 0.667

SeMet 3.2 1.7 0.725

SeMet 5.3 2.6 0.45

SeMet 6.9 5.4 0.375

SeMet 18.2 10.8 0.224

SeMet 35.4 27.8 0.107
Diet

0.0

0.2

0.4

0.6

0.8

1 10 100

Selenium in diet (μg/g dry wt.)

Survival

"control"

SLD fish diet

SeMet-spiked diet

Brain-Cousens model

reduction

 in survival 

 due to Se

EC10 = 2.67 μg/g 

0%

5%

10%

EC05 = 2.25 μg/g 

EC00 = 1.54 μg/g 

Figure 10. Relationship between concentration of selenium in the diets of juvenile Chinook salmon and

survival and after 90 days exposure to dietary selenium in the form of wild-caught fish (red dots) or 

seleno-DL-methionine (blue dots) (Hamilton et al. 1990). The biphasic model is that of Brain and Cousens

(1989). 

nls(start = list(f=1.7,e=.8,b=-1.67),control= 

list(tol=.001,maxiter=50,minFactor=1/1024,printEval=FALSE,warnOnly 

=FALSE),trace=TRUE,

 data = ChinookSalmon,formula = y~f*diet/(1+(e/diet)^b))

Parameters:

 Estimate Std. Error t value Pr(>|t|) 

f 1.0945 0.2367 4.625 0.00170 ** 

e 1.3180 0.2858 4.611 0.00173 ** 

b -1.7583 0.1148 -15.315 3.28e-07 ***

---

Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1 

Residual standard error: 0.05906 on 8 degrees of freedom

Number of iterations to convergence: 5 

Achieved convergence tolerance: 0.0001085
Rainbow trout (Oncorhynchus mykiss)

Tissue

0

10

20

30

40

50

0.1 1 10

Selenium in fish (μg/g whole body dry 

wt.)

Weight of whole fish (g)

reduction

 in growth

EC10 = 

2.19 μg/g 

0 %

5 %

10%

EC05 = 1.89 μg/g 

EC00 = 1.27 μg/g 

Rainbow trout 

Hilton et al. 1980

Figure 11. Relationship between growth of juvenile rainbow trout and concentration of selenium in their 

tissues after 140 days exposure to dietary selenium in the form of sodium selenite (Hilton et al. 1980; Table 

7 below). The biphasic model is that of Beckon et al. (2008).

Table 7. Weight of juvenile rainbow trout and concentration of selenium in their tissues after 140 days 

exposure to dietary selenium in the form of sodium selenite. Data are from Tables 2 and 3, and 

transcribed from Fig. 2 in Hilton et al. (1980). Whole body selenium was calculated from reported 

concentrations in carcass, kidney and liver.

Selenium 

in diet 

(μg/g dry 

diet)

Carcass 

Concentration 

Factor 

(from 

Hilton 

et al. 

Fig.2)

Selenium 

concentration 

in fish 

(μg/g 

carcass 

dry wt.)

Liver 

Concentration 

Factor

Hepatosomatic 

index at 

wk 4

Liver 

Se 

correction

Kidney 

Concentration 

Factor

Kidney 

Se 

correction

Selenium 

in fish 

(μg/g 

whole 

body dry 

wt.)

Weight

of 

whole 

fish (g)

0.07 3.55 0.249 8.5 1.4 0.0036 11.35 0.00282 0.2523 32

0.15 2.95 0.442 6.3 1.3 0.0061 9 0.00478 0.4489 35

0.38 1.35 0.513 6.5 1.3 0.0161 6.7 0.00902 0.5362 37

1.25 0.52 0.650 9.65 1.3 0.0784 2.9 0.01285 0.7386 41

3.67 0.37 1.358 11.9 1.3 0.2839 2.6 0.03381 1.6697 41

13.06 0.35 4.571 7.9 1.4 0.7222 2.8 0.12959 5.4037 14
nls(start = list(max=81.9998,eUp=0.82232,bUp=0.4387,eDn=3.3428,bDn=-2.56175),

control= list(tol=29,maxiter=50,minFactor=1/1024,printEval=FALSE,warnOnly =FALSE),

trace=TRUE, data = RainbowTroutTTF, formula = y~1.28+((max1.28)/(1+(eUp/x)^bUp))/(1+(eDn/x)^bDn))

Parameters:

 Estimate Std. Error t value Pr(>|t|)

max 81.9998 658.7795 0.124 0.921

eUp 0.8223 29.7913 0.028 0.982

bUp 0.4387 2.4779 0.177 0.888

eDn 3.3428 4.5195 0.740 0.595

bDn -2.5618 2.1202 -1.208 0.440

Residual standard error: 1.783 on 1 degree of freedom

Number of iterations to convergence: 0 

Achieved convergence tolerance: 28.12 

residual sum-of-squares: 3.178 (minimized manually)

Diet

0

10

20

30

40

50

0.01 0.1 1 10 100

Selenium in diet (μg/g dry wt.) Weight of whole fish (g)

Rainbow trout 

Hilton et al . 1980

reduction

 in growth

EC10 = 5.04 μg/g 

0%

5%

10%

EC05 = 4.22 μg/g 

EC00 = 2.41 μg/g 

as selenite 

Figure 12. Relationship between dietary concentration of selenium (as selenite) and weight (mass) of 

young rainbow trout (average initial mass 1.28 g) fed diets spiked with sodium selenite for 140 days

(Hilton et al. 1980; Table 7 above).
nls(start = list(max=75,eUp=.1,bUp=.17,eDn=14,bDn=-2.4),control= 

list(tol=.0001,maxiter=50,minFactor=1/1024,printEval=FALSE,warnOnly 

=FALSE),trace=TRUE,data = RainbowTroutTTF,formula = y~1.28+((max1.28)/(1+(eUp/diet)^bUp))/(1+(eDn/diet)^bDn))

Parameters:

 Estimate Std. Error t value Pr(>|t|) 

max 74.8106 125.7177 0.595 0.658 

eUp 0.4701 9.5920 0.049 0.969 

bUp 0.1684 0.2653 0.635 0.640 

eDn 9.1007 1.2964 7.020 0.090 .

bDn -2.7285 0.5476 -4.983 0.126 

---

Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1 

Residual standard error: 0.654 on 1 degree of freedom

Number of iterations to convergence: 8 

Achieved convergence tolerance: 2.743e-05

0

10

20

30

40

50

0.001 0.01 0.1 1 10 100

Selenium in diet (μg/g dry wt.) Weight of whole fish (g)

Rainbow trout 

Hilton et al . 1980, Vidal et al . 2005

reduction

 in growth

EC10 = 1.56 μg/g 

0%

5%

10%

EC05 = 1.01 μg/g 

EC00 = 0.310 μg/g 

as seleno-L-methionine equivalent

Figure 13. Relationship between dietary concentration of selenium (as seleno-L-methionine equivalent) 

and weight (mass) of young rainbow trout (average initial mass 1.28 g) fed diets spiked with sodium 

selenite for 140 days (Hilton et al. 1980). The seleno-L-methionine equivalent diets were calculated by 

using the whole body selenium concentration data in Hilton et al. (1980) and the bioaccumulation data 

from the experiment of Vidal et al. (2005) in which larval rainbow trout were fed seleno-L-methionine for 

90 days (Figure 14 and Table 8 below).
Rainbow trout

0.01

0.1

1

10

100

0.01 0.1 1 10 100

Selenium in diet (μg/g dry diet)

Selenium in fish (μg/g 

whole body dry wt.)

selenite (Hilton et al. 1980) 

seleno-L-methionine (Vidal et al. 2005) 

regression selenite

regression SeLMe

Figure 14. Selenium in the whole body tissue of young rainbow trout as a function of selenium in the diet 

in the form of either selenite (Hilton et al. 1980) or seleno-L-methionine (Vidal et al. (2005).

Table 8. Selenium in the diets of larval rainbow trout and selenium in their whole body tissue after 90 

days of exposure to dietary selenium in the form of seleno-L-methionine. Data are from Table 2 in Vidal et 

al. (2005), with dietary selenium (in red) calculated by adding background (control) selenium analysis to 

nominal (added) selenium. Whole body selenium on a dry weight basis (in red) was calculated from 

reported wet weight concentrations using 75.84 percent moisture as used in USEPA (2004).

Selenium 

in diet 

(μg/g dry 

wt.)

Selenium 

concentration 

in fish (μg/g 

whole body 

wet wt.)

Selenium 

concentration 

in fish (μg/g 

whole body 

dry wt.)

Weight 

of 

whole 

fish (g)

0.23 0.31 1.28 5.17

4.83 0.58 2.40 3.45

12.23 1.2 4.97 3.45

18.23 1.41 5.84 3.82
nls(start = list(max=77.073,eUp=0.03730,bUp=0.15925,eDn=5.5995,bDn=-0.8558),control= 

list(tol=30,maxiter=50,minFactor=1/1024,printEval=FALSE,warnOnly 

=FALSE),trace=TRUE,data = RainbowTrout,formula = y~1.28+((max1.28)/(1+(eUp/dietr)^bUp))/(1+(eDn/dietr)^bDn))

Parameters:

 Estimate Std. Error t value Pr(>|t|)

max 77.0730 513.0790 0.150 0.905

eUp 0.0373 3.1269 0.012 0.992

bUp 0.1593 0.8301 0.192 0.879

eDn 5.5995 22.1013 0.253 0.842

bDn -0.8558 0.7089 -1.207 0.440

Residual standard error: 1.808 on 1 degrees of freedom

Number of iterations to convergence: 0 

Achieved convergence tolerance: 29.92
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