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Table 2 Reproduction of 14-day-old Daphnia magna exposed for 8 days to ibuprofen

From: Systems biology meets stress ecology: linking molecular and organismal stress responses in Daphnia magna

 

Brood

Control

20 mg/l ibuprofen

40 mg/l ibuprofen

80 mg/l ibuprofen

Brood release and adult moultinga (age [days])

3rd

15.0 ± 0.00

15.2 ± 0.20

15.2 ± 0.20

15.2 ± 0.20

 

4th

18.2 ± 0.20

18.4 ± 0.24

18.6 ± 0.24

18.4 ± 0.24

 

5th

21.2 ± 0.20

21.4 ± 0.24

21.4 ± 0.24

21.2 ± 0.20

Fecundity (average number of offspring/brood)

3rd

22.8 ± 1.59

19.6 ± 2.42

18.8 ± 2.82

24.6 ± 3.14

 

4th

28.4 ± 1.40

30.0 ± 0.95

8.20 ± 1.43*

0.00 ± 0.00*

 

5th

42.0 ± 1.64

41.4 ± 2.25

6.60 ± 1.54*

1.00 ± 0.45*

Embryo abortion (average number of abortions/brood)

3rd

Nil

Nil

Nil

Nil

 

4th

Nil

Nil

Observedb

Observedb

 

5th

0.20 ± 0.20

0.20 ± 0.20

7.20 ± 3.20

20.6 ± 7.08*

Production of male offspringc

3rd

Na

NA

NA

NA

 

4th

Nil

Nil

Nil

Nil

 

5th

Nil

Nil

Nil

Nil

  1. Values are expressed as mean ± standard error (n = 5). Asterisks (*) denote a significant (P < 0.05, analysis of variance) difference from controls. aMoulting follows brood release in mature female daphnids and was assessed by counting shed carapaces (after moulting new eggs are deposited from the ovaries into the brood chamber with the incubation period corresponding to the intermoult period). bAborted embryos were not quantified, but a few were observed in 40 mg/l ibuprofen, and considerable numbers in 80 mg/l ibuprofen, comparable to 5th brood. cFourth and fifth brood neonates were reared to adulthood (about 9 days) in uncontaminated media until every individual had produced their first brood. NA, not applicable.