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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.