Oestrogens have no hormonal effect on the development and reproduction of the harpacticoid copepod Nitocra spinipes.
In recent years, reports have described endocrine-disruptive effects of environmental oestrogens in fish, but little is known about similar effects in crustaceans. The objective of the present study was therefore to examine whether the oestrogens 17-beta-oestradiol, 17-alpha-ethynylestradiol and diethylstilbestrol (DES), could affect mortality, larval development rate, fecundity and sex ratio in the sexually reproducing harpacticoid copepod Nitocra spinipes. Newly released nauplii (<24-h old) were exposed to 1/1,000, 1/100 and 1/10 (nominal concentrations) of each oestrogen's 96 h-LC50 value for < or = 18 days at 22 +/- 1 degrees C. The percentage of gravid females and the number of developed copepodites were both reduced at 0.03 mg l(-1) DES, although the latter response was not significant. None of the other two oestrogens induced any measurable effects. Since the only observed significant response appeared at a DES concentration no more than 10 times below the 96 h-LC50 value, there is no evidence of endocrine-disruptive activity in N. spinipes exposed to oestrogens.
Breitholtz
M
M
Institute of Applied Environmental Research (ITM), Stockholm University, Stockholm, Sweden. magnus.breitholtz@itm.su.se
Bengtsson
B E
BE
D000818:Animals; D003445:Crustacea / Q000187:drug effects / Q000502:physiology*; D004054:Diethylstilbestrol / Q000633:toxicity; D004958:Estradiol / Q000633:toxicity; D045166:Estradiol Congeners / Q000633:toxicity; D004967:Estrogens / Q000633:toxicity*; D004968:Estrogens, Non-Steroidal / Q000633:toxicity; D004997:Ethinyl Estradiol / Q000633:toxicity; D005260:Female; D005298:Fertility / Q000187:drug effects; D007814:Larva / Q000187:drug effects / Q000254:growth & development; D007928:Lethal Dose 50; D008297:Male; D011247:Pregnancy; D012098:Reproduction / Q000187:drug effects; D018675:Toxicity Tests
D045166:Estradiol Congeners; D004967:Estrogens; D004968:Estrogens, Non-Steroidal; D004997:Ethinyl Estradiol; D004958:Estradiol; D004054:Diethylstilbestrol