Morphological abnormalities during early-life development of the estuarine mummichog, Fundulus heteroclitus, as an indicator of androgenic and anti-androgenic endocrine disruption

We tested the hypothesis that gross morphological abnormalities are a sensitive indicator of exposure to waterborne androgenic and anti-androgenic compounds during embryonic, larval and juvenile stages of development in the common estuarine killifish, the mummichog (Fundulus heteroclitus; Pisces: Cyprinodontidae). Static exposures with daily renewal were carried out with 10-100,000 ng/L of the androgen agonist, 17alpha-methyltestosterone (MT), or the androgen antagonist, cyproterone acetate (CA), for 60 days post-fertilization (PF) in duplicate exposures. Measured concentrations were 78.4-155.8% of nominal concentrations for MT and 13.5-168.1% for CA. No dose-related or consistent effects of MT or CA were observed before hatch. In 60 days PF juveniles, incidence of skeletal abnormalities (scoliosis, lordosis, head, facial and fin), soft tissue abnormality (anal swelling) and hemorrhaging were significantly increased by MT but only at high concentrations (greater than or equal to 1000 ng/L). The 10,000 and 100,000 ng/L concentrations of MT produced a wider range of abnormalities than 1000 ng/L. Over 90% of fish exposed to 10,000 or 100,000 ng/L were abnormal with an average of over 3.5 abnormalities per fish. CA did not increase the incidence of any type of abnormality. Survival of juveniles to the end of the exposure was reduced by MT at concentrations of 1000 ng/L and greater in the first experiment and at concentrations of 10,000 ng/L and greater in the second experiment. Juvenile length was reduced by high concentrations of MT (greater than or equal to10,000ng/L) in the first experiment and by most concentrations in the second experiment. We conclude that morphological abnormalities in early-life stages of mummichogs are not a sensitive indicator of exposure to androgenic or anti-androgenic waterborne EDSs at environmentally relevant concentrations. Crown Copyright (C) 2004 Published by Elsevier B.V. All rights reserved.