Aquatic Toxicology

The effects of model androgen 5α-dihydrotestosterone on mummichog (Fundulus heteroclitus) reproduction under different salinities

Publication date: August 2015
Source:Aquatic Toxicology, Volume 165
Author(s): Chelsea O. Glinka, Salvatore Frasca, Anthony A. Provatas, Tanya Lama, Sylvain DeGuise, Thijs Bosker
Endocrine disrupting substances (EDSs) have the potential to disturb sensitive hormone pathways, particularly those involved in development and reproduction. Both fresh and estuarine water bodies receive inputs of EDSs from a variety of sources, including sewage effluent, industrial effluent and agricultural runoff. Based on current literature, freshwater species appear to respond to lower levels of EDSs than estuarine or marine species. Therefore, effects elicited by EDSs in freshwater teleosts may not be an accurate representation of how EDSs affect teleosts in estuarine and marine environments. To address this potential difference, a short-term reproductive bioassay was conducted under conditions of low and high salinity using mummichog (Fundulus heteroclitus), a euryhaline species that is native to the east coast of North America. The goals of this study were to determine the response of mummichog when exposed to an androgenic EDS and whether salinity affected the response. A model androgen, 5α-dihydrotestosterone (DHT), was selected for this experiment. Impacts on reproduction were evaluated at multiple biological levels, including physiological (sex steroid levels), organismal (gonad size and gonad morphology), and functional (egg production) endpoints. Under conditions of high salinity, egg production was significantly reduced at all exposure concentrations. Under conditions of low salinity, there were no significant differences based on DHT treatment; however, egg production in all treatment groups including the control were significantly reduced relative to the high salinity control group. Other reproductive endpoints, such as sex steroid production, showed stronger correlation to fecundity in females than males. This study demonstrates that mummichog fecundity is sensitive to androgenic endocrine disruption while also underscoring the importance of how changes in salinity, an environmental variable, can impact reproduction.

Glossaire technique

Un déversement liquide ou gazeux de déchets dans l'environnement.
Qui vit principalement dans la partie inférieure d'une rivière ou estuaire...
Organisme aquatique qui a la faculté de supporter des changements...
Substance produite dans un organe (glande endocrine) et transportée par la...
Se réfère à la mer, depuis la haute mer jusqu'au niveau de la marée haute...
Fonction par laquelle les êtres vivants perpétuent leur espèce. Mécanisme...
Les thons sont des poissons océaniques de la famille des scombridés :...