Declines in reproductive condition of male largemouth bass (Micropterus salmoides) following seasonal exposure to estrogenic endocrine-disrupting compounds

International Journal of Molecular Sciences
By: , and 

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Abstract

Reproductive abnormalities, that could lead to possible effects at the population level, have been observed in wild fish throughout the United States, with high prevalence in largemouth bass (LMB; Micropterus salmoides) and smallmouth bass (Micropterus dolomieu). Estrone (E1) and atrazine (ATR) are common environmental contaminants often associated with agricultural land use. 17alpha-ethinylestradiol (EE2) is a contaminant associated with wastewater treatment effluent, and a representative, well-studied estrogen commonly used for fish toxicity testing. Our objective was to assess whether early gonad recrudescence in adult fish was a period of sensitivity for alterations in reproductive condition and function. Adult male LMB were exposed from post-spawning to early gonad recrudescence to either a mixture of E1 (47.9 ng/L) + ATR (5.4 µg/L), or EE2 (2.4 ng/L) in outdoor experimental ponds. Gonad samples were collected from fish just prior to the start of exposure (July), at the end of the exposure period (December), the following spring just prior to spawning (April), and post spawning (May). Gonadosomatic index (GSI) was significantly reduced in E1 + ATR-exposed and EE2-exposed males compared to control at every post-exposure time point. Reduced sperm count and sperm motility were observed in the mixture treatment (E1 + ATR) compared to the control. Sperm motility was also reduced in the EE2 treatment. These data together indicate that estrogenic endocrine-disrupting compounds can lessen the reproductive condition of adult male LMB, and that effects of exposure during early gonad recrudescence can persist at least through the subsequent spawning cycle.
Publication type Article
Publication Subtype Journal Article
Title Declines in reproductive condition of male largemouth bass (Micropterus salmoides) following seasonal exposure to estrogenic endocrine-disrupting compounds
Series title International Journal of Molecular Sciences
DOI 10.3390/ijms232416131
Volume 23
Issue 24
Year Published 2023
Language English
Publisher MDPI
Contributing office(s) Columbia Environmental Research Center, Wetland and Aquatic Research Center
Description 16131, 9 p.; Data Release
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