Lifelong Exposure to Dioxin-Like PCBs Alters Paternal Offspring Care Behavior and Reduces Male Fish Reproductive...

Area of Science:

• Environmental toxicology
• Ecotoxicology
• Reproductive toxicology

Background:

• Paternal contribution to offspring success is crucial in species with paternal care.
• Polychlorinated biphenyls (PCBs) are persistent contaminants affecting reproduction.
• Effects of PCBs on male reproductive success, particularly in paternal care species, are understudied.

Purpose of the Study:

• To investigate the impact of lifelong polychlorinated biphenyl (PCB) exposure on male fathead minnow reproductive processes.
• To assess how PCBs affect endocrine function, physical traits, courtship, paternal care, and offspring survival in males.

Main Methods:

• Exposure of male fathead minnows (Pimephales promelas) to PCBs throughout their lifespan.
• Evaluation of endocrine-associated gene expression, testes histology, secondary sexual traits, and courtship behavior.
• Observation of paternal care behaviors (nest attendance, embryo tending) and offspring survival rates.

Main Results:

• PCBs reduced male secondary sexual characteristics but did not impact gonadal endpoints or courtship ability.
• High PCB concentrations altered gene expression and significantly reduced paternal care behaviors.
• PCB-exposed males exhibited higher embryo mortality, linked to decreased nest attendance and embryo tending.

Conclusions:

• PCBs impair male reproductive success in fathead minnows through complex interactions affecting gene expression, physical traits, and behavior.
• Reduced paternal care and increased embryo mortality due to PCB exposure can potentially suppress fish populations.