Renal changes in selenium-exposed fish

Area of Science:

• Environmental toxicology
• Aquatic biology
• Histopathology

Background:

• Selenium is an essential trace element but can be toxic at elevated concentrations.
• Aquatic ecosystems can accumulate high levels of selenium from various sources.
• Green sunfish (Lepomis cyanellus) are common freshwater fish that can bioaccumulate contaminants.

Purpose of the Study:

• To investigate the histopathological and ultrastructural effects of chronic selenium exposure on green sunfish kidneys.
• To compare kidney pathology in fish from a selenium-rich lake with those from a control lake.

Main Methods:

• Collection of green sunfish from a selenium-rich lake and a control lake in east Texas.
• Analysis of kidney tissues using histopathological and ultrastructural examination.
• Quantification of selenium levels in fish kidneys.

Main Results:

• Fish from the selenium-rich lake had significantly higher kidney selenium concentrations (average 11 ppm).
• Histopathology revealed proliferative glomerulonephritis and hematuria in fish from the selenium-rich lake.
• Ultrastructural analysis showed vacuolation and necrosis of convoluted tubule cells in exposed fish.

Conclusions:

• Elevated environmental selenium levels in east Texas lakes cause significant kidney damage in green sunfish.
• The observed kidney pathologies indicate a toxicological impact of selenium on renal function in this species.
• This study underscores the importance of monitoring selenium levels in aquatic environments to protect fish health.