skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: A histological and ultrastructural study of the effects of low pH aluminum upon the gills of the Atlantic salmon

Thesis/Dissertation ·
OSTI ID:7067591

Atlantic salmon (Salmo salar) inhabit freshwater during part of their life cycle, and can be exposed to low pH and aluminum concentrations that disturb gill functions such as ion regulation, acid base balance, and gas exchange in fish. Electron microscopy showed that exposure of fry to 75 {mu}g/l or more inorganic aluminum at pH 5.5 caused hyperplasia and development of apical crypts in chloride cells, which are involved in ion transport. Fusion of primary and secondary lamellae was observed. These effects would interfere with gill function. Abnormalities did not occur when humic acid was present to chelate aluminum, suggesting that only the inorganic form is toxic. Morphometric analysis of gills from smolts exposed to low pH and aluminum in artificial channels revealed that fish exposed to pH 5 to 6 without aluminum had more chloride cells on primary and secondary lamallae than controls. Fish exposed to aluminum at pH 5 to 6 had more primary lamellar chloride cells than controls, but the number of secondary lamellar chloride cells did not increase. Exposure to aluminum damages chloride cells, and their numbers decrease as these are lost from secondary lamellae.

Research Organization:
Maine Univ., Orono, ME (USA)
OSTI ID:
7067591
Resource Relation:
Other Information: Thesis (Ph. D.)
Country of Publication:
United States
Language:
English