X-RAY-MICROANALYSIS OF ALUMINUM IN PUMPKINSEED GILLS

Energy dispersive X-ray micro-analysis was applied to study the (sub-) cellular distribution of aluminium at the gill level of ''acid-resist ant pumpkinseeds (Lepomis gibbosus) exposed to acidified water (pH = 4 .2) and an elevated level of aluminium (1.4 mg Al/l, exposure period = 21 days). Electron dense deposits, located in invaginations as well a s inside the gill tissue, were shown to contain elevated levels of alu minium and phosphorus. The micro-analytical findings suggest that the pumpkinseed possesses a defence mechanism, in which the intracellular accumulation of aluminium is limited to restricted sites and to storag e in macrophages.