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> I have also heard of the "bent" fish due to increase gas in solution > just below dams. > I haven't read much about this but happened to have a couple of references in my database. It looks like fish can get DCI just like everybody else, thus bringing into question Des Gorman's assertion that "the only animals that are fit to dive are fish". I wonder how it affects their brain function (remembering of course that fish have no cerebral cortex)? /Rat ------------------------------------------------------------ Speare DJ (1991) Endothelial lesions associated with gas bubble disease in fish. J Comp Pathol 104:327-335 Two groups of healthy chinook salmon (Oncorhynchus tshawytscha) were experimentally exposed to gas supersaturated groundwater. Gross lesions consistent with gas bubble disease (GBD) developed. Vascular lesions associated with intravascular gas bubbles were examined with light and scanning electron microscopy. Dermal blood vessels containing gas bubbles were severely dilated. Additionally, the gas bubbles were spatially associated with endothelial lesions ranging from cellular degeneration to exfoliation. The resulting regions of exposed subendothelial connective tissue were sparsely covered by small unidentified adherent cells and strands of fibrin. In the light of these findings, the similarities in vascular pathology between GBD in fish and decompression disease in man are discussed, particularly with respect to the initiation of haemostatic disorders in both conditions. ----------------------------------------------------------- McDonough PM, Hemmingsen EA (1985) Swimming movements initiate bubble formation in fish decompressed from elevated gas pressures. Comparative Biochemistry and Physiology 81:209-212 Young specimens of trout, catfish, sculpin and salamanders were equilibrated with elevated gas pressures, then rapidly decompressed to ambient pressure. The newly hatched forms tolerated extremely high gas supersaturations; equilibration pressures of 80-120 atm argon or 150-250 atm helium were required for in vivo bubble formation. During subsequent larval development, the equilibration pressures required decreased to just 5-10 atm and bubbles originated in the fins. Anesthetising older fish before decompression prevented bubble formation in the fins; this suggests that swimming movements mechanically initiate bubbles, possibly by a tribonucleation mechanism. ----------------------------------------------------------------
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