. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. METABOLISM OF RADIOSTRONTIUM BY FISH 349 the integument in all cases is about the same, and the gills and muscles show little variation. The amount found in the visceral organs, however, is markedly differ- ent. The individual organs were not ashed and counted separately because of their very small size, so it is not possible to state in what organ or organs the very large percentage of Srso was located. Since marine fish in general swallow more water than do fresh water fish to maintain proper osmotic balance, it is possibl
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. METABOLISM OF RADIOSTRONTIUM BY FISH 349 the integument in all cases is about the same, and the gills and muscles show little variation. The amount found in the visceral organs, however, is markedly differ- ent. The individual organs were not ashed and counted separately because of their very small size, so it is not possible to state in what organ or organs the very large percentage of Srso was located. Since marine fish in general swallow more water than do fresh water fish to maintain proper osmotic balance, it is possible that the principal route of entry of the isotope in solution is by way of the gut. However, our direct feeding experi- o j= •21 25 in 2 20 O 15 X CO If) o> " K o 5. - o o o o_ o' o n o O O I 21 234567 14 Days in Sr89 sea water FIGURE 8. The uptake of Sr89 in solution by Tilapia mossambica, expressed as the concentration ratio. nients with a variety of fishes indicate that strontium is rapidly eliminated from all the visceral organs. How is it, then, that so much strontium remains in the visceral organs when the fish is immersed in the isotope? A probable explanation is that the fish is being fed the isotope continually, in effect, every time it swallows. Since the concentration of Sr89 was found to be higher in the sea water than in the fish, only a small amount of sea water present in the gut would account for the large percentage of total Sr89 which was found in the visceral organs. The concentra- tion of Sr89 in the sea water was X 10"2 /xc/ml. Assuming arbitrarily that 50 per cent of the total Sr89 of the fish was in the visceral organs (Fig. 9), this amount equals about 12 X 10~3 /xc/gram fresh weight of the organs. If only from ml. of sea water was present in the gut, this would account for the radioactivity. Please note that these images are extracted from scanned page images that may have been digitally enhan
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
