. Bulletin. Natural history; Natural history. June, 1971 Reinbold et al. : Biodegradability of DDT and Methoxychlor 409. T 10 15 20 EXPOSURE TIME (DAYS) T 30 Fig. 1, — Comparative uptake from water of "C-DDT and 'H-methoxychlor by tilapio. Tfie vertical arrows indicate the days when fish were transferred to jars containing insecticide levels equivolent to those which the fish had been placed in at the beginning of the experiment. the insecticide concentration in me- thoxychlor-exposed fishes reached an equihbrium, which indicated that the compound was being metaboUzed and excreted, DDT wa
. Bulletin. Natural history; Natural history. June, 1971 Reinbold et al. : Biodegradability of DDT and Methoxychlor 409. T 10 15 20 EXPOSURE TIME (DAYS) T 30 Fig. 1, — Comparative uptake from water of "C-DDT and 'H-methoxychlor by tilapio. Tfie vertical arrows indicate the days when fish were transferred to jars containing insecticide levels equivolent to those which the fish had been placed in at the beginning of the experiment. the insecticide concentration in me- thoxychlor-exposed fishes reached an equihbrium, which indicated that the compound was being metaboUzed and excreted, DDT was increasingly con- centrated in the fishes. In tilapia ex- posed to the insecticide level at the end of 31 days, even after the DDT had been concentrated 10,600 times it had not reached a steady state. Furthermore, when tilapia were held in water containing ppm of insec- ticide for 12 days and subsequendy were left for 15 days in jars containing water with no insecticide, the radio- active compounds in methoxychlor-ex- posed fish were rapidly excreted (Fig. 4). At the end of 15 days in uncon- taminated water there was a 10,000- fold difference between the concentra- tions in tilapia of methoxychlor and of DDT (Table 4). The metabolic pattern (Table 2) in- dicates that both fishes metabolized methoxychlor to a greater extent than they did DDT. Tilapia metabolized DDT to a greater extent than green sunfish metabolized it. Tilapia contain- ed DDD as a major metabolite, but the major metabolite of the green sun- fish was DDE. Methoxychlor was rapidly metabolized by tilapia, which contained considerably higher propor- tions of the mono-O-demethylated prod- uct [2- (p-methoxyphenyl) - 2 - (p-hy- droxyphenyl) -1, 1,1- trichloroethane]. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Illinois. Natu
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