developed in the fish first exposed to .010 and 

 .0056 ppm DDT. 



The physical signs of stress exhibited by 

 fish in DDT, include hyperexcitability and loss 

 of muscular control, the presence of yolk sacs 

 in the guppies bom in DDT, the failure of the 

 sac resorption in trout fry exposed to DDT, and 

 various histopathological conditions found in the 

 tissues. This syndrome suggests that DDT has 

 a direct effect on adrenal tissue, especially that 

 portion secreting the glucocorticoids . The most 

 marked histopathological conditions in the fish 

 attributed to the DDT were found in the liver, 

 the intestine, and the adrenal -like tissue in the 

 kidney. Modification of the kidney tubules and 

 the gross appearance of the spleen were occa - 

 sionally observed. 



There is a very serious need for exten- 

 sive study of the chlorinated hydrocarbons and 

 their effects on fish survival, reproductive 

 potential, and physiological condition as ex- 

 hibited by the tissues. There are many factors 

 in the field which modify bioassay determina - 

 tions. It is likely that the safe dosages of 

 insecticides for fish will be less than that neces- 

 sary for insect control . If such is found to be 

 the case, recourse to other means of control of 

 the insects will be necessary to prevent exten- 

 sive loss of fish. 



LITERATURE CITED 



Adams, L., M. G. Haravan, N. W. Hosley, 

 and D. W. Johnston. 

 1949. The effects on fish, birds, and 

 man of DDT used in control of forest 

 insects in Idaho and Wyoming. Journal 

 of Wildlife Management, vol. 13, p. 

 245-254. 



Andrew, W. 



1959. Textbook of Comparative 



Histology. Oxford University Press, 

 New York, chap. 13, p. 527-530. 



Anonymous. 



1951. Insecticide storage In adipose 

 tissue. Journal of the American 

 Medical Association, vol. 145, p. 

 735-736. 



Anonymous. 



1960. A. I. E. C. holds pesticide 

 symposium . Agricultural Chemicals, 

 vol. 15, p. 8. 



Baxter, J. T. 



1959. Some observations on the histo- 

 pathology of aldrin poisoning in lambs. 

 Journal of Comparative Pathology and 

 Therapeutics, vol. 69, p. 185-191. 



Bell, J. T., Jr. 



1961 . Histological and histochemical 

 effects of DDD on goat adrenals, 

 pituitaries, livers, and kidney. 

 American Association of Anatomists, 

 Anatomical Record, vol. 139, p. 207. 



Brown, M. E. 



1957. The Physiology of Fishes. 

 Academy Press, Inc., New York, vol. 1, 

 chap. 6, p. 252 -254. 



Breder, C. M., Jr., andC. W. Coates. 



1932 . A preliminary study of population 

 stability and sex ratio of Lebistes . 

 Copeia, p. 147 - 155. 



Clawson, S. G. 



1958 . Wild turkey populations on an 

 area treated with heptachlor and 

 dieldrin. Alabama Birdlife, vol.6, 



p. 4-8. (Cited by DeWitt^al_., 1960.) 



Cope, O. B. 



1959 . The retention of DDT by trout and 

 whitefish. Biological Problems in Water 

 Pollution, U.S. Department of Health, 

 Education and Welfare. 



Cope, O. B., C. M. GjuUin, and A. Storm. 

 1947. Effects of some insecticides on 

 trout and salmon in Alaska with refer- 

 ence to blackfly control. Transactions 

 American Fisheries Society, vol. 77, 

 p. 160- 177. 



Cottam, C. and E. Higgins. 



1946. DDT: Its effects on fish and wild- 

 life. U. S. Department of the 

 Interior, Fish and Wildlife Service, 

 Circular 11, 14 p. 



15 



