shown that the fish contained a relatively low 

 level of thiaminase activity. In this case, the 

 mink rancher would cook the fish to be on the 

 safe side. According to the results of research 

 by Gnaedinger and Krzeczkowski ( 1966) , it ap- 

 pears that fish with various concentrations of 

 thiaminase activity all have to be heated to 

 about the same temperature time relationship 

 to give complete destruction of thiaminase ac- 

 tivity. Therefore, a mink rancher probably 

 should not give fish with "low" levels of thi- 

 aminase a milder heat treatment than fish with 

 "high" levels of thiaminase. 



Different analytic methods were used by the 

 various researchers to obtain the data pre- 

 sented in the tables. That is, the presence or 

 absence of thiaminase was observed through 

 various chemical methodologies or biological 

 feeding studies; it is possible that one method 

 of detection could show the presence of thi- 

 aminase, whereas another method would show 

 that the thiaminase was absent in the animal. 

 Generally, the chemical methods for thiaminase 

 activity are believed capable of detecting low- 

 er levels of thiaminase than the biological 

 methods. 



LITERATURE CITED 



1. AMERICAN FISHERIES SOCIETY. 



1960. A list of common and scien- 

 tific names of fishes from the Unit- 

 ed States and Canada. 2nd ed. 

 Amer. Fish. Soc. Spec. Publ. 2, 102 p. 



2. BORGSTROM, G. 



1961-1965. Fish as food. 4v. vol. 1. 

 Production, biochemistry, and mi- 

 crobiology. Academic Press, New 

 York, 441 p. 



3. DEUTSCH, H. F., and A. D. HASLER. 



1943. Distribution of a vitamin Bi 

 destructive enzyme in fish. Proc. 

 Soc. Exp. Biol. Med. 53: 63-65. 



4. GNAEDINGER, R. H. 



1965. Thiaminase activity in fish: 

 An improved assay method. U.S. 



Fish. Wildl. Serv., Fish. Ind. Res. 

 2(4): 55-59. 



5. GNAEDINGER, R. H., and R. A. 



KRZECZKOWSKI. 

 1966. Heat inactivation of thiaminase 

 in whole fish. Commer. Fish. Rev. 

 28(8): 11-14. 



6. GREEN, R. G., C. A. EVANS, and 



W. E. CARLSON. 

 1937. A summary of Chastek paral- 

 ysis studies. Minn. Wildl. Dis. In- 

 vest. 3: 173-177. 



7. JONES, W. G. 



1960. Fishery resources for animal 

 food. U.S. Fish Wildl. Serv., Fish. 

 Lean. 501, 22 p. 



8. LEE, C. F. 



1948. Thiaminase in fishery products: 

 A review. Commer. Fish. Rev. 

 10(4): 7-17. 



9. LEE, C. F., and W. CLEGG. 



1955. Technical Note No. 31 — 

 Weight range, proximate composi- 

 tion and thiaminase content of fish 

 taken in shallow water trawling in 

 northern Gulf of Mexico. Commer. 

 Fish. Rev. 17(3): 21-23. 



10. MELNICK, D., M. HOCHBERG, and 



B. L. OSER. 

 1945. Physiological availability of the 

 vitamins. II. The effect of dietary 

 thiaminase in fish products. J. Nutr. 

 30(2): 81-88. 



11. NEILANDS, J. B. 



1947. Thiaminase in aquatic animals 

 of Nova Scotia. J. Fish. Res. Bd. 

 Can. 7(2): 94-99. 



12. STOUT, F. M., J. E. OLDFIELD, and 



J. ADAIR. 

 1963. A secondary induced thiaminase 

 deficiency in mink. Nature 197 

 (4869): 810-811. 



13. WOLF, L. D. 



1942. Fish diet disease of trout. A 

 vitamin deficiency produced by diets 

 containing raw fish. N.Y. State 

 Conserv. Dep., Fish. Res. Bull. No. 2. 



