oxide in marine animals, a short discussion of its occurrence in fresh- 

 water animals is included for cosnparison. 



Occurrence in Marine Animals 



Table 1 gives the content of trimethylaaaine oxide in a numher 

 of marine animals. The oxide has been found in a coelenterate, an echl- 

 noderm, some molluscs, all Crustacea, all elasmobranchs, most teleosts, 

 a reptile, and two mannals. Trimethylamlne oxide is not found in marine 

 plants; however, trimethylamlne and dlmethylamlne are found in matrine 

 algae ( Kapeller- Adler and Vering 1931) • 



Table 3 gives the mean, range, and standard deviation of 

 trimethylamlne oxide in the major groups of marine animals. The mean content 

 of trimethylamlne oxide is 13^*5 mg.N/lOO g. in the elasmobranchs. The mean 

 content of the oxide in the marine teleosts, Crustacea, molluscs, and fresh- 

 water teleosts is, respectively, about OAl, 0.32, 0.26, and -^D.l that of 

 the elasmobranchs. 



There is a wide variation in oxide content among the species 

 that compose each group of animals. Values of 38 "to 6k mg.H/lOO g. have 

 been reported for sprat, Clupea sprattus (Ronald and Jakobsen ISk'j) , whereas 

 values of 3 and k mg. N/lOO g. have been reported for albacore, Germo 

 alalunga , and bluef in tuna, Thunnus thynnus , respectively (Kawabata 1953) • 

 Shewan (^1951) has reported that the mean content of oxide in Arctic specimens 

 is higher than that found in North Sea specimens of the same species. 



Seasonal variations in oxide content of herring have been observed 

 by Ronald and Jakobsen (19^7) • They have reported that the oxide content 

 in the tissue in winter is up to 100 percent greater than that found in 

 summer. 



The mean content of oxide in cod, Gadus morrhua, haddock, Gadus 

 a^glefinus , and whiting, Gadus merlangus , is greater in large than in small 

 fish. 



Uneven distribution of the oxide in different parts of the fish 

 has been observed ( Shewan 1951^ Suyama and Tokuhiro 195^4-). The dark lateral 

 line of the flesh of herring and tunny contains only about half as much 

 triaethylami ne oxide as is found in the rest of the muscle. 



Aside from the differences in diet among the various species, no 

 explanation can be given for the differences in trimethylamlne oxide con- 

 tent correlated with geographic area, season, or size of the fish. The 

 finding of a tissue trimethylamlne oxide reductase in the dark meat of 

 albacore, Germo alalunga , and frigate-mackerel tissue, Auxis tapeinoscana, 

 (Kawabata 19537 suggests that the variation in content between different 



?arts of the fish is due to the enzymatic breakdown of trimethylamlne oxide 

 o trimethylamlne. Other investigators have been xmable to show that tri- 

 methylamlne oxide is reduced in swordfish, cod, and halibut muscle (Anderson 

 and Fellers 19^9, Shewan and Jones 1957, Tarr 1939). 



