Table 3. — Summairy of trimethylamlne oxide content of 

 marine and fresh-water animals 



1/ Where two or more values are reported for a species the mean of 

 these was used to represent the range and to calculate the standard devia- 

 tion. 



2/ The steuidard deviation was calculated using the relationship 



£x2 - (^x)- 

 N 



where (x) is the content of oxide in milligrams per 

 100 g. and (N) is the number of species considered. 



Teleosts . — The mean freezing-point depression for the fluids of 

 the marine teleost is about -O.7* C., and that for sea water is about 

 -2.0* C. or more. Since the depression of the freezing point varies pro- 

 portionately with osmotic pressure, the marine teleost must eliminate 

 metabolic products from its tissues against an osmotic-pressure gradient 

 (Baldwin I95I) . 



The content of trimethylamine oxide in blood plasma of the 

 teleost is low compared to that in the blood plasma of the elasmobranch . 

 The following values have been reported: Lophius piscatorius 12-17 mg. 

 N/lOO ml. (Briill and Nizet 195^), Sebastodes sp. negligible, Scorpaenichthys 

 marmoratus negligible, and Pleuronectidae sp. negligible (Horris and Benoit 

 1914.5a) . The small amount of oxide in the teleost blood and the lower 

 osmotic pressure of this blood compared with sea water make it appear 

 unlikely that trimethylamine oxide functions as an osmoregxilator . There 

 are, however, several observations that suggest this function. Smith 

 (1958), in the course of Arctic studies, foxmd that the freezing point 

 depression for fluid in the tissue of Arctic teleosts that live near the 



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