CAROTENOIDS 



The results of Hartmann et al. on S. irideus ova are included in this 

 table, and it will be seen that considerable inter-species differences 

 exist. 



Table 36 — Qualitative Carotenoid Distribution in Fresh Water Fish 



REFERENCES TO TABLE 36 



1. Gk)ODWlN, T. W. (1948), Unpublished observations. 



2. Goodrich, H. B., Hill, G. A., and Arrick, M. S. (1941), Genetics, 26, 573. 



3. Lederer, E. (1938), Bull. Soc. chim. Biol, 20, 554. 



4. Steven, D. M. (1950). Private communication. 



5. L5NNBERG, E. (1938), Ark. Zool, 30A, No. 6. 



6. S6RENSEN, N. A., and Stene, J. (1938), Kgl. Norske Videnskab. Selskab. Shifter, No. 9. 



7. Steven, D. M. (1948), J. exp. Biol., 25, 369. 



Formation and Metabolism 

 (i) Invertebrates 



The storage of carotenoids by fresh water amphipods may well 

 depend on the presence of light, for Beatty ^^ showed that whilst ephi- 

 gean amphipods store carotenoids, hypogean do not, although they 

 were not short of carotenoid-containing food. 



Beatty quotes two old reports which support his observations : 

 Gammarus puteanus and G. fluviatilis lose their colour when kept in the 

 dark for six months, whilst Niphargus puteanis becomes greenish when 

 transferred to light, although N. plateaui does not ; the dull transparent 

 white of Gammarus dueberi becomes flecked with red spots when exposed 

 to light. 



(ii) Fish 



Although it is probably true that the extreme variations in the pig- 

 mentation of trout are due to genetic factors, it is also true that the 

 lipochrome pigments are of alimentary origin. 



204 



