FRESH WATER ANIMALS: DEPOSITS: AMPHIBIA 



provided that astaxanthin is the naturally-cocurring hormone, In fact, 

 no demonstration of its presence in the ovarial fluid, which was used as 

 the natural source of Gi, was presented. It was reported that the fluid 

 was pale yellow ; the presence of astaxanthin in the fluid in 'the con- 

 centrations found active in this experiment should have imparted a 

 much stronger colour to it. 



It will be very interesting to see if other workers will confirm these 

 findings, but it appears already that preliminary work has failed to 

 do so. 13 



A logical difficulty arises with regard to this work of Hartmann et al. 

 When the earlier reports from the same laboratory on the gamones 

 present in sea urchin eggs are considered, it is found that echinochrome 

 (2-ethyl-3, 5, 6, 7, 8, — pentahydroxy-1, 4-naphthoquinone) in the 

 form of a protein complex exhibited all the properties attributed to 

 astaxanthin in the trout. This is in spite of the fact that sea urchin 

 eggs are very rich in carotenoids (see p. 163) but do not always contain 

 echinochromes. Carotenoids were, however, not tested for gamone 

 activity in sea urchins. 



The whole problem of the function of carotenoids in reproduction is 

 obviously in a very interesting state and the next few years should 

 considerably clarify the position. The present position has recently 

 been reviewed.^ ^ 



In Respiration 



It has recently been stated that amongst the carp family, carotenoids 

 accumulate mostly in the eggs of those species living under conditions 

 of poor oxygen supply. This has been taken to mean that carotenoids 

 function as a supplement to the embryonic circulation and furthermore, 

 that the pigmentation of fish is an indication of the amount of oxygen 

 available to them.^^A 



DEPOSITS 



In 1932 Trask^i encountered carotenoids in an algal deposit from a 

 lake in North Florida in water less than 30 cm. deep. 



Baudisch and von Euler ^ ^ examined two types of peat-like deposits 

 (** gyttja ") located near Stockholm. The red and green algal gyttja 

 contained only carotene whilst the -'' littoralgyttja " (detritus gyttja) 

 contained only xanthophylls. Both deposits are formed from materials 

 rich in both xanthophylls and carotenes and the suggestion has been 

 made that in the littoral peat, which is rich in CaCOg, ** natural ** 

 chromatography has been in operation, xanthophylls but not carotenes 

 being adsorbed on the CaCOg ; an explanation for the accumulation 

 of carotenes in algal deposits has not been oflFered. 



209 



