CHAPTER V 



MARINE INVERTEBRATES 



Having discussed the plant carotenoids starting with the higher land 

 plants and ending with the lower aquatic plants, it will be convenient 

 to discuss animal carotenoids in the reverse order, beginning with 

 marine invertebrates. 



As the discussion proceeds it will be clear that the carotenoids of 

 marine invertebrates are of two types : 



(a) those derived directly or indirectly from plants eaten as food, and 



(b) those, characteristic of the animal species, which are produced 

 either by altering alimentary carotenoids or de novo. It is by no 

 means proved which of these processes does, in fact, occur, but, 

 from evidence obtained with higher animals, it is extremely 

 unlikely that carotenoids are produced de novo in invertebrates. 



Lederer^ has provided a complete account of the knowledge of animal 

 carotenoids up to 1935. This monograph is extremely useful because 

 of the detailed critical discussion of much of the early work. 



PROTOZOA 



According to Fox, ^ phytozoa give rise to the conspicuous yellow, 

 orange, and red colours observed in rain ponds, lakes, salt ponds, sea 

 patches and in snow. Chetton, Lwoff and Parat ' state that parasitic 

 infusorians acquire carotenoid pigmentation by eating the eyes of 

 certain Crustacea. 



METAZOA 

 PoRiFERA (Sponges) 



The pioneer investigators in the field of animal pigments, Krukenberg 

 and McMunn, detected carotenoids in a number of sponges which are 

 listed by Lederer. ^ Lonnberg * has detected carotenoids in Halichon- 

 dria panicea, Suherites ficus, Dysidea fragilis and Axinella rugosa. 



Although in recent reports there are noted some occasional diver- 

 gences the interesting point emerges that in the sponges the carotenes 



155 



