Chapter IMC 



THE B VITAMIN REQUIREMENTS OF ANIMALS 

 AND PLANTS 



Requirements of Invertebrates 



Biochemistry in the broadest sense is concerned with the chemistry of 

 all living species. Generally, however, biochemical investigations have 

 been most intense in those fields that seem the most likely to bring the 

 accomplishment of immediate results. Coupled with this, the ever urgent 

 need for deeper insight into the factors involved in human nutrition, and 

 to a lesser extent in the nutrition of domestic animals, has resulted in a 

 neglect in the study of the nutritional requirements of invertebrates. 



In very recent years, however, a number of factors have brought about 

 some change for the better in this regard. In the first place, commercial 

 interests, increasingly mindful of the economic benefits of research, have 

 diverted investigations in several cases into this field of inquiry. The 

 manufacturers of insecticides and those in the sea-food industries have thus 

 taken an active interest in what quite recently was purely an academic 

 subject. Secondarily, the problems of the recent war and life in tropical 

 places have brought about a renaissance in parasitology, which has re- 

 sulted in considerable new knowledge of the vitamin requirements of a 

 number of parasitic and vector invertebrates. 



Aside from the purely academic, commercial, and medical reasons for 

 inquiry into invertebrate nutrition, an increasing awareness of the benefits 

 to be derived from a study of comparative biochemistry seems likely to 

 bring about even greater interest in this field. We have already con- 

 sidered one such topic — Cowgill's application of comparative requirements 

 in assessing human vitamin requirements (p. 246). The challenge for 

 investigation in comparative biochemistry is very great. In many common 

 phyla (porifera, coelenterata, echinodermata, annelida) literally nothing 

 is known about vitamin requirements (or indeed nutritional require- 

 ments) . Still greater is the challenge, because up to the time of this 

 writing, no animal had as yet been reared and bred on a chemically 

 defined diet. In view of these considerations there are many limitations to 

 anything resembling a thorough review of invertebrate B vitamin require- 

 ments, and as to these limitations we are helpless. 



