Heterophilic antigens and antibodies in fresh water and marine fish.

Reciprocal agglutination studies using reagents from six fresh water fish species indicated distinct patterns between the behaviour of carp, bullhead and pickerel erythrocytes, and those derived from bass and from sunfish in contrast to perch erythrocytes, which were unreactive in the presence of sera from other fish species. Each of these could be further differentiated from one another by reciprocal absorption experiments or by the use of unabsorbed or absorbed serum from human group O, A, B and AB individuals. In similar fashion, it could be shown that members of three marine fish species differed from one another in regard to agglutinogen content. These were the Conger eel, red hind and the toadfish. Absorption experiments also demonstrated the presence of a factor or factors common to the latter species, but absent in the brown bullhead.