12. IMMUNOLOGY OF FISH
491
them to the conclusion that lampreys have the most primitive such
responses studied in contrast to the more primitive Pacific hagfish,
Eptatretus stoutii, where a number of immunological reactions were not
detected.
More recently, however, Hildemann has pointed out that it seems
improbable that a physiological system as complex as that of adaptive
immunity would have evolved so rapidly (1966, p. 240) between the
phylogenetic stages represented by these two forms and, further, Hildemann and Thoenes (1969) have shown that hagfish “animal husbandry”
has important consequences for results obtained. Their work demonstrates in considerable detail that hagfish can reject transplants in the
same manner, including immunological memory, as higher forms, and
also produce circulating antibodies against sheep erythrocytes. Further,
Evans and Hildemann and their associates (1969) have shown that hagfish are also capable of producing bactericidins (although the latter have
not yet been characterized as necessarily being antibodies ) , Hildemann
and Thoenes conclude that a “closer look at thymus-lymphoid cellimmunoglobulin relationships” among lower vertebrates is needed. Since
invertebrates have so far not been demonstrated to produce antibodies
(cf. Cushing, 1967), the origins of adaptive immunity remain to be
discovered, The work of Cooper (1968) on earthworm transplants, of
Stevens on induced bactericidins in insects (1967), of Bang on induced
lysins in sipunculids (1967), of Seaman and Robert on cockroaches
(1968), and of Evans et al. on induced bactericidins in spiny lobsters
(196813, and 1969a) and sipunculids (1969b) offer exciting material for
further research in this area.
VII. FINAL CONSIDERATIONS
This section considers briefly some relevant matters not covered
above. The first is the point, which should not be overlooked, that the
immunological mechanism obviously was evolved as a defense against
parasitic infection. The reader is referred to Sindermann’s excellent
review of the parasites of marine fishes (1966) and also to Davis’s book
entitled “Culture and Diseases of Game Fishes” ( 1967). The relative
newness of the relation between the immunology and parasitology of
fishes is indicated in that, while the first publication has an extensive
section and other comments dealing with immunity, the second, although
an authoritative treatise, does not even have subject references to this
field in the index.
491
them to the conclusion that lampreys have the most primitive such
responses studied in contrast to the more primitive Pacific hagfish,
Eptatretus stoutii, where a number of immunological reactions were not
detected.
More recently, however, Hildemann has pointed out that it seems
improbable that a physiological system as complex as that of adaptive
immunity would have evolved so rapidly (1966, p. 240) between the
phylogenetic stages represented by these two forms and, further, Hildemann and Thoenes (1969) have shown that hagfish “animal husbandry”
has important consequences for results obtained. Their work demonstrates in considerable detail that hagfish can reject transplants in the
same manner, including immunological memory, as higher forms, and
also produce circulating antibodies against sheep erythrocytes. Further,
Evans and Hildemann and their associates (1969) have shown that hagfish are also capable of producing bactericidins (although the latter have
not yet been characterized as necessarily being antibodies ) , Hildemann
and Thoenes conclude that a “closer look at thymus-lymphoid cellimmunoglobulin relationships” among lower vertebrates is needed. Since
invertebrates have so far not been demonstrated to produce antibodies
(cf. Cushing, 1967), the origins of adaptive immunity remain to be
discovered, The work of Cooper (1968) on earthworm transplants, of
Stevens on induced bactericidins in insects (1967), of Bang on induced
lysins in sipunculids (1967), of Seaman and Robert on cockroaches
(1968), and of Evans et al. on induced bactericidins in spiny lobsters
(196813, and 1969a) and sipunculids (1969b) offer exciting material for
further research in this area.
VII. FINAL CONSIDERATIONS
This section considers briefly some relevant matters not covered
above. The first is the point, which should not be overlooked, that the
immunological mechanism obviously was evolved as a defense against
parasitic infection. The reader is referred to Sindermann’s excellent
review of the parasites of marine fishes (1966) and also to Davis’s book
entitled “Culture and Diseases of Game Fishes” ( 1967). The relative
newness of the relation between the immunology and parasitology of
fishes is indicated in that, while the first publication has an extensive
section and other comments dealing with immunity, the second, although
an authoritative treatise, does not even have subject references to this
field in the index.