12. IMMUNOLOGY OF FISH
489
by anti-H-like antibodies in the serum of Ictalurw nebubsus and eel
serum. The catfish agglutinins behave electrophoretically like human
?M, and in the ultracentrifuge they have light and heavy components,
both of which are inactivated by mercaptoethanol. Chuba (1968) has
found Forssman-like antigens in several other species of teleosts and
demonstrated that this antigen can be concentrated from goldfish,
Carassius auratus, aquarium water.
Vann (1966; Vann and Cushing, 1966) has studied the reaction of
Dolicos b i f l m lectin with the red cells of the California bonito, Sarda
chiliensis. [ Lectins are proteins extracted from plants and invertebrates
that are not antibodies but have the property of agglutinating erythrocytes; cf. Cushing et al. (1963) and Brown et al. (1968) for references,
especially to the work of Boyd’s group.] This lectin distinguishes between two kinds of individuals in this species, those that react positively (D-positive) and those that react negatively. Analysis of population data showed that D-positive fish were more frequent among larger
sized individuals in samples even when taken at the same time and
place. Unfortunately, it was not possible to maintain bonito in aquaria
so that the difference observed could not be followed during the growth
of individual fish. [de Ligny (1969) observed a similar phenomenon in
plaice, Hippoglossoides platessoides ( Fabr. ), of the North Sea. This
species appears to form subpopulations in that area and can be bred
in captivity so that it should provide especially favorable material for
further study,] A number of alternative explanations are considered by
Vann, ranging from the possibility of subpopulation differences to
changes in phenotype during the life of individual’ fish. This last
phenomenon has potentially related precedence in humans, chickens,
and fish (Sanders and Wright, 1962) and, most pertinently here, in the
Atlantic herring, Clupea harengus. This species has a blood group system
described as the C system (Sindermann, 1962) that consists of a single
positive antigen or its absence. Considerable variation was discovered
among herring samples with respect to the frequency of occurrence of
this antigen, and it looked as though it would be extremely useful in
subpopulation studies of this species. However, Ridgway ( 1968) has
discovered that the situation is complicated in that the number of Cnegative fish increase markedly in fish held at relatively high temperatures and has produced considerable evidence that herring erythrocytes
become inagglutinable by any reagents in fish living under temperature
stress, probably as a reflection of anemia and the relatively high output
of immature erythrocytes. Obviously, this and the observations of Vann
are among the “unusual deviations” that might be anticipated in the
study of fish (Cushing, 1964, p. 92) and are a warning that care must
489
by anti-H-like antibodies in the serum of Ictalurw nebubsus and eel
serum. The catfish agglutinins behave electrophoretically like human
?M, and in the ultracentrifuge they have light and heavy components,
both of which are inactivated by mercaptoethanol. Chuba (1968) has
found Forssman-like antigens in several other species of teleosts and
demonstrated that this antigen can be concentrated from goldfish,
Carassius auratus, aquarium water.
Vann (1966; Vann and Cushing, 1966) has studied the reaction of
Dolicos b i f l m lectin with the red cells of the California bonito, Sarda
chiliensis. [ Lectins are proteins extracted from plants and invertebrates
that are not antibodies but have the property of agglutinating erythrocytes; cf. Cushing et al. (1963) and Brown et al. (1968) for references,
especially to the work of Boyd’s group.] This lectin distinguishes between two kinds of individuals in this species, those that react positively (D-positive) and those that react negatively. Analysis of population data showed that D-positive fish were more frequent among larger
sized individuals in samples even when taken at the same time and
place. Unfortunately, it was not possible to maintain bonito in aquaria
so that the difference observed could not be followed during the growth
of individual fish. [de Ligny (1969) observed a similar phenomenon in
plaice, Hippoglossoides platessoides ( Fabr. ), of the North Sea. This
species appears to form subpopulations in that area and can be bred
in captivity so that it should provide especially favorable material for
further study,] A number of alternative explanations are considered by
Vann, ranging from the possibility of subpopulation differences to
changes in phenotype during the life of individual’ fish. This last
phenomenon has potentially related precedence in humans, chickens,
and fish (Sanders and Wright, 1962) and, most pertinently here, in the
Atlantic herring, Clupea harengus. This species has a blood group system
described as the C system (Sindermann, 1962) that consists of a single
positive antigen or its absence. Considerable variation was discovered
among herring samples with respect to the frequency of occurrence of
this antigen, and it looked as though it would be extremely useful in
subpopulation studies of this species. However, Ridgway ( 1968) has
discovered that the situation is complicated in that the number of Cnegative fish increase markedly in fish held at relatively high temperatures and has produced considerable evidence that herring erythrocytes
become inagglutinable by any reagents in fish living under temperature
stress, probably as a reflection of anemia and the relatively high output
of immature erythrocytes. Obviously, this and the observations of Vann
are among the “unusual deviations” that might be anticipated in the
study of fish (Cushing, 1964, p. 92) and are a warning that care must