DISEASES OF MARINE FISHES
53
in marine teleosts and elasmobranchs to injected viral and bacterial
antigens. Lemon shark, Negaprion brevirostris (Poey), produced
significant titers of hemagglutination-inhibition antibodies with a high
degree of specificity in response to injected influenza virus. Lower
titers and less specificity were found in similar studies of the margate,
Haemulon album Cuvier. A very low degree of immunologic reactivity
was evident in the sea lamprey, Petromyzon murinus L. Goiicharov
(1962) hyperimmunized several cyprinid species a t 15 to 25°C with
killed Pseudomonas fluorescens and other bacteria, and produced agglutinin titers as high as 10 240. The agglutinins were specific, and the
reaction was temperature-dependent, since antibodies were not formed
at 6 to 7 O C . Krantz et al. (1963, 1964), in research oriented toward
control of hatchery diseases through immunization, reported significant
antibody response in trout to killed bacteria injected with adjuvant.
Maximum agglutinin titers were reached 3 to 4 months after injection.
Fish immunized with a vaccine of formalin-killed Aeromonus
salmonicida, the etiological agent of furunculosis, were protected during
challenge with viable pathogens, but untreated controls were not.
The authors pointed out, however, that augmented natural defense
mechanisms often cannot prevent infection when the fish is confronted
by severe physiological or environmental stresses. Post (1963) had
used a similar immunization method to achieve moderate protection
of rainbow trout, Salmo gairdneri, against Aeromonas hydrophila.
Spence et al. (1965) were able to produce appreciable antibody titers
in rainbow trout immunized against Aeromonas salmonicida; the antiserum so produced provided passive protection of juvenile salmon when
injected intraperitoneally. Several authors, including Post (1962) have
suggested oral immunization as a practical mass prophylactic method,
but evidence is conflicting. Duff (1942) reported resistance of trout to
furunculosis after feeding an oral vaccine of killed Aeromonas salmonicida, and Ross and Klontz (1965) found increased survival of rainbow
trout after oral immunization against ( ( redmouth disease.’’ Snieszko
and Friddle (1949), however, were unable to demonstrate protection of
young brook trout against furunculosis by oral immunization and
Spence et al. (1965) found that oral vaccine did not protect salmon
exposed to Aeromonas salmonicida.
Poikilothermic vertebrates such as fish are excellent subjects for
basic studies of immune responses. Allen and McDaniel (1937), Pliszka
(1939), Cushing (1942) and Bisset (l946,1948a, 1948b) have summarized
effects of temperature on antibody production, and have demonstrated
that production was minimal below 10°C. Sindermann and Honey
(1964) found that certain natural heteroagglutinins of winter skates,
53
in marine teleosts and elasmobranchs to injected viral and bacterial
antigens. Lemon shark, Negaprion brevirostris (Poey), produced
significant titers of hemagglutination-inhibition antibodies with a high
degree of specificity in response to injected influenza virus. Lower
titers and less specificity were found in similar studies of the margate,
Haemulon album Cuvier. A very low degree of immunologic reactivity
was evident in the sea lamprey, Petromyzon murinus L. Goiicharov
(1962) hyperimmunized several cyprinid species a t 15 to 25°C with
killed Pseudomonas fluorescens and other bacteria, and produced agglutinin titers as high as 10 240. The agglutinins were specific, and the
reaction was temperature-dependent, since antibodies were not formed
at 6 to 7 O C . Krantz et al. (1963, 1964), in research oriented toward
control of hatchery diseases through immunization, reported significant
antibody response in trout to killed bacteria injected with adjuvant.
Maximum agglutinin titers were reached 3 to 4 months after injection.
Fish immunized with a vaccine of formalin-killed Aeromonus
salmonicida, the etiological agent of furunculosis, were protected during
challenge with viable pathogens, but untreated controls were not.
The authors pointed out, however, that augmented natural defense
mechanisms often cannot prevent infection when the fish is confronted
by severe physiological or environmental stresses. Post (1963) had
used a similar immunization method to achieve moderate protection
of rainbow trout, Salmo gairdneri, against Aeromonas hydrophila.
Spence et al. (1965) were able to produce appreciable antibody titers
in rainbow trout immunized against Aeromonas salmonicida; the antiserum so produced provided passive protection of juvenile salmon when
injected intraperitoneally. Several authors, including Post (1962) have
suggested oral immunization as a practical mass prophylactic method,
but evidence is conflicting. Duff (1942) reported resistance of trout to
furunculosis after feeding an oral vaccine of killed Aeromonas salmonicida, and Ross and Klontz (1965) found increased survival of rainbow
trout after oral immunization against ( ( redmouth disease.’’ Snieszko
and Friddle (1949), however, were unable to demonstrate protection of
young brook trout against furunculosis by oral immunization and
Spence et al. (1965) found that oral vaccine did not protect salmon
exposed to Aeromonas salmonicida.
Poikilothermic vertebrates such as fish are excellent subjects for
basic studies of immune responses. Allen and McDaniel (1937), Pliszka
(1939), Cushing (1942) and Bisset (l946,1948a, 1948b) have summarized
effects of temperature on antibody production, and have demonstrated
that production was minimal below 10°C. Sindermann and Honey
(1964) found that certain natural heteroagglutinins of winter skates,