DISEASES OF MARINE FISHES
23
fourth of all fish examined carried cysts beneath the peritoneum or in
the mesenteries.
Another species of the same genus, (r. anomala (Moniez), was
reported earlier (Weissenberg, 1913, 1921b) from European sticklebacks, Gnsterosteus aculeatus L. and Pungitius pungitius (L.). Hypertrophy of connective-tissue cells, resulting in thick-walled cysts up to
4 mm in diameter, occurred externally and internally. Kudo (1924)
and others described deformation of the host’s body as a result of
intensive G. anomala infection. The parasite has been reported as a
cause of mass mortality in sticklebacks from the White Sea (Dogie1
et al., 1958).
Still another species, Glugea punctifera Thelohan, is a serious intramuscular parasite of mintai, Theragra chalcograrnrna, from the Okhotsk
and Japan Seas (Akhmerov, 1951). Cod from the Okhotsk Sea were
also infected with this Glugea.
The microsporidean Nosema lophii (Doflein) produces large tumorlike cysts in the central nervous system of the goosefish or angler-fish,
Lophius piscatorius L. Parasitization results in extensive hypertrophy
of host ganglion cells as the cyst develops, producing dark grape-like
enlargements on the nerves. Weissenberg (1909, 1911a, 1911b, 1911c)
found abundant infections at Naples; the parasite has also been
reported from England and France.
Another microsporidean, Plistophora macrozoarcidis Nigrelli, is an
important parasite of the ocean pout, Macrozoarces aniericanus (Bloch
and Schneider). Extensive tumor-like intramuscular cysts, often
several centimewrs in diameter (Fig. 6), seriously reduce the marketability and utilization of this fish in the United States. Appearance of
fillets containing parasite cysts on the market during 1943-44 was
responsible in part for curtailment of a developing fishery for Macrozoarces, and in a few years led to complete disappearance of the species
as a food fish in the United States (Fischthal, 1944; Sandholzer et al.,
1945). Recent interest in reviving the fishery seems contingent on
development of a suitable method of eliminating parasitized fish from
processing procedures.
Plistophora cysts can often be recognized by conspicuous bulges
on the body of the host. The lesions are usually exposed during
filleting, and a pus-like exudate of spores and tissue debris occurs
when such areas are cut, Life cycle stages have been described by
Nigrelli (1946). No ulceration has been seen. so the method of spore
liberation has been postulated as death and decay of the host. The
massive involvement of individual fish suggests sporulation in situ.
Repeated auto-infection is possible in some species of Microsporidea,
23
fourth of all fish examined carried cysts beneath the peritoneum or in
the mesenteries.
Another species of the same genus, (r. anomala (Moniez), was
reported earlier (Weissenberg, 1913, 1921b) from European sticklebacks, Gnsterosteus aculeatus L. and Pungitius pungitius (L.). Hypertrophy of connective-tissue cells, resulting in thick-walled cysts up to
4 mm in diameter, occurred externally and internally. Kudo (1924)
and others described deformation of the host’s body as a result of
intensive G. anomala infection. The parasite has been reported as a
cause of mass mortality in sticklebacks from the White Sea (Dogie1
et al., 1958).
Still another species, Glugea punctifera Thelohan, is a serious intramuscular parasite of mintai, Theragra chalcograrnrna, from the Okhotsk
and Japan Seas (Akhmerov, 1951). Cod from the Okhotsk Sea were
also infected with this Glugea.
The microsporidean Nosema lophii (Doflein) produces large tumorlike cysts in the central nervous system of the goosefish or angler-fish,
Lophius piscatorius L. Parasitization results in extensive hypertrophy
of host ganglion cells as the cyst develops, producing dark grape-like
enlargements on the nerves. Weissenberg (1909, 1911a, 1911b, 1911c)
found abundant infections at Naples; the parasite has also been
reported from England and France.
Another microsporidean, Plistophora macrozoarcidis Nigrelli, is an
important parasite of the ocean pout, Macrozoarces aniericanus (Bloch
and Schneider). Extensive tumor-like intramuscular cysts, often
several centimewrs in diameter (Fig. 6), seriously reduce the marketability and utilization of this fish in the United States. Appearance of
fillets containing parasite cysts on the market during 1943-44 was
responsible in part for curtailment of a developing fishery for Macrozoarces, and in a few years led to complete disappearance of the species
as a food fish in the United States (Fischthal, 1944; Sandholzer et al.,
1945). Recent interest in reviving the fishery seems contingent on
development of a suitable method of eliminating parasitized fish from
processing procedures.
Plistophora cysts can often be recognized by conspicuous bulges
on the body of the host. The lesions are usually exposed during
filleting, and a pus-like exudate of spores and tissue debris occurs
when such areas are cut, Life cycle stages have been described by
Nigrelli (1946). No ulceration has been seen. so the method of spore
liberation has been postulated as death and decay of the host. The
massive involvement of individual fish suggests sporulation in situ.
Repeated auto-infection is possible in some species of Microsporidea,