5 . THE PHYLUM PROTOZOA
137
absence of statements concerning the public health significance of a
species indicates that nothing is known.
I. Phylum PROTOZOA
Although many species of protozoa are known to be parasites of
vertebrates and invertebrates, including marine animals, comparatively
few have been reported from commercially important marine molluscs.
Those which have been reported are briefly described and information
pertinent to these, including their life cycles, ecology, physiology,
pathology, and other types of information are given under appropriate
subheadings. The omission of specific subheadings indicates the lack
of information in these areas.
The classification employed herein for the higher taxa (order and
higher) is that recommended by Honigberg et al. (1964) who comprise
the Committee on Taxonomy and Taxonomic Problems of the Society
of Protozoologists. The familial designations used are those of Kudo
(1966) or, if not listed in that treatise, those of the original authors.
A. Subphylum SARCOMASTIGOPHOREA
Superclass Mastigophora
Although several species of flagellates have been reported as
symbionts, primarily as parasites, of molluscs (cf. Dujardin, 1841 ;
Kozloff, 1945; Reynolds, 1936)) as far as I can determine, only one
species, Hexamita injlata, has been reported as a parasite of commercially
important marine molluscs, specifically the oysters, Ostrea edulis and
Crassostrea virginica.
A second organism, originally named Trypanosoma balbianii, was
described by Certes (1882, 1883) from the stomach contents of oysters,
Ostrea edulis and Crassostrea angulata, taken a t Cancale and Marennes,
on the west coast of France. Certes believed that this “ spirillum-like ”
organism, which measures from 0.04 to 0.12 mm long x 0.001 to 0.003
mm thick, is related to one of the true trypanosomes, T . sanguinis, a
blood parasite of frogs, and also to the so-called “ Trypanosoma
eberthi ” described by S. Kent from the intestine of a duck. Certes’s
report was followed by that of Mobius (1883) who stated that he had
observed T . balbianii in 1869 in oysters taken a t Schleswig-Holstein,
Germany. I n the same year Ryder (1883), working at Woods Hole,
Massachusetts, noted that T . balbianii is probably similar to a spiral
organism which he had observed in the stomach of Crassostrea virginica
and named Spirillum ostrearum. According to Ryder, this organism is
not a flagellated protozoan but a schizomycetous fungus which can be
10.
137
absence of statements concerning the public health significance of a
species indicates that nothing is known.
I. Phylum PROTOZOA
Although many species of protozoa are known to be parasites of
vertebrates and invertebrates, including marine animals, comparatively
few have been reported from commercially important marine molluscs.
Those which have been reported are briefly described and information
pertinent to these, including their life cycles, ecology, physiology,
pathology, and other types of information are given under appropriate
subheadings. The omission of specific subheadings indicates the lack
of information in these areas.
The classification employed herein for the higher taxa (order and
higher) is that recommended by Honigberg et al. (1964) who comprise
the Committee on Taxonomy and Taxonomic Problems of the Society
of Protozoologists. The familial designations used are those of Kudo
(1966) or, if not listed in that treatise, those of the original authors.
A. Subphylum SARCOMASTIGOPHOREA
Superclass Mastigophora
Although several species of flagellates have been reported as
symbionts, primarily as parasites, of molluscs (cf. Dujardin, 1841 ;
Kozloff, 1945; Reynolds, 1936)) as far as I can determine, only one
species, Hexamita injlata, has been reported as a parasite of commercially
important marine molluscs, specifically the oysters, Ostrea edulis and
Crassostrea virginica.
A second organism, originally named Trypanosoma balbianii, was
described by Certes (1882, 1883) from the stomach contents of oysters,
Ostrea edulis and Crassostrea angulata, taken a t Cancale and Marennes,
on the west coast of France. Certes believed that this “ spirillum-like ”
organism, which measures from 0.04 to 0.12 mm long x 0.001 to 0.003
mm thick, is related to one of the true trypanosomes, T . sanguinis, a
blood parasite of frogs, and also to the so-called “ Trypanosoma
eberthi ” described by S. Kent from the intestine of a duck. Certes’s
report was followed by that of Mobius (1883) who stated that he had
observed T . balbianii in 1869 in oysters taken a t Schleswig-Holstein,
Germany. I n the same year Ryder (1883), working at Woods Hole,
Massachusetts, noted that T . balbianii is probably similar to a spiral
organism which he had observed in the stomach of Crassostrea virginica
and named Spirillum ostrearum. According to Ryder, this organism is
not a flagellated protozoan but a schizomycetous fungus which can be
10.