206
MARINE MOLLUSCS AS HOSTS FOR SYMBIOSES
Ostrea edulis, lives and is thus different from the American species, B.
cuculus, in Crassostrea virginica, which is found in more landlocked
estuarine waters of comparatively low salinities.
Physiology. The histochemical studies by James et al. (1966),
together with electron microscope studies, have revealed that the dense
cytoplasmic areas of the syncytial tegument of Bucephalus haimeanus
sporocysts include a neutral mucopolysaccharide which may be the
precursor of the acid mucopolysaccharide found in the sparse reticulate
cytoplasmic areas of the same zone and on the sporocyst surface.
James et al. have also stated :
Although there is no evidence of pinocytosis (on the outer surfaye of the
external syncytial tegument) in the electron-micrographs, the peculiar
distribution of glucose, glycogen, fatty acids and neutral lipids, in the
tegument and subtegument, suggests that these substances pass through
the outer plasma membrane and the sparse reticulate cytoplasm of the
middle region to accumulate above the inner plasma membrane of the
tegument. They then pass through this and the basement membrane into
the extensions of the giant somatic cells, which form such a conspicuous part
of the subtegument.
This represents the first published interpretation of the mechanism by
which sporocysts acquire their nutrients and perhaps other materials
as based on electron microscope studies.
Pathology. Although the sporocysts of B. hairneanus are known to
infiltrate practically every organ in the body of its molluscan host, a
detailed histopathological study has not yet been made. Its effect on
the mollusc has not been investigated other than that this parasite is
known to cause parasitic castration. It could be noted that Millar
(1963) has reported that a significant percentage of Ostrea lutraria
shipped to Great Britain from Faveaux Strait, New Zealand, parasitized
by an unidentified bucephalid, was killed.
2. Bucephalus cucuZus McCrady, 1873. (Figs. 112-1 14)
(Superorder Anepitheliocystidia; order Strigeatoidea; suborder Azygiata;
What is generally believed to be the American species of Bucephalus,
B. cuculus, was originally found and named by McCrady (1873) from
the American oyster, Crassostrea virginica, in Charleston, South
Carolina, although his description was far from adequate by modern
standards. Since then, what is presumed to be the same species has
been reported by Nelson (1890, 1903, 1915) in C. virginica from New
Jersey, and Glaser (1904) and others from the same oyster at Cameron,
superfamily Bucephaloidea; family Bucephalidae)
MARINE MOLLUSCS AS HOSTS FOR SYMBIOSES
Ostrea edulis, lives and is thus different from the American species, B.
cuculus, in Crassostrea virginica, which is found in more landlocked
estuarine waters of comparatively low salinities.
Physiology. The histochemical studies by James et al. (1966),
together with electron microscope studies, have revealed that the dense
cytoplasmic areas of the syncytial tegument of Bucephalus haimeanus
sporocysts include a neutral mucopolysaccharide which may be the
precursor of the acid mucopolysaccharide found in the sparse reticulate
cytoplasmic areas of the same zone and on the sporocyst surface.
James et al. have also stated :
Although there is no evidence of pinocytosis (on the outer surfaye of the
external syncytial tegument) in the electron-micrographs, the peculiar
distribution of glucose, glycogen, fatty acids and neutral lipids, in the
tegument and subtegument, suggests that these substances pass through
the outer plasma membrane and the sparse reticulate cytoplasm of the
middle region to accumulate above the inner plasma membrane of the
tegument. They then pass through this and the basement membrane into
the extensions of the giant somatic cells, which form such a conspicuous part
of the subtegument.
This represents the first published interpretation of the mechanism by
which sporocysts acquire their nutrients and perhaps other materials
as based on electron microscope studies.
Pathology. Although the sporocysts of B. hairneanus are known to
infiltrate practically every organ in the body of its molluscan host, a
detailed histopathological study has not yet been made. Its effect on
the mollusc has not been investigated other than that this parasite is
known to cause parasitic castration. It could be noted that Millar
(1963) has reported that a significant percentage of Ostrea lutraria
shipped to Great Britain from Faveaux Strait, New Zealand, parasitized
by an unidentified bucephalid, was killed.
2. Bucephalus cucuZus McCrady, 1873. (Figs. 112-1 14)
(Superorder Anepitheliocystidia; order Strigeatoidea; suborder Azygiata;
What is generally believed to be the American species of Bucephalus,
B. cuculus, was originally found and named by McCrady (1873) from
the American oyster, Crassostrea virginica, in Charleston, South
Carolina, although his description was far from adequate by modern
standards. Since then, what is presumed to be the same species has
been reported by Nelson (1890, 1903, 1915) in C. virginica from New
Jersey, and Glaser (1904) and others from the same oyster at Cameron,
superfamily Bucephaloidea; family Bucephalidae)