CHAPTER 5
PARASITES OF COMMERCIALLY IMPORTANT
MARINE MOLLUSCS
THE PHYLUM PROTOZOA
What is a commercially important marine mollusc? Presumably
the answer is that it is one which is harvested commercially and used
on a large scale as a food source. Thus on the east coast of the United
States, the American oyster, Crassostrea virginica, the soft clam, Mya
arenuria, the quahaug, Mercenaria mercenaria, the bay scallop, Aequipecten irradians, and the surf clam, Xpisula solidissima, would certainly
qualify. From Virginia to Texas, Mercenaria campechiensis, the
southern quahaug, is harvested in large quantities. Similarly, along the
Atlantic coast of Canada, Crassostrea virginica would be considered the
major marine economic mollusc. Along the Pacific coast of the United
States, the native Pacific oyster, Ostrea lurida, the Japanese oyster,
Crassostrea gigas, the soft clam, Mya arenaria, the so-called Japanese
little neck clam, Tapes semidecussata (= Venerupis semidecussata, V .
philippinarum, Paphia philippinarum, Tapes japonica), the razor clam,
Siliqua patula, the pismo clam, Tivela stultorum, a number of species
of abalone, Haliotis spp., as well as several other species of pelecypods
would qualify. In British and northern European waters, the European
oyster, Ostrea edulis, the cockles, Cardium spp., the mussel, Mytilus
edulis, and the buckie, Buccinum undatum, are harvested commercially,
while in the Mediterranean, conchs of the genus Busycon, the pelecypods
Tapes decussatus, Mytilus galloprovincialis, as well as other molluscs
are of commercial importance. In the Far East, commercial shellfisheries in Japan are primarily limited to the Japanese oyster, Crassostrea gigas, and the clam, Tapes semidecussata, although other species
are also harvested.
As one travels throughout the world and investigates the species of
molluscs incorporated in the diets of various ethnic groups, a number of
species of marine molluscs must definitely be considered to be of
economic importance since not only are these frequently used as food,
but are regularly found in markets. Among the Japanese and Chinese,
for example, various species of squids and octopi form a part of the
136
PARASITES OF COMMERCIALLY IMPORTANT
MARINE MOLLUSCS
THE PHYLUM PROTOZOA
What is a commercially important marine mollusc? Presumably
the answer is that it is one which is harvested commercially and used
on a large scale as a food source. Thus on the east coast of the United
States, the American oyster, Crassostrea virginica, the soft clam, Mya
arenuria, the quahaug, Mercenaria mercenaria, the bay scallop, Aequipecten irradians, and the surf clam, Xpisula solidissima, would certainly
qualify. From Virginia to Texas, Mercenaria campechiensis, the
southern quahaug, is harvested in large quantities. Similarly, along the
Atlantic coast of Canada, Crassostrea virginica would be considered the
major marine economic mollusc. Along the Pacific coast of the United
States, the native Pacific oyster, Ostrea lurida, the Japanese oyster,
Crassostrea gigas, the soft clam, Mya arenaria, the so-called Japanese
little neck clam, Tapes semidecussata (= Venerupis semidecussata, V .
philippinarum, Paphia philippinarum, Tapes japonica), the razor clam,
Siliqua patula, the pismo clam, Tivela stultorum, a number of species
of abalone, Haliotis spp., as well as several other species of pelecypods
would qualify. In British and northern European waters, the European
oyster, Ostrea edulis, the cockles, Cardium spp., the mussel, Mytilus
edulis, and the buckie, Buccinum undatum, are harvested commercially,
while in the Mediterranean, conchs of the genus Busycon, the pelecypods
Tapes decussatus, Mytilus galloprovincialis, as well as other molluscs
are of commercial importance. In the Far East, commercial shellfisheries in Japan are primarily limited to the Japanese oyster, Crassostrea gigas, and the clam, Tapes semidecussata, although other species
are also harvested.
As one travels throughout the world and investigates the species of
molluscs incorporated in the diets of various ethnic groups, a number of
species of marine molluscs must definitely be considered to be of
economic importance since not only are these frequently used as food,
but are regularly found in markets. Among the Japanese and Chinese,
for example, various species of squids and octopi form a part of the
136