390
REFERENCES
Page 214: Palombi’s (1924) claim that the sporocysts and cercariae in Tapes
and Cardium are the progenitor stages of the motacercaria in Mytilus is confusing in view of the recent report by Bowers and James (1967) (see note to
p. 218 below).
Page 218: Bowers and James (1967) consider that Cercaria cambrensis as
well as the larva believed by Jameson (1902) to be the immature form of
Lecithodendrium somateriae (= Qymnophalloides oedemia) (see p. 213) and the
larva designated as Cercaria marguritae by Lebour (1907, 1911) (see p. 213) are
all three identical to the larva of Meiogymnophallus minutus, a parasite of the
oyster catcher, Haematopwr ostralegus occidentalis. They have also proven
experimentally that the larvae of M . minutus in Cardium edule are not cercariae
within a sporocyst but metacercariae enveloped within a layer of host cells.
These metacercariae are infective to the oyster catcher. Consequently Bowers
and James are of the opinion that Jameson (1902), Lebour (1907) and Cole
(1938) did not find cercariae enclosed within sporocysts but metacercariae in
host tissue.
Recently Katkansky et al. (1967), as the result of examining
Crassostrea gigas parasitized by Mytilicola orientalis over a 2-year period
(1963-65) in Humboldt Bay, California, Yaquina Bay, Oregon, and Willapa
Bay, Oyster Bay and Hood Canal, Washington, have reported that no shortterm cyclic effects occur in regard to the incidence or intensity of parasitization
a t these sites.
Page 293:
Page 292:
Katkansky et al. (1967) have confirmed their finding that the
condition index of Crassostrea gigas is reduced when parasitized by Mytilicola
orientalis. In addition, they have reported that not only is the survival of
parasitized oysters unaffectod but there is little evidence of reduction of shell
growth.
References
Andrews, J. D. (1967). Interaction of two diseases of oysters in natural waters.
Proc. natn. Shelljish. Ass. 57, 38-49.
Bowers, E. A. and James, B. L. (1967). Studies on the morphology, ecology
and life-cycle of Meiogymnophallwr minutus (Cobbold, 1859), comb. nov.
(Trematoda: Gymnophallidae). Parasitology, 57, 281-300.
El Gindy, M. S. (1950). Doctoral dissertation. University of Michigan.
Kagan, I. G. arid Geiger, S. (1964). Susceptibilty of Australorbis glabratus to
reinfection with Schistosoma mansoni. J . Parasit. 50, 474-476.
Katkansky, S. C., Sparks, A. K. and Chew, K. K. (1967). Distribution and
effects of the endoparasitic copepod, Mytilicola orientalis, on the Pacific
oyster, Crassostrea gigas, on the Pacific coast. Proc. natn. Shellfish. Ass. 57,
50-68.
REFERENCES
Page 214: Palombi’s (1924) claim that the sporocysts and cercariae in Tapes
and Cardium are the progenitor stages of the motacercaria in Mytilus is confusing in view of the recent report by Bowers and James (1967) (see note to
p. 218 below).
Page 218: Bowers and James (1967) consider that Cercaria cambrensis as
well as the larva believed by Jameson (1902) to be the immature form of
Lecithodendrium somateriae (= Qymnophalloides oedemia) (see p. 213) and the
larva designated as Cercaria marguritae by Lebour (1907, 1911) (see p. 213) are
all three identical to the larva of Meiogymnophallus minutus, a parasite of the
oyster catcher, Haematopwr ostralegus occidentalis. They have also proven
experimentally that the larvae of M . minutus in Cardium edule are not cercariae
within a sporocyst but metacercariae enveloped within a layer of host cells.
These metacercariae are infective to the oyster catcher. Consequently Bowers
and James are of the opinion that Jameson (1902), Lebour (1907) and Cole
(1938) did not find cercariae enclosed within sporocysts but metacercariae in
host tissue.
Recently Katkansky et al. (1967), as the result of examining
Crassostrea gigas parasitized by Mytilicola orientalis over a 2-year period
(1963-65) in Humboldt Bay, California, Yaquina Bay, Oregon, and Willapa
Bay, Oyster Bay and Hood Canal, Washington, have reported that no shortterm cyclic effects occur in regard to the incidence or intensity of parasitization
a t these sites.
Page 293:
Page 292:
Katkansky et al. (1967) have confirmed their finding that the
condition index of Crassostrea gigas is reduced when parasitized by Mytilicola
orientalis. In addition, they have reported that not only is the survival of
parasitized oysters unaffectod but there is little evidence of reduction of shell
growth.
References
Andrews, J. D. (1967). Interaction of two diseases of oysters in natural waters.
Proc. natn. Shelljish. Ass. 57, 38-49.
Bowers, E. A. and James, B. L. (1967). Studies on the morphology, ecology
and life-cycle of Meiogymnophallwr minutus (Cobbold, 1859), comb. nov.
(Trematoda: Gymnophallidae). Parasitology, 57, 281-300.
El Gindy, M. S. (1950). Doctoral dissertation. University of Michigan.
Kagan, I. G. arid Geiger, S. (1964). Susceptibilty of Australorbis glabratus to
reinfection with Schistosoma mansoni. J . Parasit. 50, 474-476.
Katkansky, S. C., Sparks, A. K. and Chew, K. K. (1967). Distribution and
effects of the endoparasitic copepod, Mytilicola orientalis, on the Pacific
oyster, Crassostrea gigas, on the Pacific coast. Proc. natn. Shellfish. Ass. 57,
50-68.