220
MARINE MOLLUSCS AS HOSTS FOR SYMBIOSES
Odhner ”, a parasite in the gall-bladder of the common sheld duck,
Vulpanser tadorna, and other shore ducks, including A ythya ferina,
Clangula hyemalis, Somateria mollissima and S . spectabilis, in Europe.
Other information. Nothing else is known about C. fulbrighti except
that Hutton has reported that dual infections in Cardium edule with
this cercaria and Bucephalus haimeanus and triple infections with C .
fulbrighti, B. huimeanus and C . cambrensis do occur.
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c
0 3
c
FIG. 129. Development and subsequent degeneration of the tail of Cercaricz (Gymnophallus) fulbrighti. These changes occur within the brood chamber of the sporocyst.
The escaping cercaria is tailless. (Redrawn after Hutton, 1962.)
1 1. Metacercaria (Gymnophallus) scrivenensis sp. inq. Lebour, 191 1.
(Superorder Anepitheliocystidia; order Strigeatoidea; suborder Azygiata;
This Gymnophallus metacercaria was described by Lebour (1911)
as a cercaria in a single specimen of Tapes pullastra collected from
Loch Striven, Firth of Clyde, Scotland. She found the parasite free
between the mantle and the shell without an enveloping gelatinous
cyst as in the case of G. rnegalocoela or G. margaritarum. From what is
known about the life cycle pattern among gymnophallid trematodes,
(Fig. 130)
superfamily Fellodistomatoidea; family Fellodistomatidae)