94
MARINE MOLLUSCS AS HOSTS FOR SYMBIOSES
fluence of the ambient sea water must be taken into consideration.
From the information presented above, it is obvious that a great deal
remains to be learned about amino acid uptake by parasites and
These data indicate that taurine is only present in marine species.
(After Allen, 1961b.)
TABLE X. TAURINE CONTENT IN VARIOUS MOLLUSCS
Species
Environment
Taurine
Gastropoda
Lymnaea paluatrk
Marisa cornwlrietk
Pomucea bridgesi
Rumina decollata
Otala lactea
Mesodon thyroidua
Bulimulua alternatua
Murex fulvescens
Littorina irrorata
Oliva sayana
Polinices duplicata
Busycon perversum
Siphonaria Eineolata
Fmciolaria distans
Thais haemmtoma haysae
Anodonta grandis
Quadrula quadrula
Lampsilia sp.
Elliptio sp.
Rangia cuneata
Brachidontea recurvua
Crmsostrea virginica
D o m variabilis
Venus mercenaria
Dosinia discus
Area ineongrua
Area campeehiensis
Noetia ponderosa
Loliguncula brevis
Pelecypoda
Cephalopoda
Fresh water
Fresh water
Fresh water
Terrestrial
Terrestrial
Terrestrial
Terrestrial
Marine
Marine
Marine
Marine
Marine
Marine
Marine
Marine
Fresh water
Fresh water
Fresh water
Fresh water
Brackish-fresh water
Brackish-marine
Brackish-marine
Marine
Marine
Marine
Marine
Marine
Marine
Marine
mutualists. Direct evidence of uptake is still wanting. As a speculation,
it would be interesting to determine whether the decarboxylation product
taurine, which has been identified from nearly every marine mollusc
examined (Table X), is taken up by their parasites since its presence