Alteration in protein carbohydrate complexes in plasma of freshwater gastropod snail, Lymnaea luteola, challenged with foreign tissue implant.

Levels of protein bound hexose, hexosamine and proteins in ethanol precipitate of the body fluid and protein bound hexose and proteins in the perchloric acid filtrate of the body fluid of the snail L. luteola which received a xenoplastic implant in its cephalopedal sinus, are determined. The significant increase in protein bound hexose in the ethanol precipitate of bodyfluid in recipient snail as compared to sham operated and control snails is interesting. The results are discussed in the light of what is known about glycoproteins and their role in invertebrate immunity.

Failure of irradiated Echinostoma audyi and Hypoderaeum dingeri to sensitize Lymnaea rubiginosa snails.

Attempts to induce acquired resistance in Lymnaea rubiginosa snails against the echinostomes Echinostoma audyi and Hypoderaeum dingeri by means of irradiated miracidia were unsuccessful, although Lie and coworkers using similar methods had recently sensitized Biomphalaria glabrata against Echinostoma lindoense (1975a). In contrast to the B. glabrata-E. lindoense system, in Lymnaea rubiginosa the amebocytic response to irradiated parasites was slow: irradiated E. audyi sporocysts were encapsulated 15 to 28 days and H. dingeri sporocysts 20 to 27 days postexposure. No obvious enlargement of the amebocyte-producing organ was seen. No resistance was demonstrable to subsequent homologous challenge. Development of acquired resistance to a trematode infection in snails may be related to the speed with which the snails destroy the irradiated sporocysts.