[The evaluation of snail host-trematode parasite trophic relationships using stable isotope analysis].

Stable isotope ratios of carbon (13C/12C, δ13C) and nitrogen (15N/14N, δ15N) in snail-host tissue (the foot and hepatopancreas) and trematode parasites on two stages of their life cycle were analyzed. Trophic structure in co-occurring trematode larvae was examined in the following species: five species of cercariae (Echinoparyphium recurvatum, Hypodereum conoideum, Plagiorchis mutationis, Diplostomum chromatophorum and D. volvens) and two species of metacercariae (Cotylurus cornutus and Echinoparyphium recurvatum) within two closely related snail hosts Lymnaea stagnalis and L.

[Activity of detoxifying and antioxidant enzymes in the pond snail Lymnaea stagnalis (gastropoda: pulmonata) during invasion by trematode cercariae].

A comparative analysis of changes of activities of detoxifying and antioxidant enzymes was carried out in the body homogenate of the pond snail Lymnaea stagnalis. Juvenile snails with the shell size of 4-6 mm were infested with cercariae of one (Echinoparyphium aconiatum or E. recurvatum or Moliniella anceps) or two (E.

[An activity of nonspecific esterases in homogenates of Lymnaea stagnalis and Lymnaea tumida snails (Gastropoda: Pulmonata) infected by trematode cercariae Echinoparyphium aconiatum and Moliniella anceps (Echinostomatidae)].

The comparative analysis of esterase changes in homogenates of the snails Lymnaea stagnalis and L. tumida bodies was carried out. Juvenile snails with shell size 2 mm, 3-4 mm, 5-6 mm and 7-8 mm were exposed to cercariae of the trematodes Echinoparyphium aconiatum and/or Moliniella anceps.

[The effect of trematodes on the cellular immunity of the dragonfly Aeschna grandis (Odonata) larvae].

The high percent of the infestation by the trematodes of the families Plagiorchidae and Prosthogonimidae is recorded in the dragonfly Aeschna grandis larvae of the last stage. About 30% of the trematode cysts were melanized. It is established, that the parasitising of the trematodes do not effects on the process of the incapsulation of foreign bodies, but it suppresses partly the formation of oxygen free radicals and phenoloxidase activity in the haemocytes of dragonfly larvae.

[New data on Cyathocotyle bushiensis (Trematoda: Cyathocotylidae)].

Metacercariae of Cyathocotyle bushiensis Khan, 1962 (Digenea) were found in populations of seven species of gastropod snails collected from lakes and rivers in the south of West Siberia (Russia). This is the first record of C. bushiensis in Russia.