Endobiotic Ciliates from the Rumen of the European Bison Bison Bonasus (Linnaeus, 1758) from the Vologda Oblast of Russia.

The fauna of endobiotic ciliates of the rumen of the European bison Bison bonasus from the Vologda oblast of Russia was investigated. In the studied bisons, 12 species of trichostomatids (Trichostomatia, Litostomatea) were found, ten of which were from the family Ophryoscolecidae and two species were from the family Isotrichidae. A high similarity of ciliate faunas in the rumen of different bison individuals in the studied population was noted. A comparative analysis of data on the species diversity and number of endobiotic ciliates in the rumen of various representatives of the genus Bison from different habitats was carried out.

[The study of Balantidium Helenae Bezzenberger, 1904 (Litostomatea, Trichostomatia) inhabiting the intestines of the frog Rana temporaria Linnaeus, 1758, in optical and electron microscopes].

The structure of the ciliate Balantidium helenae Bezzenberger, 1904 was investigated with the use of optical and electron microscopy. It was demonstrated that, together with the basic dimensional characteristics, main distinguishing features of the studied species include the following characters: the presence of a pointed prominence on the posterior margin of the cell; the presence of elongated cilia on the left margin of the vestibulum; and different shape and size of cortical ridges. Two morphologically different types of electron-dense bodies (supposedly hydrogenosoms) and also endobiotic bacteria were also found in the cytoplasm of B. helenae.

[Ciliates from the intestine of Yakut horse (Equus caballus)].

Endobiotic ciliates of native Yakut horse are investigated. 57 ciliate species have been found. From 17 up to 43 species of ciliates have been revealed in each host specimen. The specimens of Alloiozona trizona Hsiung, 1930 and Triadinium caudatum Fiorentini, 1890 were present in 100 % of the horses. The endemic genus and species of allantosomides, Strelkowella urunbasiensis Kornilova, 2004, has been found in 11 horses. Allantoxena japonensis (Imai, 1979) and Cycloposthium ishikawai Gassovsky, 1919 being recorded previously in Japan only were found for the first time in Russia. The species Cycloposthium ponomarevi Kornilova, 2001 peculiar to the Turkmenistan koulan has been found in the Yakut horses.

[The use of endobiotic ciliates from old collections in transmission electron microscopic investigations].

The opportunity of the use of formalin-fixed endobiotic ciliates from old collections in transmission electron microscopic investigations (TEM) has been studied. Ciliates from the following species were examined: Ditoxum funinucleum Gassovsky, 1919 from the hindgut of Equus hemionus kulan Groves et Mazak, 1967 preserved in a collection during 19 years, Blepharoprosthium pireum Bundle, 1895 and Cochliatoxum periachtum Gassovsky, 1919 from the hindgut of the Yakut horse Equus caballus L. stored during 1.5 years, and Triplumaria heterofasciculata Timoshenko et Imai, 1995 from faeces of the Asian elephant Elephas maximus L. stored during 2.5 years. It is shown, that the main taxonomically important characters of the cortex ultrastructure, ciliature, and internal fibril structure of the cell of Trichostomatia keep well during a long-term storage in formalin.