[Development of monogeneans from the family Tetraonchidae under experimental conditions].

Experimental data on the development of the Tetraonchus borealis larvae and species of the genus Salmonchus are given for the first time. The experiments was carried out in field conditions, in the estuary of the Shegnanda river (Baikal Lake basin), during 25 days. It was established that temperatures from 15 to 22 degrees C are favorable for the culture of the Salmonchus eggs followed by the emergence of larvae at eighth or ninth day. At the same time, T. borealis larvae need in lower temperatures, from 15 to 17 degrees C for their development. Detailed descriptions of eggs and larvae of the Tetraonchidae species under are given.

[Study of the monogenean family Tetraonchidae Bychowsky, 1937 by the scanning electron microscopy].

Hitherto data on the morphology of Tetraonchidae and their eggs obtained with scanning electron microscopy (SEM) were absent in the literature. In the present paper results of SEM study of two genera of Tetraonchidae, Tetraonchus and Salmonchus, are given. Fine morphological traits of eggs, larvae, and definitive individuals of Tetraonchidae, as well as patterns of their attachment to host gill, were established for the first time. A deep penetration of the worms into the branchial epithelium of the host was shown.

[A description of the new species of Tetraonchus strelkowi sp.n. (Monogenea: Tetraonchidae) from gills of the lenok (Brachymastix lenok) from the Tola river (Mongolia) ]. / Opisanie novogo vida Tetraonchus strelkowi sp.n. (Monogenea: Tetraonchidae) s zhabr lenka (Brachymystax lenok) iz reki Tola (Mongoliia).

Tetraonchus strelkowi sp. n. described from gills of the lenok Brachymastix lenok from the Tola river (Mongolia) differs from T. roytmani by morphometric characteristics of the haptor and copulatory complex.

[First record of Tetraonchus awakurai (Monogenea: Tetraonchidae) on gills of a lenok Brachymystax tumensis in Primor'e]. / Pervaia nakhodka Tetraonchus awakurai (Monogenea: Tetraonchidae) na zhabrakh tuporylogo lenka--Brachymystax tumensis iz Primorskogo kraia.

Drawings, description and size characteristics are given for Tetraonchus awakurai, which is registered for the first time from Brachymystax tumensis in the Ussury river (Primorye). The T. awakurai from the Ussury river differs from the typical forms living in water reservoirs of Japan by the measurements of external and internal lengths of anchors and copulatory complex.