Gyrodactylus bohemicus sp. n. (Monogenea: Gyrodactylidae) from Oncorhynchus mykiss (Walbaum) and Salvelinus fontinalis (Mitchill) (Clupeiformes: Salmonidae) in Czechoslovakia.

Gyrodactylus bohemicus sp. n (Gyrodactylidae: Monogenea) is described from the fins, skin and gill filaments of Oncorhynchus mykiss (Walbaum) and Salvelinus fontinalis (Mitchill) (Clupeiformes: Salmonidae) from a trout farm in Czechoslovakia. G. bohemicus sp. n. is most closely related to G. thymalli Zitnan, 1960 and G. magnus Konovalov, 1967 in the shape of the anchors, the ventral and the dorsal bar, but can be distinguished from both these species by the shape of the marginal hook proper.

A new species of the genus Gyrodactylus Nordmann, 1832 (Monogenea) from Gobio gobio (L.).

Gyrodactylus dykovae sp. n. (Monogenea: Gyrodactylidae) is described from the fins of the freshwater fish, Gobio gobio (L.) (Cyprinidae), from the Rokytná River near Moravský Krumlov, Czechoslovakia. This species is most related to G. gobii Shulman, 1953 from which it differs by possessing more robust anchors with considerably larger shaft and by the morphology of the hook proper of marginal hooks.

Notes on Gyrodactylus gussevi Ling Mo-en, 1962 (Monogenea: Gyrodactylidae).

The authors describe a species which is strikingly similar to the species Gyrodactylus gussevi Ling Mo-en, 1962 on the basis of morphometrical evaluation of 6 gyrodactylid specimens found on the fins of Parasilurus asotus (L.) which was captured in the River Amur near Khabarovsk. Due to inaccurate and incomplete original description of G. gussevi, the authors have to determine this species only provisionally as G. gussevi. As a result of evident appurtenance to G. latus--complex, P. asotus seems to be the "wrong" host.

Two new species of the genus Gyrodactylus (Monogenea) from the fins of Leuciscus cephalus (L.).

Gyrodactylus kearni sp. n. and G. lamberti sp. n. (Monogenea: Gyrodactylidae) are described from the fins of the freshwater fish, Leuciscus cephalus (L.) (Cyprinidae), from the Rokytná River and Stepánovický Brook (basin of the River Danube), Czechoslovakia, G. kearni sp. n. is most related to G. leucisci Zitnan, 1964 in the shape and size of marginal hooks, but can be separated from it in the shape of anchors and ventral bar. G. lamberti sp. n. is most closely related to G. gobii Shulman, 1953 and G. truttae Glser, 1974 in the shape of the complex of anchors, but differs markedly from them in the shape of the hook proper of marginal hooks.

Paraquadriacanthus nasalis gen. et sp. n. (Monogenea: Ancyrocephalidae) from Clarias lazera Cuvier et Valenciennes.

Paraquadriacanthus nasalis gen. et sp. n. (Monogenea: Ancyrocephalidae) is described from the nasal cavities of the freshwater fish, Clarias lazera Cuvier et Valenciennes (Clariidae) from the River Nile near Cairo, Egypt.

Contribution to the knowledge of Gyrodactylus gurleyi Price, 1937 (Monogenea: Gyrodactylidae).

Gyrodactylus longoacuminatus Zitnan, 1964, forma minor sensu Ergens (1985) was identified as G. gurleyi Price, 1937. Morphological and metrical evaluations of the hard parts of opisthaptor of more than 200 specimens provided data on the variability of this parasite; Cyprinus carpio haematopterus represents its new host. Since the shape of the hard parts of opisthaptor of G. gurleyi is very similar to that of G. longoacuminatus, further detailed studies of the two species will be necessary, particularly of their reaction to the changes of environmental temperature.

A survey of the results of studies on Gyrodactylus katharineri Malmberg, 1964 (Gyrodactylidae: Monogenea).

The hitherto obtained information on Gyrodactylus katharineri Malmberg, 1964 is summarized, concerning particularly its localization, host species spectrum and distribution in Eurasia. The morphogenesis and morphological-metrical variability of hard parts of opisthaptor are dealt with in detail. The pathogenicity of the parasite is stressed and methods for its control in fish-breeding farms are proposed.

Three new species of Gyrodactylus (Monogenoidea) from Varicorhinus capoeta gracilis (Keyserling) from the River Lenkoranka.

Three new species of Gyrodactylus Nordmann, 1832 are described from Varicorhinus capoeta gracilis (Keyserling) from the River Lenkoranka (Azebaijan SSR) as follows: G. varicorhini sp. n., G. capoetai sp.n. and G. mikailovi sp.n.

Two new species of Gyrodactylus (Monogenoidea) from Schizothorax intermedius McClelland from the River Kafirnigan.

Two new species of Gyrodactylus, namely G. kafirniganensis sp. n. and G. hemivicinus sp. n., are described from the fins and nostrils ofSchizothorax intermedius from the River Kafirnigan (Tajik SSR).

Variability of hard parts of opisthaptor of two species of Gyrodactylus nordmann, 1832 (Monogenoidea) from Phoxinus Phoxinus (L.).

The morphological and metrical variability of hard parts of opisthaptor was studied in the representatives of local populations of Gyrodactylus aphyae Malmberg, 1957 and G. macronychus Malmberg, 1957. The changes within the range of variability, which were observed during the year, correspond to regular and periodical changes in the environmental temperatures. The hard parts of opisthaptor were much smaller in specimens occurring during warm seasons than in specimens occurring during cold seasons. The temperature of about 8 degrees C forms a boundary between warm and cold seasons. The author assumes that similarly as G. aphyae and G. macronychus also other members of the genus Gyrodactylus living in climatic zones with regular change of seasons will react similarly on the annual variation in the environmental temperatures.

Gyrodactylus konovalovi sp. n. (Gyrodactylidae: Monogenoidea) from Phoxinus lagowskii Dybowski.

A new species of the genus Gyrodactylus, G. konovalovi, from the fins, gills and skin of Phoxinus lagowskii Dybowski is described. The specimens were found for the first time in the Mongolian People's Republic by Ergens and Dulmaa (1967) and were erroneously determined as D. macronychus Malmberg, 1957.

Redescription of two species of the genus Gyrodactylus Nordmann, 1832 (Monogenoidea) from Misgurnus anguillicaudatus.

A redescription is given of Gyrodactylus macracanthus Hukuda, 1940 and G. micracanthus Hukuda, 1940. G. paralatus Gussev, 1955 was placed in synonymy with the species G. macracanthus. Specimens determined by Ergens and Dulmaa (1968) to be G. paralatus are considered to be identical to G. micracanthus.