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Mitochondrial DNA (mtDNA) restriction analysis was used to examine the evolutionary and taxonomic relationships among 11 taxa of the subfamily Salmoninae. The genera Brachymystax and Hucho were closely related, diverging by sequence divergence estimates of 3·1%. Because the mtDNA sequence divergence between blunt-and sharp-snouted forms of Brachymystax (2·24%) was similar to divergence level of Brachymystax and Hucho, then taking into account the distinct morphological, ecological and allozyme differences between them, it is possible to recognize these forms as two separate species. The subgenus Parahucho formed a very distinct group differing by 6·35-7·08% (sequence divergence estimate) from both Brachymystax and Hucho and must be considered as a valid genus. The UPGMA and neighbour-joined phenograms showed that the five genera studied are divided into two main groupings: (1) Hucho, Brachymystax and Salvelinus; and (2) Oncorhynchus and Parahucho species. The mtDNA sequence divergence estimates between these groupings were about 8·1%. However, the subsequent bootstrap analysis of mtDNA RFLP data did not support the monophyly of the latter grouping. The concordance of morphological and mtDNA phylogenetic patterns is discussed. 1996 The Fisheries Society of the British Isles

Dogs are the hosts for a wide helminth spectrum including tapeworms, flatworms, and nematodes. These parasites affect the dog health and cause morbidity and mortality, especially in young and old animals. Some species, as Toxocara canis, Ancylostoma caninum, Dipylidium caninum, and Echinococcus spp. are well-known zoonotic parasites worldwide, resulting in high public health risks. Poor data about canine helminth species and prevalence are available in Russia, mainly due to the absence of official guidelines for the control of dog parasites. Moreover, the consequent low quality of veterinary monitoring and use of preventive measures, the high rate of environmental contamination by dog feces and the increase of stray dog populations, make the control of the environmental contamination by dog helminths very difficult in this country. This paper reviews the knowledge on canine helminth fauna and prevalence in Russia. Practical aspects related to diagnosis, treatment, and control of parasitic diseases of dogs in Russia are discussed.

SummaryNew cercariae similar to those of Paracoenogonimus (Cyathocotylidae, Prohemistomatinae), have been found in gastropods Amuropaludina and Cipangopaludina from reservoirs of the Primorsky Region (southern Far East of Russia). Two species of freshwater fishes (Pseudorasbora parva and Perccottus glenii) were experimentally-infected second intermediate hosts. Adults reared in chicken, Gallus gallus dom. They belong to a new species, Paracoenogonimus ussuriensis sp. n. They differ from those of P. szidati (Anderson, 1914) and Mesostephanus appendiculatus (Ciurea, 1916) (=P. skworzowi (Petrov, 1950) sensu Sudarikov 1961) by the size of the body, pharynx and ovary and, further, from the latter by the size of the suckers and testes. Adults differ from P. ovatus Katsurada, 1914 by the smaller dimensions of the oral sucker, pharynx and testes, and also by the absence of anterior interval between vitelline follicles.