Diversity of the genus Bunodera Railliet, 1896 (Trematoda: Allocreadiidae) in the northern part of Eastern Europe and North-eastern Asia, estimated from 28S rDNA sequences, with a description of Bunodera vytautasi sp. nov.

Phylogenetic relationship reconstruction and taxonomical analysis of trematodes of the genus Bunodera was carried out using 28S rDNA partial sequences along with a description and molecular characterisation of a new species, B. vytautasi sp. nov. A new species is reported from the intestine of Pungitius pungitius (Linnaeus, 1758), collected from Magadan Region, Russia. The diagnostic characters of B. vytautasi sp. nov. are the extension of vitelline fields from the oral sucker or posterior edge of the pharynx to the posterior extremity of the body, the confluence of vitelline fields within the forebody, the extension of the cirrus-sac to the posterior third of ventral sucker or further backwards with an outlet beyond the posterior edge of the sucker, and the presence of a unipartite internal seminal vesicle. Both Bayesian and Maximum Likelihood trees shared the same tree topology, in which the genus Bunodera was shown to be monophyletic. Representatives of the genus Bunodera were distributed into three well-supported clades: percid-infecting species (Eurasian species B. luciopercae and B. acerinae and North American B. luciopercae s.l.), gasterosteid-infecting species (amphi-Pacific B. mediovitellata and North American B. inconstans and B. eucaliae) and percid/gasterosteid-infecting species (Asiatic B. vytautasi sp. nov. and North American B. sacculata). Eurasian B. luciopercae and B. acerinae were more closely related to each other than to North American B. luciopercae s.l.

[BIODIVERSITY OF ACANTHOCEPHALANS (ACANTHOCEPHALA) IN FRESHWATER FISHES OF ASIATIC SUB-ARCTIC REGION].

The analysis of taxonomical and ecological diversity of acanthocephalans in fishes of Asiatic sub-Arctic region freshwaters, summarizing changes in modern views on species composition, life cycles, and ecology of background groups of these parasites is given. A priority role of studies provided by O. N. Bauer and his scientific school in organization and development of these aspects of acanthocephalology is demonstrated. Special attention is paid to the assessment of acanthocephalan biodiversity of the genus Neoechinorhynchus, the background group of freshwater fish parasites of the Asiatic sub-Arctic region, and an original key for their species is given. The distribution of acanthocephalans of the genus Acanthocephalus in northeastern Asia is analyzed and prospective study of this parasite group, evolutionary associated with freshwater isopods of the genus Asellus as intermediate hosts, is outlined. The absence of documented evidences on intermediate hosts of other background parasites of freshwater fishes in the region, acanthocephalans of the genus Metechinorhynchus, is revealed. It is assumed that subsequent taxonomic revisions based both on morphological and molecular genetic studies are necessary for the reliable revealing of species composition in each genus of the background acanthocephalans from freshwater fishes of Northern Asia. Theoretical significance of the study of acanthocephalan life cycles and revealing their natural intermediate hosts for the reliable estimation of structural and functional organization of their host-parasite systems in different parts of the range is substantiated and the possibility of the distribution of taxonomic conclusions in new territories is analyzed. A brief annotated taxonomical list of freshwater acanthocephalans of the Asiatic sub-Arctic region is given.