Rumen bacterial community of young and adult of reindeer (Rangifer tarandus) from Yamalo-Nenets Autonomous District of Russia

The aim of the work was to compare the taxonomic composition of the rumen procariotic community in young and adult individuals of Nenets breed reindeer (Rangifer tarandus ) from the central part of the Yamal region by using the NGS method (next generation sequencing) and compare the microbiome composition of reindeer with the microbiome of their initial vegetation food material. The obtained data showed that the dominant position in microbial communities, like that of other ruminants, was occupied by representatives of phylum Firmicutes and Bacteroidetes, whose total share between observed groups did not differ significantly. The composition of the microbiome of the rumen of the investigated group of animals was completely different from the microbiome structure of the initial vegetation cover. Digestion of vegetation by reindeers resulted in complex transformation in the initial plant microbiome and an increase of biological diversity which was expressed in operational taxonomic unit (OTU) numbers increasing and changes in indexes of alpha-diversity parameters. According to the results of alpha- and beta- diversity of the rumen microbial communities, the greatest uniqueness was revealed for the microbiomes of the adults in comparison with calves and young. The presence of changes in the biodiversity indexes of the rumen microbiota in the reindeer, examined by us, confirm the opinion of the researchers that the microbial community may also reflect the physiological state of the animals. It has also been demonstrated that the presence of the phylum Verrucomicrobia, and the genera Stenotrophomonas, Pseudomonas, etc., may be specific to Nenets breed reindeer and have a pattern with their presence on various plants and lichens that are part of the reindeer diet. This is partially confirmed by data on plants microbiome taxonomy

Diversity and Distribution of Helminths in Wild Ruminants of the Russian Arctic: Reindeer (<i>Rangifer tarandus</i>), Muskoxen (<i>Ovibos moschatus</i>), and Snow Sheep (<i>Ovis nivicola</i>)

The Russian Arctic supports wild sympatric ruminants and their data-deficient helminths. In this study, we: (1) collected fecal samples of wild and semiwild reindeer (Rangifer tarandus), muskoxen (Ovibos moschatus), and snow sheep (Ovis nivicola) across Palearctic North territories: Arkhangelsk Oblast (including Novaya Zemlya archipelago), Karelia and Sakha Republics, Kola, Yamal, Taimyr, and Chukotka Peninsulas, Bering, Svalbard, and Wrangel Islands; (2) conducted a coprological survey (noninvasive life-time method preferable for protected animals) to obtain eggs and larvae of helminths inhabiting digestive, respiratory, nervous, and muscular systems; (3) identified helminths according to their morphology and DNA sequences; (4) estimated parasite load per host; (5) analyzed our findings. Varestrongylus eleguneniensis (in reindeer) was reported for the Palearctic for the first time, while Orthostrongylus sp. was reported both for R. tarandus and for the Palearctic for the first time. Capillarid-type eggs were reported for snow sheep for the first time. The question of the role of wild Arctic ruminants as vectors for rotifers was raised