Breed characteristics of the endobiotic fauna of the domestic reindeer

Purpose: to study the species diversity of the endobiontic fauna of the domestic reindeer of the Even and Chukchi breeds.Materials and research methods. There were studied the stomach contents of 69 adult reindeer of two breeds: the Chukchi breed from the Nizhnekolymsky region (40 heads) and the Even breed from the Oymyakonsky region (29 heads). The collection of the proventriculus contents was carried out during the mass slaughter of domestic reindeer in November 2022. The time interval after the slaughter of the deer before sampling was no more than 20-25 minutes. Samples were fixed with 10% formalin solution. The identification of species was carried out according to the determinants of Dogel V.A., 1929; Kornilova O.A., 2003, 2010. Species composition comparison of the endobiont infusoria of the animal fauna of the studied breeds was carried out according to the Jacquard-Malyshev similarity coefficient (Kj-m) and the Czekanowski-Sjørensen fauna commonality index (Ics).Results. As a result of the research, it was established that the species diversity of the endobiontic fauna of domestic reindeer of the Chukchi and Even breeds is insignificant, but differs. The species composition of endobiontic infusoria was determined on the basis of morphological and morphometric studies. In total, 18 species of infusoria belonging to 9 genera were identified, including 18 species of deer of the Even breed in 9 genera and 13 species of deer of the Chukchi breed in 6 genera. The basis of common species of infusoria for deer of the Chukchi and Even breeds bred in Yakutia is 3 species of Entodinium, 3 species of Epidinium, 2 species of Diplodinium and Ostracodinium, 1 species of Polyplastron, Enoploplastron and Dasytricha. The greater species diversity of endobionts of the Even breed can be explained by the fact that the Even breed belongs to the taiga type with a wider variety of food plants eaten than in the tundra deer of the Chukchi breed.