Size-age and histomorphological indicators of the Arctic grayling (Thymallus arcticus) of Putorana Nature Reserve
I.S. Nekrasov, A.G. Selyukov
Section: Population ecology
In waterbodies of high latitudes, ichthyofauna of the boreal foothill complex is highly sensitive to unfavorable factors. Poorly studied and extremely vulnerable freshwater ecosystems of the Subarctic require an especially close attention, considering conditions of global climate changes and increasing anthropogenic impact. An important method of their protection is creation of Specially Protected Natural Areas (SPNA) with purpose of preserving natural ecosystems in their intact state. However, territories that are not subjects of anthropogenic influence are extremely rare presently. While studying the Arctic grayling (Thymallus arcticus) of the Irkinda River (the Putorana Plateau), flowing through the territory of Putorana Reserve, some histopathologies pointing on an unstable ecological situation in this region were revealed. The noted initial stages of pathological process in branchial apparatus, namely - hyperplasia, aneurysms, fusion of respiratory lamellae, and an increase of cells layers in intercalary epithelium - indicate suppression of respiratory function. The reproductive system is less affected, but abnormalities are also found in it. Resorption of vitellogenic oocytes was revealed in 83% of individuals. Moreover, all the males of the Arctic grayling took part in the past spawning, while the number of spawned females was not more than 67%.
ISSN 1995-4301
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