On the diversity and taxonomic status of graylings (Thymallus Thymallidae) from the Lena River

• Published in: Journal of ichthyology 2006-04, Vol.46 (3), p.234-246
• Main Authors: Knizhin, I. B., Kirillov, A. F., Weiss, S. J.
• Format: Article
• Language: English
• Subjects: Freshwater; Thymallus
• ISSN: 0032-9452; 1555-6425
• DOI: 10.1134/S0032945206030039

Two forms of graylings were distinguished in the Lena River, which differ in body coloration, the shape and pattern of the dorsal fin, and biological characteristics. With respect to these traits, the forms are divided between the upper and lower Lena. The first inhabits most of the basin, from the upper courses to the lower reaches, whereas the second inhabits the Lena delta and the adjacent arctic rivers and their tributaries. Comparative analysis of meristic traits revealed their low appropriateness for diagnosing Lena lineages as well as grayling populations inhabiting other northern rivers of Siberia. The body and fin coloration in the upper Lena form significantly differ from that found in forms and subspecies of graylings from the basins of the other rivers in the ranges of Eastern Siberian, Kamchatka, and Alaska. The lower Lena form should be classified with the Eastern Slberian subspecies T. arcticus pallasii and is closer to the populations of graylings from the rivers Anabar and Yana, and the rivers of the Chukot Peninsula and Alaska, and the upper courses of the Missouri These results are supported by analysis of the mitochondrial DNA of graylings throughout the Paleoarctic. Fur-ther studies of these lineages and phylogenetic relationships between Arctic lineages are necessary for the final deteramination of the taxonomic status of the upper Lena form.