Reproductive Potential of the Lake Form of the Mongolian Grayling Thymallus Brevirostris (Kessler, 1879)

About the authors:

Innokentii S. Nekrasov, Instructor, Department of Zoology and Evolution Ecology of Animals, Tyumen State University; innok373@mail.ru

Alexander G. Selyukov, Dr. Sci. (Biol.), Professor, Department of Zoology and Evolution Ecology of Animals, University of Tyumen; ags-bios@yandex.ru

Abstract:

The article provides the dimensional and weight characteristic of a lake (benthophagic) form of the Mongolian grayling in a mountain cold water reservoir of Tuva. The reproductive potential of a grayling is studied. It is established that the females mature at the age of 4+, and the peak of spawning activity is observed in 5+. The males mature a year before females. In ovaries of the sexually mature fishes during the summer period, the senior generation of gametes is the cytoplasm vakuolization phase of oocytes; the next generations are represented by numerous previtellogenous oocytes; an insignificant part of females passes the next spawning season. In the testis a wave of spermatogenesis passes.

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