학술논문
Determination of the Female-Biased Sex Ratio in Some Young-of-the-Year and Spawner Samples of the Threespine Stickleback Gasterosteus aculeatus by Environmental, Not Genetic, Factors.
Document Type
Article
Author
Source
Subject
*THREESPINE stickleback
*SEX ratio
*GENETIC markers
*ONTOGENY
*FEMALES
*SPAWNING
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Language
ISSN
1062-3590
Abstract
Genetic markers (sex-specific loci of Ga1 and Ga2) have been used to analyze the sex ratio of the threespine stickleback at different stages of ontogenesis. The progeny of all individually tested females includes both males and females, and no significant departures from a 1 : 1 sex ratio has been found in embryos from the natural nests. Juveniles did not demonstrate a sex bias up to one-and-a-half or two months of age, but in older juveniles, females prevailed (this fact has been reported for the first time). Females prevail among spawners, which mostly results from the predominant elimination of males during the spawning and post-spawning periods. The possible causes of this predominance are discussed. [ABSTRACT FROM AUTHOR]