Effect of a Single Treatment of 17α-methyltestosterone for Masculinization in Kokanee Salmon (Oncorhynchus nerka)
2004 年 52 巻 3 号 p. 301-302
詳細
2004 年 52 巻 3 号 p. 301-302
In order to establish effective methods for masculinization in kokanee salmon (Oncorhynchus nerka), the effects of a single 2-hr immersion treatment of 17α-methyltestosterone (MT) on the sex of gonads during early development were investigated. All groups treated with 400μg/l MT at eyed eggs and juveniles stages (0, 10 and 16 days after hatching) showed higher percentages of male development (76.7-100%) ; this MT treatment resulted in 100% males in eyed eggs and juveniles 0 day after hatching. At all dosages of MT (50, 100, 200 and 400μg/l), eyed eggs showed higher percentages of male (76.2-97.0%) than the untreated controls (48-60%) ; the 200 and 400μg/l MT dosages produced a significantly higher percentage of males (96.1 and 97.0% each) than the other dosages. These results indicate that a single treatment of MT at a dose of 200-400μg/l is a highly effective method for masculinization in kokanee salmon at developmental stages from eyed eggs to just hatching.
