| Autor: |
T. H. Simpson, C. Whitehead, R. Johnstone, Alan F. Youngson |
| Rok vydání: |
1979 |
| Předmět: |
|
| Zdroj: |
Aquaculture. 18:13-19 |
| ISSN: |
0044-8486 |
| Popis: |
A sample of the all-male population of rainbow trout resulting from the dietary administration of 17α-methyltestosterone at a concentration of 3 mg/kg of food to juvenile fish during the 90-day period following “swim up” was grown to sexual maturity. It was observed that in many specimens there were deformations of the reproductive system which prevented the normal expression of milt although spermatozoa from the testes were viable. Sperm specimens removed surgically or normally expressed from mature fish were separately used to fertilise the mixed ova from untreated females. All the progeny of one such pairing were females. This indicates that in the rainbow trout it is the female sex which is homogametic. Samples of the all-female population which resulted from the dietary administration of 17β-oestradiol at a concentration of 20 mg/kg of food to rainbow trout fry during the 56-day period following “swim up” were also grown to maturity. The ova stripped from these fish were separately fertilised with mixed milt expressed from normal males. The progeny of two of five such pairings had a combined male to female ratio of 2.2, indicating that in rainbow trout the male is heterogametic for sex. The results were insufficient to permit any reliable estimate of the degree of impairment of the viability of the YY constitution. A method of producing single sex populations by the mating of sex reversed with normal fish is discussed. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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