PRODUCTION OF MASCULINIZED RAINBOW TROUT (ONCORHYNCHUS MYKISS) FEMALES USING 11-beta-HYDROXYANDROSTENEDIONE

摘要

There has been growing demand in recent years for the culture of monosex female fish populations for the consumer market. This is achieved in salmonid fishes by fertilizing eggs with milt obtained from masculinized females. Although it is also possible to obtain a female population through hormonal therapy (Johnstone et al., 1979), the application of hormones in the production of food is generally forbidden in most countries. Traditionally, sex reversal from female to male in rainbow trout has been achieved by treating the fish with small doses of methyltestosterone in the starter feed from days 60 to 90 following the beginning of exogenous feeding. However, the most recent studies indicate that the application of 11-B-hydroxyandrostenedione is moreeffective and safer in terms of overdose risks (Demska-Zakejs et al. 1999). This was proved in our research which resulted in mass masculinization of gynogenetic (only female) rainbow trout.