Reproductive efficiency of turbot (Scophthalmus maximus L.) females treated with LHRHa

Abstract

A broodstock of 25 females with different maturity stages were induced to spawn with a single, dosis of 3. pg/Kg .of LHRHa. A response was experienced by 100% of the most advanced females (stages II arid III). The less advanced females (stages 0 and 1) were induced again two weeks later; using the same dosis divided in, two consecutive days, and a response in 50% of females was obtained. The data obtained were compared with those of females from the same broodstock but naturally matured, not injected. Induced females showed a clear decrease both in the number of ovulations and in the intervals between ovulations, and an increase in the number of ovocytes per ovulation. Besides, three of the naturally matured females were induced with the same dosis used initially. Two of them were induced at the end of the spawning, period and no respense was detected; nevertheless another,female,induced during the spawning period had a very good synchronization of the intervals between ovulations from the day of injection until the end of the spawning period.