REPRODUCTION IN RAINBOW-TROUT - SEX-DIFFERENTIATION, DYNAMICS OF GAMETOGENESIS, BIOLOGY AND PRESERVATION OF GAMETES

Reproduction of rainbow trout, Oncorhynchus mykiss has received extensive research attention but many details remain unknown. The paper reviews the development of the testis and ovary, and outlines current methods of manipulating sex and gamete production. Sex differentiation occurs early in the life cycle, but the timing of active gametogenesis differs greatly between males and females. The dynamics of spermatogenesis is poorly understood as is the process of oocyte recruitment. Consequently, methods to improve fertility, manipulate gamete release, and cryopreserve sperm have been developed empirically. The management of sperm and ova, including the use of diluents, is reviewed along with a discussion of the lack of information on environmental, genetic, and husbandry factors that affect fertility and fecundity.