ECOLOGY-BIOCHEMICAL ASPECTS OF THE REPRODUCTIVE SYNDROME M74 IN SALMONIDS

Here we review the literature and global experience about M74 syndrome. Potential ecological factors and biochemical mechanisms of reproductive disorders in salmonids were discussed. We present the world experience and some results of our own research in Bulgarian trout farms on the technological aspects of the M74 syndrome. The antioxidants and thiamine deficiency signs and requirements of salmon, brown and rainbow trout were considered. For the first time our research team opines that with M74 syndrome are affected also male gametes and worsened parameters of the spermograme. The use of Bulgarian semen protective media 49282, 49283 и 49397 for trout sperm fertility improving was proposed. Highlights of biological methods for preventing and dealing with reproductive disorders in salmonids are presented. The data are illustrated with original photographs. Indicated, that energy metabolism of trout embryos may use as a biochemical indicator characterizing the status of hydroecosystems. Additional biochemical and ecological studies in Bulgaria for determination of the M74 syndrome are proposed.