The occurrence of M74 syndrome in female Atlantic salmon, Salmo salar L., belonging to two populations returning to spawn in Polish rivers in the fall of 2004 and three from pond cultivation were investigated. Eggs from total of 218 female specimens were investigated from rivers in northern Poland (80 – Darłowo, 72 – Miastko, 66 – Świbno). The study method applied involved comparing the concentrations in eggs of red (astaxanthin, canthaxanthin) and yellow (lutein, zeaxanthin) carotenoids. The specific carotenoids were determined with column chromatography (CC), thin layer chromatography (TLC) and high performance liquid chromatography (HPLC). The eggs of the investigated female Atlantic salmon were divided into three groups according in color: yellow, yellow-orange, and orange. Fifteen carotenoids were identified in the investigated Atlantic salmon females. Red carotenoids dominated in orange and yellow-orange eggs, while yellow ones dominated in yellow eggs. M74 syndrome was identified in 36 females, which represented 16.5% of all the investigated Atlantic salmon females.

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