In several Russian northern lakes and rivers, Arctic cisco Coregonus autumnalis, least cisco C. sardinella, peled C. peled, tugun C. tugun, broad whitefish C. nasus, whitefish C. lavaretus and vendace C. albula were sampled in periods of officially permitted commercial fishery. Special attention was paid to contents (mg g-1 of wet weight) of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in muscle tissues (filets), which are essential for human nutrition. The highest values of EPA + DHA content in semi-anadromous fish and freshwater fish were recorded for C. autumnalis from the Yenisei River, 17.60 mg g-1 wet weight, and for C. lavaretus from the Sobachye Lake, 16.61 mg g-1 wet weight, respectively. Intra-genus variations of EPA + DHA contents of Coregonus species were from 1.87 to 17.60 mg g-1 wet weight. Since the congeneric species were genetically close to each other, the variations in EPA and DHA contents were thought to be caused primarily by ecological factors: migrational capability, type of feeding and trophic status of aquatic ecosystems. In general, the majority of studied species appeared to be of a high nutritive value for humans, although unfavorable environmental conditions could considerably diminish this value.
Keywords: Anadromous fish; Benthivory; Docosahexaenoic acid; Eicosapentaenoic acid; Freshwater fish; Planktivory.