Here we report the first finding of a frenulate pogonophoran (Annelida, Siboglinidae) in the southern part of the Kara Sea. This finding was made in the Yenisei Gulf in the region of the highest methane concentrations, resulting from the degradation of permafrost under the influence of river flow. It has been suggested that pogonophorans are indicators of hydrocarbon manifestations of various genesis.
Keywords: Annelida; Frenulata; Kara Sea; Siboglinidae; Yenisei Gulf; biogeography; hydrocarbon manifestations; indicator organisms; pogonophorans.