sadko, Cottunculus Essipov [V. K.] 1937:90, Fig. 2 [Problemy Arktiki: sbornik statej, Arkticeskij i Antarkticeskij Naucno-Issledovatel'skij Institut, Glavnogo Uprevlemija Severnogo Morskogo Puti, Ministerstva Morskogo Flota SSSR. 1937 (no. 4); ref. 20998] Northern Kara Sea, between 78°07.2'-82°09'N, 65°50'-83°08'E, depth 300-690 meters. Syntypes: ZIN 30588-90 (1, 1, 1), 32170 (1, lost). •Valid as Cottunculus sadko Essipov 1937 -- (Neelov 1973:603 [ref. 7219], Nelson 1977:508 [ref. 7034], Nelson & Nakamura 1980:990 [ref. 26434], Fedorov & Nelson in Whitehead et al. 1986:1263 [ref. 13677], Nelson 1989:407 [ref. 12546], Yabe in Okamura et al. 1995:169 [ref. 22531], Mecklenburg et al. 2002:518 [ref. 25968], Parin et al. 2002:S92 [ref. 28300], Love et al. 2005:94 [ref. 37547], Byrkjedal & Orlov 2007:67 [ref. 29312], Mecklenburg et al. 2011:125 [ref. 31212], Dolgov 2013:918 [ref. 33112]). •Synonym of Cottunculus microps Collett 1875 -- (Byrkjedal et al. 2014:14 [ref. 33415], Mecklenburg et al. 2014:137 [ref. 33463], Mecklenburg et al. 2016:99 [ref. 34440]). Current status: Synonym of Cottunculus microps Collett 1875. Psychrolutidae: Psychrolutinae. Habitat: marine.