33 National Marine Fisheries Service Fishery Bulletin First U.S. Commissioner established in 1881 of Fisheries and founder NOAA of Fishery Bulletin Abstract—A total of 69 specimens of The first data on the diet and reproduction of Fedorov’s lumpsucker (Eumicrotremus fedorovi) caught on the continental Fedorov’s lumpsucker (Eumicrotremus fedorovi) shelf and slope of Simushir Island in the northwest Pacific Ocean were dis- Ilya Gordeev (contact author)1,2 sected and studied for stomach con- 1 tents. The Fedorov’s lumpsucker was Kristina Zhukova found to feed mainly on the young of Svetlana Frenkel1 fish species, including the walleye pol- lock (Gadus chalcogrammus), northern Email address for contact author:
[email protected] lampfish (Stenobrachius leucopsarus), and northern smoothtongue (Leuro- 1 Russian Federal Research Institute of Fisheries and Oceanography glossus schmidti), crustaceans, such as 17 V. Kransnoselskaya Street Themisto pacifica, Primno macropa, Moscow 107140, Russia calanoids, gammarids, mysids, and caprellids, and squid. Histological analy- 2 Lomonosov Moscow State University ses of ovaries revealed iteroparity, deter- GSP-1 Leninskije Gory minate fecundity, group-sync hronous Moscow 119991, Russia ovarian development, and total spawn- ing. Testes were of an unrestricted lobu- lar type. Chorion and thick zona radiata of Fedorov’s lumpsucker correspond to the condition of eggs in specimens of other fish species that release demer- sal eggs. Absolute fecundity values The genus Eumicrotremus, 1 of 6 gen- et al., 2009; Berge and Nahrgang, of Fedorov’s lumpsucker in our study era of Cyclopteridae (Scorpaeniformes: 2013), lumpsucker species feed on var- were significantly less than those that Cottoidei), includes 18 valid species ious crustaceans, juveniles of squid have been reported for other species (Froese and Pauly, 2020).