borealis, Petromyzon Girard [C. F.] 1858:377 [General report upon zoology of the several Pacific railroad routes, 1857; ref. 4911] Great Slave Lake, Northwest Territories, Canada. No types known. Based on Petromyzon fluvialis of Richardson 1836:294 (not of Linnaeus). •Synonym of Lethenteron japonicum (Martens 1868) -- (Vladykov 1973:5 [ref. 7159], Holčík 1986:199 [ref. 24819]). •Synonym of Lampetra japonica (Martens 1868) -- (authors). •Synonym of Ichthyomyzon unicuspis Hubbs & Trautman 1937 -- (Scott & Crossman 1998:61 [ref. 24570]). •Synonym of Lampetra camtschatica (Tilesius 1811) -- (Mecklenburg et al. 2002:62 [ref. 25968]). •Synonym of Lethenteron camtschaticum (Tilesius 1811) -- (Kottelat 1997:28 [ref. 22952], Sheiko & Fedorov 2000:14 [ref. 25650], Dyldin & Orlov 2016:543 [ref. 34656], Naseka & Renaud 2020:46 [ref. 37921]). Current status: Synonym of Lethenteron camtschaticum (Tilesius 1811). Petromyzontidae. Habitat: freshwater, brackish, marine.