Native to Russia, China, and potentially Japan and Korea (there is some confusion as to the latter, see Sato and Azuma 2002), P. amurensis was first collected as juveniles in the northern San Francisco Bay in 1986,its most likely mode of transport was attributed the release of veliger larvae with seawater ballast from NE Asia (Carlton et al., 1990). A very broad salinity tolerance and high survival rates in adverse environmental conditions (e.g. Kogut [2008] reported ~80% survival rate of specimens inside the guts of white sturgeon) are believed to have facilitated the transoceanic spread to San Francsico Estuary from its native range (Nicolini and Penry 2000). The latter study showed that twenty-four hour old embryos can survive a salinity range of 2-30 ppt.  McEnnulty et al. (2001) reported that larvae can withstand anoxic conditions. Within two years of its arrival in northern California, P. amurensis had in places reached densities in excess of 10,000 individuals/m², settled in a wide range of subtidal and intertidal sediments such as sand, clay and mud, occupied salinities between 0.1 and 33 ppt (Carlton et al., 1990), and was observed in temperature ranging from 5-25°C (Thompson and Parchaso, 2012).