köken: Borrowed from Czech Japonec or Russian япо́нец (japónec). By surface analysis, Japonia + -ec. For noun 2 sense 2, it was believed that this fish was a subspecies of the goldfish (Carassius auratus; Polish karaś chiński), which is native to Asia (including Japan).
Ci^([sic – meaning Te]) Japońce to jednak mają nasrane pod kopułą!