An Etymological Dictionary of the German Language/Annotated/Karausche
Karausche, feminine, ‘crucian,’ Modern High German only; older variants, karaȥ, karûtsch; from French carassin, ‘crucian’?. Compare also English crucian, and its equivalent Italian coracino, Lithuanian karósas, Servian karaš, Czech karas, which forms are nearer to High German than to French; the final source is Greek κορακῖνος (Middle Latin coracînus).