Zarigani (Cambaroides japonicus) is a species of crayfish which lives only in Japan.
It is small in size (6 cm) and grayish in color. Its front claws are much weaker than those of other crayfish. The Zarigani needs low temperature and high water purity, so it lives in upper streams of rivers or lakes in highlands. Its distribution is Hokkaido and northern Tohoku (the northern area of Honshu).
The Environmental Agency (now Ministry of Environment) of Japan added it as a Vulnerable Species (IUCN category) to the Red Data List in 2000. It is thought that the causes of its decrease are corruption of water quality and the spread of the American crayfish Pacifastacus leniusculus, which was imported in the 20th century and has steadily proliferated in northern Japan. Some suspect that this American crayfish has carried some plague, such as the crayfish plague known in Europe, that eliminates Zarigani.
Zarigani (Cambaroides japonicus) is a specie of crayfish which lives in only Japan.
Zarigani needs low temperature and high degree of water purity, so lives in upper steam of river or lake of highland.
It is thought that the causes of decreasement are corruption of water quality and the extention of American crayfish Pacifastacus leniusculus, which was imported in the 20th century and have constantly proliferated in northern Japan.