The Japanese sturgeon, or Amur sturgeon (''Acipenser schrenckii'') is a
species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
of
fish
Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of ...
in the family
Acipenseridae found in the
Amur River basin in
China and
Russia
Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-eig ...
. Claims of its presence in the
Sea of Japan
The Sea of Japan is the marginal sea between the Japanese archipelago, Sakhalin, the Korean Peninsula, and the mainland of the Russian Far East. The Japanese archipelago separates the sea from the Pacific Ocean. Like the Mediterranean Sea, i ...
need confirmation.
The species has 11–16 dorsal, 34–47 lateral, and 7–16 ventral scutes. Their dorsal fins have 38–53 rays and 20–35 anal fin rays. They also have greyish-brown backs and pale ventral sides. The species could reach up to 3 m (9.8 ft) in length, and weight over 190 kg.
[Description and distribution](_blank)
The species is considered to be
critically endangered.
Habitat and ecology
The Japanese sturgeon is
benthic. Their main food sources are aquatic insect larvae, bone fish and mollusks. One study suggests that the type of aquatic insect larvae eaten by juvenile Japanese sturgeon depends on the season, where
mayfly nymphs are eaten more frequently in Spring and Fall, and
midge larvae are eaten more frequently in Summer.
The females mature at 9–10 years of age, and males at 7–8 years. They start to
migrate in the autumn. They live for 65 years.
References
Further reading
* Masuda, H., K. Amaoka, C. Araga, T. Uyeno and T. Yoshino (1984). The fishes of the Japanese Archipelago. Vol. 1 (text). Tokai University Press, Tokyo, Japan. 437 p. (text), 370 pls.
*Journal Coll. Sci. Imp.Univ.,Tokyo, "23", (7).
*Global Biodiversity Information Facility http://data.gbif.org/species/13576254/. Viewed 27 January 2010.
Acipenser
Fish of East Asia
Freshwater fish of China
Fish of Russia
Amur basin
Fish of Japan
Sea of Japan
Critically endangered fish
Critically endangered biota of Asia
Fish described in 1869
{{Acipenseriformes-stub