Japanese sturgeon

The Japanese sturgeon or Amur sturgeon (Acipenser schrenckii) is a species of fish in the family Acipenseridae found in the Amur River basin in China and Russia. Claims of its presence in the Sea of Japan 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 can reach up to 3 m in length, and weigh over 190 kg. The species is considered to be critically endangered.

Habitat and ecology
The Japanese sturgeon is benthic. Their main food sources are aquatic insect larvae, bony 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.