Kaluga (fish)

The kaluga (Sinosturio dauricus), also known as the kaluga sturgeon, river beluga sturgeon, is a large predatory sturgeon found in the Amur River basin from Russia to China and near Hokkaido in Japan. With a maximum size of at least 1,000 kg (2,205 lb) and 5.6 m (18 ft), the kaluga is one of the biggest of the sturgeon family. Unlike the slightly larger beluga, this fish has five major rows of dermal scutes and feeds on salmon and other fish in the Amur with nail-like teeth in its jaws. They have grey-green to black backs with a yellowish green-white underbelly. Akin to the beluga, it spends part of its life in salt water, being semi-anadromous. The kaluga has been hunted to near extinction for its valuable roe. Despite constant anti-poaching patrols, poachers still continue to catch the fish. In Russia, illegally fishing for kaluga anywhere on the Amur River is a felony punishable by law. However, kalugas are known to have an aggressive nature, and instances of them toppling fishing boats and drowning fishermen have been reported, although no concrete evidence exists of them assaulting or hunting people.