The
kaluga (
Huso dauricus) is a large predatory
sturgeon found in the
Amur River basin. Also known as the
river beluga, they are claimed to be the largest freshwater fish in the world, with a maximum size of at least 1,000 kg (2,205 lb) and 5.6 m (18.6 ft). Local fishermen have suggested that the kaluga can grow well up to 20 ft in length and can weigh around 1,500 kg. The kaluga is one of the biggest of the sturgeon family. Like the slightly larger
beluga, it spends part of its life in salt water. Unlike the beluga, this fish has 5 major rows of dermal scutes, nail-like teeth in its jaws, and feeds on
salmon and other fish in the Amur. They have gray-green to black backs with a yellowish green-white underbelly.