Beluga

Beluga, Acipenser huso, the largest cartilaginous sturgeon fish (Ganoidei, Chondrostei), weighing up to 500 kg or more. It lives in the Caspian and Black Seas and in the rivers flowing into them. The meat is used for food, although it is rather coarse. The roe is of high quality. The dorsal string (chorda dorsalis) is dried and, under the name of vyaziga, is used as food. The inner layer of the swim bladder is removed, dried, and sold as "fish glue." Beluga, like other sturgeon fish such as stellate sturgeon (A. stellatus), sterlet (A. ruthenus), etc., is harmless, but under the influence of certain causes, some specimens of it and other sturgeons acquire poisonous properties and become the cause of human poisoning by fish toxin. Such a poisonous fish does not arouse any suspicion either in appearance or in taste. Three forms of fish poisoning are distinguished: 1) Ichthyismus neuroticus, 2) Ichthyismus choleriformis and 3) Ichthyismus exanthematicus. It is possible that these forms of poisoning are caused by fish toxin of different nature.