Beluga - Huso huso

Beluga is the biggest freshwater fish species, reaching the length of 6 m, while the weight can exceed 1000 kg. Body is massive and narrowed towards the tail. Number of dorsal scutes is 9-17, lateral 37- 53, ventral 7-14. Branchiostegal membranes are mutually joined and separated from the isthmus. The mouth is big, semicirculary shaped and its biggest width visibly exceeds in that spot half of the head width.

Beluga is widely distributed throughout the Caspian, Azov, Adriatic and Black sea, and also in large rivers that belong to those basins. In the Danube River, beluga used to migrate as far as to Vienna. With the construction of the “Djerdap II” dam, beluga's migration path was shortened to 863 km of the Danube River flow. During the period when beluga resides in the sea, it occupies pelagic zone, and the depth depends on the availability of food resources. During the migration, beluga is moving through the bottom zone of the river, although it often visits the surface.

(www.fishbase.org)

Maximum recorded age is 118 years. Males become sexually mature at 12-16 years and females at 16-22 years of age. Spawning intervals are 4-7 years for males and 5-7 years for females. Spawning occurs on rocky and gravelly bottoms in the deep water. It is hypothesized that there are two races, spring and winter race, with different migration periods that produce two distinct migration peaks. One part of individuals migrates in summer and autumn, spends the winter in rivers and spawns next year in spring, while other individuals migrate at the end of the winter and early spring, and spawn in the same year. Individuals that migrate during the autumn are spawning more upstream from those that migrate during the spring.

Beluga catch decrease

Beluga diet can vary depending on the time of the year and the developmental stage. While the juveniles mostly feed on benthic invertebrates, adults are piscivorous predators in pelagic zones of the sea, feeding mainly on larger fish species from genus Alosa, Aspius and Engraulis. During the period of migrations, adults also consume crabs and mollusks.

Beluga range; green area - present, red area - extinct (www.cites.org)

Starting from 2009, there is a permanent ban established for beluga catch (“Official Gazette of Republic Serbia“, No 36/09).

Beluga catch statistics were kept relatively well during 1960-1996, after which, due to political and economical situation in the country, they became incomplete and unreliable. Since 2003, due to the ratification of CITES, beluga catch statistics became more reliable and complete. According to the data from 2004 to present time, overall beluga catch was only 13 individuals, with 1584 kg total weight, including 3 males (83-93 kg) and 10 females (61-210 kg). All individuals were caught during theperiod 08.10 – 16.11.2004, except one female, which was caught in April for the needs of artificial spawning (200 kg). During 2004, five crews of fishermen participated in beluga catch, every crew with two members. Catch was conducted on the Danube River, downstream from “Djerdap II” dam, on the 3 km long river stretch. Research conducted in 2001 showed that there were older individuals present in the catch, such as 47 year old female and 35 year old male.

Source: Lenhardt, M., Hegediš, A. and Jaric, I. (2005). Action plan for sturgeon species management in fishery waters of Republic Serbia. Institute for Biological Research “Siniša Stankovic”, p. 21. Developed for Ministry of Science and Environmental Protection of Republic Serbia.

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