Beluga - Huso huso

Beluga is the biggest freshwater fish species, reaching the length of 6 m, while the weight is exceeding 1000 kg. Body is massive and narrowing toward tail. Number of dorsal scutes is 9 to 17, lateral 37 to 53, ventral 7 to 14. The branchiostegal membranes are joined to one another and separate from isthmus. Mouth is big, semicirculary shaped and apparently its biggest width exceeds half of head width in that spot.

Beluga is widely distributed throughout the Caspian, Azov, Adriatic and Black sea , and also in big rivers which confluence into these seas. Beluga used to go, throughout the Danube River, as far as Vienna. With building of the “Djerdap II” dam, beluga's migration path was shortened on 863 km of Danube River flow. During the period in which beluga inhabits sea water, it occupies pelagic zone, and the depth is depending on availability of food resources. During migrations, beluga is moving through bottom zone of the river, although it often goes to surface.

(www.fishbase.org)

Maximal recorded age was 118 years. Males become sexually mature at the age of 12-16 years and females at 16-22 years. Spawning intervals are 4-7 years for males and 5-7 years for females. Spawning occurs on rocky and gravelly bottoms, at the deep water. It is believed, that there are two races, spring and winter, with different migration periods, which leads to two separated peaks in migration. One number of individuals migrates in summer and autumn, spending winter in rivers and spawns in spring of next year, while others are migrating at the end of winter and early spring, and spawning is in same year. Individuals which spawn in autumn are spawning more upstream, then those which migrate in spring.

Fall of beluga catch

Beluga diet is varied, both during the time of year and development. While juveniles are mostly fed on benthic invertebrates, adults are piscivorous predators in pelagic zones of sea, feeding mainly on larger fish species from genus Alosa, Aspius and Engraulis. During the period of migrations, adults consume also crabs and mollusks.

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

Temporary ban on beluga catch is determined for period from 1 st of March until 30 th of September, while minimal length for catch is 250 cm (“Official Gazette of Republic Serbia“, No 100/2003). On the other hand, by Decree of placing under control use and trade of wild flora and fauna (“Official Gazette of Republic Serbia“, No 31/2005) ban on beluga catch is shorter, from 1 st of April until 31 st of May, while catch limit for length is 180 cm for males and 210 cm for females. Beluga's catch statistics were conducted relatively well during the 1960-1996, after which, due to political and economical situation in the country, it become incomplete and unreliable. From 2003, due to ratification of CITES, beluga's catch statistic are conducted again. According to data from 2004, overall catch was 13 individuals, with total weight 1584 kg, including 3 males (83-93 kg) and 10 females (61-210 kg). All individuals were caught in period from 08.10 – 16.11.2004., except one female, which was caught in April for requirements of artificial spawning (200 kg). During 2004, 5 crews of fishermen participated in beluga catch, every crew with two members. Catch was conducted on Danube River, downstream from “Djerdap II” dam, on 3 km long area. Research conducted during 2001 showed that in catch were also present 47 (female) and 35 (male) years old individuals.

Taken from: 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.

Internet presentation was funded by Minstry of Environmental Protection of Republic Serbia. Webdesign & maintenance: Ivan Jarić ijaric@ibiss.bg.ac.yu