Stellate sturgeon | European Tracking Network

Stellate sturgeon

Acipenser stellatus

Species description and statusComparatively big fish with elongated body and very long, slender rostrum, which is typically about 50 – 60% of head length. Possesses two pairs of barbells originate closer to mouth than tip of rostrum. Barbells much smaller compared to other sturgeon species. Middle of the upper lip indented; lower lip interrupted. Five rows of scutes along the body. Each of the scutes terminates in a prominent, sharp, hook-like appendage. Between rows of scutes, body covered with numerous tiny denticles. Scutes remain prominent on adults and are never absorbed even in old individuals. Maximum size is up to 2 m and about 80 kg (Kozhin, 1964). Body coloration black with pale scutes and denticles. A diadromous species native to the Caspian, Black and Azov Seas. Accidently it has been recorded from waters as far west as the Sea of Marmora and Aegean Sea of the Mediterranean (Hochleichner 1999). In the Caspian Sea, the population is comprised of three distinct subpopulations known as intraspecific forms; Volga, Ural, and Kura (Vescei et al., 2007). Populations occurred also in the Danube, Dnieper, Kuban, Don, Terek, Sulak, Samur, and Kura rivers (Berg 1948, Hensel & Holcik 1997). Now believed to be extinct from the upper and middle Danube after the construction of Iron Gate II Dam and spawning migrations in the Lower Danube greatly reduced (Bacalbasa-Dobrovici 1997).

Presently, the most abundant of the diadromous Ponto-Caspian acipenserids, however most population suffered major declines in the last decades of the 20th Century. Biggest threats are uncontrolled poaching, hydropower dams construction and habitat degradation. The species is included in Appendix II of CITES and it is categorized as Critically Endangered by IUCN with decreasing population trend.

Figure 1. Distribution of Stellate Sturgeon (Acipenser stellatus) taken from fishbase.org

Knowledge gaps: Migration routes, periods of migration and the distribution in marine and transitional waters are not well known. The effect of hydropower dam construction on the movements and reproduction success is also poorly understood. Tagging studies show that there are still reproducing populations in Lower Danube, but data are still not sufficient to give information about the exact places and time of spawning. Spawning grounds are still very poorly investigated. Few sites are known in Romanian stretch of the river, but still no data about spawning sites in the Bulgarian part. More information on the Black Sea movements and distribution, as well as on the wintering grounds is required. 

Regions of interest: The regions of biggest interest are Lower Danube and Black Sea.

Telemetry tools: Acoustic telemetry with data loggers are the most used tools for characterizing the movement patterns in Danube River. Telemetry methods should be also used to research Stellate Sturgeon movements and behavior in the transitional, coastal and marine waters of the Black Sea. Tagging of juvenile specimens by PIT-tags is also a possibility for surveying their biology and migration.

Benefits within the ETN: Using the ETN to further characterize Stellate Sturgeon migration and behavior in Lower Danube and Black Sea would greatly enhance our ability to better understand and manage this critically endangered species. This is a common territory of few countries so joint research efforts, sharing of infrastructure and international collaborations are required. In addition, ETN would give additional insights in the location of the spawning grounds and environmental preferences of the species.

Contacts: Tihomir Stefanov (tishos@gmail.com)

References:

  • Bacalbasa-Dobrovici, N. 1997. Endangered migratory sturgeons of the lower Danube River and its delta. Environ. Biol. Fish. 48: 201–207.
  • Borzenko, M.P. 1964. The present state and forecasting of fluctuations in the stocks of Acipenser stellatus in the Caspian Sea with regulated river flow. pp. 259 – 286. In: Sturgeons of the Southern Seas of the USSR. VNIRO Proceedings 52, VNIRO Publishers, Moscow (in Russian).
  • Berg, L.S. 1948. The Freshwater Fishes of the USSR and Adjacent Countries. English translation. Israel Program for Scientific Translations, Jerusalem, 1965. 505 pp.
  • Hensel, K. & J. Holcik. 1997. Past and current status of sturgeons in the upper and middle Danube River. Environ. Biol. Fish. 48: 185–200.
  • Hochleichner, M. 1999. The Sturgeons and Paddlefishes (Acipenseriformes) of the world. Aquatech Publications, Vienna. 163 pp.
  • Kozhin, N.I. 1964. Sturgeons of the USSR and their reproduction. pp. 32 – 59. In: Sturgeons of the Southern Seas of the USSR. VNIRO Proceedings 52, VNIRO Publishers, Moscow (in Russian).
  • Legeza, M.I. 1973. The present distribution of sturgeons (the Family Acipenseridae) in the Caspian Sea. J. Voprosy Ichthyologii (Problems of Ichthyology) Vol. 13, 6(63): 1008 – 1015.
  • Levin, A.V., O.P. Bezrukavnikov & M.I. Pirogovskii. 1981. Vertical distribution of Acipenserids in Northern part of the Caspian Sea. pp. 143 – 144. In: Efficient Methods of Sturgeon Menagement. Book of abstracts, Volgograd (in Russian).
  • Vlasenko, A.D. & P.V. Veshchev. 2001. Assessment of the status of Caspian stellate sturgeon stocks and predication of its catch in 2002. pp. 155 – 163. In: Fisheries Research in the Caspian Sea, Astrakhan.Pirogovskii, M.I., L.I.
  • Sokolov & V.P. Vasil’ev. 1989. Huso huso (Linnaeus, 1758). pp. 295–344. In: J. Holˇc´ık (ed.) The Freshwater Fishes of Europe, Vol. I/II: General Introduction of Fishes, Acipenseriformes, AULA-Verlag, Wiesbaden.
  • Vescei, P., D. Peterson, R. Suciu, E. Artyukhin. 2007. Threatened fishes of the world, Acipenser stellatus, Pallas, 1771 (Acipenseridae). Environmental Biology of Fishes, 78: 211–212.