One single female specimen of Chinese Mitten Crab, Eriocheir sinensis (Milne-Edwards, 1853), was found in the Bulgarian stretch of the Danube River on 16 September 2005. It was caught by fishermen with fishing nets near Radetski Island (436 r. km) upstream the town of Tutrakan.
The native range of the species is Southeast Asia from southern China to the Korean Peninsula. In Europe it was first recorded in the German river Aller in 1912, most likely introduced with ballast water releases. Since then it was introduced in most North and Baltic Sea countries in Europe becoming very common in Germany and common in the Netherlands (NOBANIS). In the Danube River, it was reported from Romania (Skolka 1998), Austria (Rabitsch, Schiemer 2003), Serbia (Paunovic et al. 2004) and Hungary (Puky et al. 2005).
The Chinese Mitten Crab is easy to identify by the extensive mitten-like covering on the claws. It is a catadromous species which migrates long distances upstream from the coasts and spends most of its life in freshwaters. It is opportunistic omnivore species, tolerant to wide range of environmental parameters. The mass occurrence of the species and its burrowing and predator activities can cause bank erosion, damage to the hydro-technical facilities, damage to commercial and recreational fishing, as well as reduction and altering the structure of fresh and brackish benthic invertebrate communities.

References
Paunovic M., Cakic P., Hegedis A., Kolarevic J., Lenhardt M. 2004. A report of Eriocheir sinensis (H. Milne Edwards, 1854) [Custacea: Brachyura: Grapsidae] from the Serbian part of the Danube River. Hydrobiologia 529: 275-277.
Puky M., Reynolds J. D., Schád P. 2005. Native and alien Decapoda species in Hungary: distribution, status, conservation importance. Bull. Fr. Pêche Piscic. 376-377: 553-568.
Rabitsch W., Schiemer F. 2003. Chinesische Wollhandkrabbe (Eriocheir sinensis) in der österreichischen Donau festgestellt. Österreichs Fischerei 56: 61-65.
Skolka M. 1998. Increase of biodiversity by immigration – new species in the Romanian fauna – Beroe ovata, Corbicula fluminea, Doridella obscura, Eriocheir sinensis, Callinectes sapidus. Universitatea Bacău, Studii şi Cercetări de Biologie, 4: 235-240.

Contact persons:
Yordan Kutsarov, Kalimok-Brashlen Protected Area, Tutrakan, Bulgaria, This e-mail address is being protected from spambots. You need JavaScript enabled to view it
Teodora Trichkova, IBER-BAS, This e-mail address is being protected from spambots. You need JavaScript enabled to view it

Photos: Y. Kutsarov