Dr. Éva Murai szerk.: Miscellanea Zoologica Hungarica 4. 1987 (Budapest, 1987)
Thuránszky, M.; Forró, L.: Data on the distribution of freshwater crayfish (Decapoda: Astacidae) in Hungary in the late 1950s
MISCELLANEA ZOOLOGICA HUNGARICA Tomus 4. 1987 p. 65-69 Data on the distribution of freshwater crayfish (Decapoda: Astacidae) in Hungary in the late 1950s By M. THURÁNSZKY and L. FORRÓ (Received October 16, 1986) ABSTRACT. Based on a survey made by the late Z. THURÁNSZKY and on the material of the Hungarian Natural History Museum, the distribution data of the three native crayfish species (A. astacus , A. leptodact y lus, A. torrentium ) are presented. KEY WORDS: Astacus astacus, A. leptodactylus, A. torrentium, Orconectes li- mosus distribution, Hungary The freshwater crayfishes were well-known members of the Hungarian fauna about a hundred years ago, when they could be found in nearly all standing and flowing waters. Crayfish always served as a delicacy in the Hungarian cuisine and its export was of great importance. There had been several famous "crayfish waters" and the specimens were easily sold in foreign markets. However, this situation has drastically changed, to catch crayfish today is a difficult task, consequently, its export has sharply declined. Besides economic importance, crayfish plays - with its animal and vegetable matter consumption - a significant role in the aquatic trophic system. It belongs to one of the most neglected animal groups in Hungary, since neither experiments nor tests have been carried out with it for a long time. The last comprehensive revision of the species composition, and the distribution of the Hungarian crayfish fauna were published by ENTZ (1909, 1914). Although his principal aim was to give a survey of the crayfish species native in Hungary, the distribution of the populations can also be conceived on the basis of his work. He mentioned such large water bodies as the River Danube, the Lake Balaton, etc. which were teeming with crayfish. According to ENTZ (1909, 1914) Hungary has three native Astacus species: A. astacus (Linnaeus, 1758), A. leptodactylus (Eschscholz, 1823), and A. torrentium (Schrank, 1803). The most wide-spread species is A. astacus. The species of A. leptodacty- lu s is frequent in the waters of the plains, however, only the former one is of economic importance. Following the above-mentioned papers only a few regional studies have been published in Hungarian. Besides the much debated, but not exactly known ravages of the crayfish plague, which were also mentioned by ENTZ (1909, 1914), the drastical changes in the natural environment (pollution, regulation, canalization, dredging) unfavourably influenced freshwater crayfish population of Hungary, too. With respect to the crayfish fungus (Aphanomyces astaci Schikora, 1903) and environmental conditions A. astacus is the most sensitive species, though the other two are not resistant to the crayfish plague either. Owing to the above-mentioned facts no reliable information is available on the distribution of these species and their native stocks. The occurrence of Orconectes limosus (Rafinesque, 1817) in the Danube at Budapest, further complicates the situation. It is very likely, that this species - which is resistant to the crayfish plague, and otherwise also is less sensitive to the environmental effects - worsens the prospects of survival of our native species. This paper publishes the results of the investigations concerning the freshwater crayfish populations carried out by Dr. Z. THURÁNSZKY between 1956 and 1960. The crayfish material of the Hungarian Natural History Museum collected in 1910-1960 is also included to
