L. Forró szerk.: Miscellanea Zoologica Hungarica 10. 1995 (Budapest, 1995)

Nesemann, H., Pöckl, M.; Wittmann, K. J.: Distribution of epigean Malacostraca in the middle and upper Danube (Hungary, Austria, Germany)

D. haemobaphes is a Ponto-Caspian gammarid species of wide distribution. The taxonomic situation of its freshwater form, named fluviatilis Martinov, 1919, is not clear. It is especially questionable, whether the use of the third name is justified (Jazdzewski 1980). Therefore, we retained the name D. haemobaphes also for the riverine form. The species advances very high upstream the larger Ponto-Caspian rivers and not so far in the smaller ones. It was also observed in the offshore lakes of the Black and Marmara seas (Brtek & Rothschein 1964, Kaneva-Abadzieva 1972). The invasion of Lake Balaton by D. haemobaphes from the Danube via the River Sió can be dated rather precisely to the middle of the 1950s (Ponyi 1956, 1958). According to this author, Dikero gammarus spp. appeared simultaneously with the introduction of Limnomysis benedeni into the lake (Woynarovich 1955). In the Pannonian lowland, D. haemobaphes also entered the lower reaches of some large Danube tributaries, such as the Száva, Dráva, Sió, Rába, Tisza, Kőrös and Sebes-Kőrös (Dudich 1927, Botos et al. 1990). In Austria, it was collected in the Danube at Hainburg and Nussdorf near Vienna (Vornatscher 1965). It was, however, not collected by Kothé (1968) in the Bavarian section of the river. In the last two decades it massively expanded its distribution in the upper Danube. Nowadays it is very abundant at least as far upstream as Kehlheim. Since 1992, D. haemobaphes invaded the Rhine river basin via the recently constructed Main-Danube-Canal. It is now frequently recorded from the Bavarian section of the Main River (Schleuter et al. 1994) Dikerogammarus villosus (Sovinski, 1894) Material: Danube at Mohács, 18. 09. 1930, leg. Dudich, E.; Danube at Dunakömlöd, 11. 09. 1947; Danube at Harta, 05. 09. 1991; Danube at Dunaföldvár, 11. 09. 1947, leg. Loksa, I., 05. 09. 1991; Danube at Dunaújváros, 05. 09. 1991, leg. Ofenböck, T. & H. Nesemann; Danube at Római-fürdő near Fig. la-b. Dikerogramniarus. villosus, different colour variants from dorsal and lateral view, from Danube at Dunaremete