The distribution of amphipods (Crustacea) in different habitats along the Mura and Drava river system in Croatia

In this paper the distribution of amphipods along two river system (Mura and Drava, northwestern Croatia) is described. Four amphipod species Gammarus fossarum Koch, 1835, G. roeseli Gervais, 1835, Niphargus valachicus Dobreanu & Manolache, 1933 and Synurella ambulans (F. Müller, 1846) were found in this region. In contrast to its oxbow lakes and surrounding fen region the amphipod biodiversity is low in the Mura and Drava River. G. fossarum is dominant and present only in the Mura River due to different environmental conditions in the various habitats and localities. G. roeseli is present in all types of researching habitats with the dominance in ditches. N. valachicus inhabits only eutrophic pools while S. ambulans is present in different kind of habitats viz. drainage ditch, tailrace canal and old river flow without its dominance in those habitats.