Dunja Jakovcev-Todorovic

Macroinvertebrates along the Serbian section of the Danube River (stream km 1429–925)

Results of the investigation of the aquatic macroinvertebrate fauna along a 504 km stretch of the Danube River in Serbia are presented. A total of 74 macroinvertebrate taxa were observed during a 2001 survey. Oligochaeta and Mollusca were the principal components of the community with regard to species richness and abundance. Based on data on the qualitative composition of the macroinvertebrate fauna, a correspondence analysis divided the investigated stretch in three sectors — upper (Pannonian), Iron Gate sector and entrance sector to the Iron Gate stretch. The distribution patterns of certain species supported the division of sectors defined by correspondence analysis.

DISTRIBUTION OF NON-INDIGENOUS TUBIFICID WORM BRANCHIURA SOWERBYI (BEDDARD, 1892) IN SERBIA

ABSTRACT Recently, dispersion of invasive species became an important theme, since the man-aided outspread of the organisms was recognized as one of the major threats to the biodiversity. Aquatic biotopes are, due to its unique features, among the most disposed ecosystems to this kind of disturbance. Non-indigenous species of different origin were found among plants, vertebrates and invertebrates. Aquatic worm Branchiura sowerbyi (Beddard 1892) is obvious example of human induced dispersal of invertebrates. The aim of the study was to contribute to the cognition of the current distribution of this invasive species and to point up, once again, the risk of devastation of aquatic ecosystems caused by distribution of alien species. B. sowerbyi was for the first time observed in Serbia in 1972 in fish pond in Vojvodina. Since that time the worm spread its areal and now it could be found in a lot of ponds, channels, reservoirs and lowland rivers in Serbia. According to our results B. sowerbyi has been well adapted in artificial and modified water bodies in Serbia.