The Distribution of Astacidae (Decapoda) Fauna in Kosovo and Metohija, Serbia - Page 03

The conducted study did not have a quantitative approach, so the number of individuals found was not relevant. The history of collection of crayfish species in this area is long-lasting. In the period between 1982-1996, the author and his associates caught dozens of individuals A.astacus for lab exercises with students, in the river Nerodimka at the site of Donja Grlica village. Some specimens have weighed up to 300 g, and have been up to 30 cm in length. By inflow of waste water from Uroševac Town in the Nerodimka River, the A.astacus population withdrew to the upstream parts of the river. The expansion of A. torrentium in hydrogeographic networks of Europe was suppressed by the phylogenetically younger population of species A.astacus, inhabiting waters of Eastern Europe and the Balkan Peninsula. Suppressed from the lowlands the A. torrentium species retreated into mountain streams and rivers. The adaptive plasticity of A. torrentium enabled it to adapt to high mountain river ecosystems. This species was found in the source branches of all three hydrographic basins: the Adriatic, Aegean and the Black Sea. This zonation in the species distribution of the populations of A.astacus and A. torrentium registered in streams in the region of Kosovo and Metohija which was in accordance with similar habitats in the neighboring countries (Rajkovic, 2007; Parvulescu, 2008; Zaikov, 2010; Trožić-Borovac, 2011). It was found that species A. torrentium inhabits mountain streams and small rivers, the source branches of lowland rivers. Water rich in oxygen, moderate to low temperatures and rocky bottom are the characteristics of these habitats. It was found that these watercourses were characterized by an oligo saprobic level of water quality. The site altitude of the distribution of this species was to over 700m. Lowland parts of the investigated rivers were populated with individuals of A.astacus.

The most important habitat of this species was a hydrographic basin of the Sitnica River, the major river of the Kosovo Valley (Fig. 1).

Based on previus research, the water quality of finding sites of A. Astacus was assessed as beta-mezosaprobic (Urošević, 1989; Živić, 1997, 1998). Large expansion of the human population is evident at the investigated area. It is followed by a large urban, industrial and agro-technical change. Therefore, crayfish have reduced and fragmented areals. A.astacus native species and A. torrentium are listed in the Red List (IUCN, 2010) in Europe while their habitats in the Habitat Directive. Therefore, ecosystems that they inhabit in Kosovo require a special conservation approach and research to ensure their protection and biodiversity conservation, similar to other regions in Europe (Fyreder at al., 2004).

 

Conclusion

The undertaken research has shown that the water bodies in the territory of Kosovo and Metohija are populated by native populations of the two species of freshwater crayfish – Astacus astacus and Austropotamobius torrentium. Their presence was confirmed at 33 sites. Individuals of A. torrentium inhabit mountain streams and rivers of oligosaprobic water quality. Populations of A. astacus occupy lowland parts of the rivers with a beta meszosaprobic level of water quality. Site altitude of the distribution of this A. torrentium species was to over 700m. Lowland parts of the investigated rivers were populated with individuals of A. astacus.

 

Fig01
Figure  1: Hydrographic network of crayfish distribution.