Non-indigenous invasive freshwater crustaceans (Crustacea: Malacostraca) in Slovakia - page 5

Echinogammarus ischnus (Stebbing, 1899) is a Ponto-Caspian species known from the Slovak section of the Danube River since the 1950s (Figure 8) (Brtek, 1953; Brtek and Rothschein, 1964). The species extended its range upstream and is to be found in the Austrian section of the Danube (Nesemann et al., 1995). The main route of dispersion for this species is the Central corridor (Bij de Vaate et al., 2002).

Echinogammarus trichiatus (Martynov, 1932) is one of the most recent non-indigenous species occurring in the Slovak and Hungarian section of the Danube (Figure 9). The first record of the species for Slovakia is published by Borza (2009). The species occurs in the upper section of the Slovak Danube River reaching up to city of Rajka (Hungary) so far.

 

Fig08
Figure 8: Distribution of E. ischnus. Triangles indicate the occurrence of the species recorded in the research in 2011, data from Brtek (2001) (squares) and Elexová et al. (2010) (circles).

 

Fig09
Figure 9: Distribution of E. trichiatus confirmed by Borza (2009) (indicated with diamonds). Black triangles indicate the occurrence of the species confirmed in the research in 2011.

 

Obesogammarus obesus (Sars, 1894) is native to the lower part of the Danube River and its native range of occurrence has been as far up as Serbia (Nesemann et al., 1995; Brtek, 2001; Nehring, 2006). Like other species of the Ponto-Caspian amphipods, O. obesus began to move upstream the Danube River (Bij de Vaate et al., 2002). The species was later found in the Rhine River, arriving there through the Main-Danube Canal in 2004 via ship traffic (Nehring, 2006). The first record for Slovakia was published by Šporka and Elexová (1999). The current distribution of the species is demonstrated in Figure 10.

 

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Figure 10: Distribution of O. obesus according to Brtek (2001) (squares), Borza (2009) (diamonds) and the research conducted in 2011 (triangles).