First record of the invasive Ponto-Caspian mysid Limnomysis benedeni Czerniavsky, 1882 from the River Pripyat, Belarus

The invasive Ponto-Caspian mysid Limnomysis benedeni Czerniavsky, 1882 has been recorded for the first time in August 2007 at three sites on the River Pripyat (the Belarusian part of the inland European central invasion corridor). This species occurs in the onshore shallow zone (depth 0.2-0.3 m) with aquatic vegetation and high temperature. High abundances of this species have been observed in port bays. Most likely, this invasive mysid entered the River Pripyat basin from the Dnieper Reservoirs where it was intentionally introduced after 1960.

Until now only two mysid crustaceans, Mysis relicta Lovén, 1862 and Paramysis lacustris (Czerniavsky, 1882), have been reported from Belarusian inland waters.M. relicta, a native glacial relict species, has been recorded from some lakes of glacial origin in the hypolimnion layer (Suschenya et al. 1986).During 2006 a Ponto-Caspian mysid P. lacustris was found in Lake Drysviaty, a cooling reservoir of Ignalina nuclear power station (Vezhnovetz, unpublished data, Annex).This species entered into this lake from Lithuania where it was intentionally introduced in 1960s (Arbačiauskas 2005).
In August 2007 another invasive Ponto-Caspian mysid, Limnomysis benedeni Czerniavsky 1882 was found in hand net samples taken during a survey of the River Pripyat (Figures 1-2, Annex).A typical biotope, where L. benedeni was found, is the onshore shallow zone (depth 0.2-0.3m) with aquatic vegetation (Ceratophyllum spp.and Potamogeton spp.) and high temperature (25-26 o C).Oxygen content and pH in the biotopes were between 4.3-7.2mg l -1 and 7.47-7.57,respectively.The conductivity was low and did not exceed 174 µS.
Maximal abundance (176 ind.m -3 ) of L. benedeni was recorded in the canal which connects Mykashevichy port bay with the river.This species was also found in Mozyr port bay (12.8 ind.m -3 ) and the lower part of the river near Narovlia town (19.2 ind.m -3 ) (see Figure 1 and Annex).
Limnomysis benedeni is a typical species of freshwater and brackish waterbodies in the Black Sea and Azov Sea regions.Usually it prefers less than 5 PSU salinity and macrophyte biotopes (Mordukhai-Boltovskoy 1969).
Limnomysis benedeni is a typical species of freshwater and brackish waterbodies in the Black Sea and Azov Sea regions.Usually it prefers less than 5 PSU salinity and macrophyte biotopes (Mordukhai-Boltovskoy 1969).
In the middle of the 20th century, L. benedeni was intentionally introduced into the Dnieper Reservoirs and Balaton Lake in order to increase the food source of young fish (Mordukhai-Boltovskoy 1969).This species also entered in the middle part of the Danube River on Serbian territory (Bogut et al. 2007) and the Rhine River (Bernauer and Jansen 2006).Intensive shipping along inland waterways via the Dniepr and Pripyat Rivers can most likely be considered as the main pathway of invasion of L. benedeni into the Prypyat River from the reservoirs in the Dniepr River, as indicated by records of this species in locations close to river ports.In this regard it is necessary to point out that Mazyr and, especially, Mykashevichy ports are characterized a high intensity of barge shipping.
It is probable that P. lacustris will also be found in other lakes and rivers near the Lithuanian border as this species is found in the Neman River basin on Lithuanian territory adjoining Belarus (Arbačiauskas 2005).
Limnomysis benedeni has a short life span and generation time, non-specific food preference, and suspension feeding (Bogut et al. 2007).Present records of L. benedeni in high densities in several locations in the Pripyat River may indicate that this invasive Ponto-Caspian species is successfully established in inland waters of Belarus, and further studies are needed to estimate its impact on the native communities in Belarus, as well as survey of it possible further dispersal along the European central invasion corridor to the basins of the Bug and Vistula Rivers (Poland).