Occurrence and Habitat Preferences of the Euryhaline Oligochaete Paranais litoralis (Müller, 1784) (Clitellata: Naididae) in a Tributary of the Danube River Middle Stretch.

Paranais litoralis, a euryhaline aquatic oligochaete, was recently recorded in the middle stretch of the Danube River basin. This study provides more details about population abundance and habitat preferences of the species, inhabiting a lowland stretch of the Váh River in Slovakia. For the first time, few specimens were identified at one sampling site in September 2015, whereas in May 2016 the species was found at three sampling sites, with abundance ranging from 86 to 614 individuals per square meter. Regarding its habitat distribution, P. litoralis prefers sandy substrata but occurs also on muddy and stony substrata. The possible origin of this isolated population is discussed. [ABSTRACT FROM AUTHOR]