Tasserkidriluscf.americanus (Clitellata, Naididae) - A new record from Slovakia confirms the dissimilarity between the European and North American populations.

Igor Kokavec

doi:10.3897/bdj.9.e72846

Abstract

The main objective of this study is to present a new record of Tasserkidriluscf.americanus found in a channel near the Tešmak swamp in Slovakia (Central Europe) and to compare its morphological features and habitat requirements with those of populations occurring in North America and Europe. The new specimens are similar to those found in The Netherlands and Belgium, but dissimilar to previously reported North American material of T.americanus, reopening the question of whether the European form is a separate species. The European form has the penis sheaths approximately twice as long as and wider than the North American form and may inhabit slow-flowing or standing waters of a eutrophic character, which is in conflict with the current knowledge on the morphology and ecology of North American populations. Further investigation is necessary to solve the questions about the origin and taxonomic relationship of the European population to other populations.

Highlights

At present, the genus Tasserkidrilus Holmquist, 1985 includes 14 freshwater species, all in the Holarctic Region (Table 1)
In Europe, frequent records of T. cf. americanus in streams have been documented from Belgium and The Netherlands
The present finding of the species from Slovakia has reopened the discussion about the origin, distribution and taxonomy of the European population

Summary

Introduction

The genus Tasserkidrilus Holmquist, 1985 includes 14 freshwater species, all in the Holarctic Region (Table 1). 11 were recorded in the Palearctic Region, of which nine species are endemic to Lake Baikal and one species is endemic to the Kamchatka Peninsula. Despite high endemism of the genus, there are two species, T. americanus (Brinkhurst & Cook, 1966) and T. kessleri (Hrabě, 1962), which have a more scattered distributional pattern, occurring in several countries in both Eurasia and North America. Overview of the representatives of the genus Tasserkidrilus; 1disputable occurrence in the Lake Baikal (see Semernoy (2001)), 2 according to WoRMS (2021), 3 probable misidentification (see Semernoy (2001)) Valid name.

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