Original paper

Racial differentiation in Asellus aquaticus (L.) (Crustacea: Isopoda: Asellidae)

Prevorcnik, Simona; Blejec, Andrej; Sket, Boris


The primary patterns of racial differentiation in the water louse, Asellus aquaticus (L.) sensu RACOVITZA, were assessed by the analysis of geographic variation in 59 morphometric characters. Males from 20 localities in Slovenia and 18 in other countries were analyzed. In Multivariate Discriminant Function Analysis, Minimum Spanning Tree and in Cluster Analysis, samples comprising specimens without eye and body pigmentation are separated from the samples with pigmented specimens, even though these two troglomorphic traits are not being considered. Only 7 traits are needed for the separation. In the cline of the samples with pigmented specimens, 3 groups of samples with the concentric distribution ranges may be distinguished. The results confirm the existence of extensive racial diversification in Slovenia and indicate some inconsistencies in the presently applied classification. The results of separate analysis of male gonopod structure are consistent with the results of multivariate statistical analysis.


geographic variationmorphometric analysistroglomorphic traitspigmentationisopodaasellus