Locomotor activity and related morphological traits in three millipede species (Diplopoda: Julida)

Abstract

Millipedes (class Diplopoda) represent common members of soil fauna in many ecosystems. They are usually cylindrical or flattened, also characterized by two sets of legs per segment. The relationship between locomotion and morphology has been thoroughly investigated in many arthropods. However, in millipedes, previous studies were mostly based on the influence of different environmental factors on their locomotor activity. The aim of the present study was to analyze the relationship between locomotor activity and morphological variability of body features (body length, body mass), walking legs, and antennae in three European julids, Pachyiulus hungaricus (Karsch, 1881), Megaphyllum unilineatum (C. L. Koch, 1838) and M. bosniense (Verhoeff, 1897). Locomotor activity was videotaped by a web-camera during 15- minute periods and analyzed by ANY-maze software. Antennae and legs were photographed, and their size and shape were estimated using geometric morphometric approach afterwards. Obtained results point out that the evident difference in measured morphological traits among analyzed millipede species significantly determinates their locomotor activity. Moreover, the relationship between locomotor activity and morphological traits is both species-specific and sex-specific.