Re-assessment of rensch’s rule in Centrobolus

Abstract

Sexual size dimorphism (SSD) was investigated in the helminthomorph genus Centrobolus (=Chersastus). Width, length and mass were used to compare the interspecific variation for 20 species. Interspecific variation in volume was calculated in these species and an allometric coefficient of 0.7 found. The allometric equation generated for the genus also the inverse of Rensch’s rule as there was a positive correlation between SSD and body size (R=0.70485; P=0.00109; n=18 spp) in this diplopod genus. This SSD is thought to have evolved through intersexual competition driven by sexual selection.