Does sexual size dimorphism vary with female size in forest millipedes Centrobolus Cook, 1897?

Abstract

This study aimed to determine whether the variation responsible for breaking Rensch's Rule when Sexual Size Dimorphism (SSD) increased with body size was due to male-biased or female-biased variation by studying a sex-based set of morphological characters. Variation in female volume based on length and width measurements was associated with the SSD in the forest millipede genus Centrobolus. There was a significant positive correlation between SSD and female size (r=0.56, Z score=2.76, n=22, p<0.01). The correlation coefficient between SSD and female size did not differ significantly from the correlation coefficient between SSD and species size (z-statistic=-0.7078, p=0.4790). The morphological differences among the polygynandrous reproductive systems occurring in Centrobolus with higher SSD and larger females were discussed.