Centrobolus silvanus dimorphism based on tergite width

Abstract

The forest genus Centrobolus of diplopoda belonging to the Order Spirobolida is distributed along the eastern coast of southern Africa. Sexual size dimorphism (SSD) can be explained as sexual selection and fecundity selection. Width and length were analysed in Centrobolus to derive SSD in 22 species. Width size of C. silvanus collected in South Africa was calculated as 47.5 mm (n=8). Male width was 43 mm (μ ± σ; n=1) and female width 54 mm (μ ± σ; n=1). An analysis from data presently available showed average SSD for C. silvanus was 1.25581395 differing from 1 (t=1.52753, p=0.085235; n=6). C. silvanus dimorphism was based on a 11 mm difference in horizontal tergite width. Sexual dimorphism appeared as in C. inscriptus female width which was positively related to copulation duration. Keywords. C. silvanus, horizontal tergite width.