Mark Cooper School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg 2050, South Africa Arthropods ISSN 2224-4255 http://www.iaees.org/publications/journals/arthropods/online-version.asp 2020 9 2 63 67 International Academy of Ecology and Environmental Sciences Hong Kong 14 August 2019 25 September 2019 1 June 2020 arthropoda copulated mated time variance variation Centrobolus typically has prolonged copulation as a form of syn-copula mateguarding. Variations in the copulation duration were calculated and analysed in four species of the millipede genus Centrobolus. Mean copulation durations differed between all four species but only two species were different intra-specifically. C. inscriptus was different from C. anulatus in copulation duration coefficient of variation (CV) (F=0.41490, d.f.=114, 7, p=0.04892) and C. fulgidus and C. anulatus were different in copulation duration CV (F=0.38912, d.f.=50, 7, p=0.04836). Copulation duration was variable intra-specifically but tends to be intermediate and determining evolutionarily (interspecifically). Copulation duration was significantly correlated (Spearman's Rho Calculator) with male and female volumes (r=1, p=0, n=4, 4; 4, 4). When I controlled for sex, I found copulation duration was significantly correlated with size (volumes) (r=0.6655, r2=0.4429, p=0.004897, n=8, 8). Larger male and female body size correlate with copulation duration both intra-specifically and interspecifically in millipedes, and perhaps in animals. http://www.iaees.org/publications/journals/arthropods/articles/2020-9(2)/zoomorphic-variation-with-copulation-duration-in-Centrobolus.pdf