Allometry of copulation in worm-like millipedes

Abstract

The prediction that copulation duration is longer when body mass increases was tested in juliform millipedes at the population-level by tabulating and correlating body mass (0.6-8.5g; n=1167) with copulation duration (34-206 min; n=391) in 8 southern African taxa: ord. Spirostreptida fam. Odontopygidae gen. Odontopyge (n=2spp.), Spinotarsus (n=1sp.) and fam. Spirostreptidae gen. Calostreptus (n=1sp.), Doratogonus (n=1sp.); and ord. Spirobolida fam. Trigoniulidae gen. Centrobolus (n=3spp.) collected in 1989 (Zimbabwe) and 1996 (South Africa). Copulation duration and body mass were positively correlated across populations (r=-0.7626, N=11, P=0.006347) and species (r=0.632; N=8; P=0.092734). This study contributes to the allometry of copulation.