Author
Mark Ian Cooper
Bio: Mark Ian Cooper is an academic researcher. The author has contributed to research in topics: Sexual dimorphism & Millipede. The author has an hindex of 12, co-authored 43 publications receiving 437 citations.
Topics: Sexual dimorphism, Millipede, Mating, Biology, Spirobolida
Papers
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TL;DR: Sexual Size Dimorphism (SSD) was investigated in the millipede genus Chersastus and an allometric coefficient of 0.85 found corroborates Rensch’s rule in this genus.
Abstract: Sexual Size Dimorphism (SSD) was investigated in the millipede genus Chersastus. Mass, length and width were used to compare intraspecific variation in four species. Interspecific variation in volume was calculated in 18 species and an allometric coefficient of 0.85 found, which corroborates Rensch’s rule in this genus.
27 citations
TL;DR: In this paper, the authors found evidence of a conflict of interests over control of copulation duration in Centrobolus inscriptus and found that female girth was positively correlated with the second copulation length.
Abstract: Centrobolus inscriptus provides evidence of a conflict of interests over control of copulation duration. Copulation in C. inscriptus lasts for 173 ± 41 min. The re-mating interval between double matings was not impacted by the first copulation duration but was negatively related to the second copulation duration, so that when a female endured a long interval the following copulation was shorter. Female girth was positively correlated to the second copulation duration. The first copulation duration was not significantly dependent on the sexual size dimorphism within copulating pairs, but the second copulation durations was. In these matters of physical combat, the relative sizes of the combatants are thought to be of primary importance.
24 citations
TL;DR: Preliminary evidence for sexual bimaturism in arthropods is found in the sexually size dimorphic genus Centrobolus intergenerational sexual differences in body size was examined in a population of C. inscriptus.
Abstract: Millipedes haverndeterminate growth and adult body sizes are fixed. In the sexually sizerndimorphic genus Centrobolus intergenerational sexual differences in bodyrnsize was examined in a population of C. inscriptus. Millipedes werernmeasured with minimum measurement error and volumetric body size calculatedrnaccording to l.π.r2. Four male and five female stadiarnwere detected in the population and figured. One evolutionary explanation forrnthe extra female stage is fecundity selection for larger female size. This isrnpreliminary evidence for sexual bimaturism in arthropods.
22 citations
TL;DR: Sexual size dimorphism was calculated in 18 species of the genus Centrobolus and illustrated as a regression as females are larger than males and the approximate relative position of C. inscriptus is shown.
Abstract: Millipedes illustrate reversed sexual size dimorphism (SSD) as females are larger than males. SSD was calculated in 18 species of the genus Centrobolus and illustrated as a regression. The approximate relative position of C. inscriptus is shown. The size of C. inscriptus was 2245mm3: 1841 mm3: (females: males; n=88) and logged (x = 3.351216; y = 3.265054) and plotted. The mean volume ratio for C. inscriptus was 1.219446. Sexual size dimorphism was visible with the naked eye.
20 citations
TL;DR: Studies on Centrobolus spp.
Abstract: Studies on Centrobolus spp. were reviewed in which mechanisms of selection, sperm competition and cryptic female choice were studied. Approaches (1) quantify size dimorphism and find the selection pressures operating on the sexes, (2) determine the functional significance of male and female genitalia, (3) understand why there should be a conflict of sexual interests in prolonged copulations, and (4) resolve the mechanisms of sperm competition and cryptic female choice in comparing male mating strategies to female sperm usage were included.
18 citations
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64 citations
TL;DR: In this paper, the authors found evidence of a conflict of interests over control of copulation duration in Centrobolus inscriptus and found that female girth was positively correlated with the second copulation length.
Abstract: Centrobolus inscriptus provides evidence of a conflict of interests over control of copulation duration. Copulation in C. inscriptus lasts for 173 ± 41 min. The re-mating interval between double matings was not impacted by the first copulation duration but was negatively related to the second copulation duration, so that when a female endured a long interval the following copulation was shorter. Female girth was positively correlated to the second copulation duration. The first copulation duration was not significantly dependent on the sexual size dimorphism within copulating pairs, but the second copulation durations was. In these matters of physical combat, the relative sizes of the combatants are thought to be of primary importance.
24 citations
TL;DR: Preliminary evidence for sexual bimaturism in arthropods is found in the sexually size dimorphic genus Centrobolus intergenerational sexual differences in body size was examined in a population of C. inscriptus.
Abstract: Millipedes haverndeterminate growth and adult body sizes are fixed. In the sexually sizerndimorphic genus Centrobolus intergenerational sexual differences in bodyrnsize was examined in a population of C. inscriptus. Millipedes werernmeasured with minimum measurement error and volumetric body size calculatedrnaccording to l.π.r2. Four male and five female stadiarnwere detected in the population and figured. One evolutionary explanation forrnthe extra female stage is fecundity selection for larger female size. This isrnpreliminary evidence for sexual bimaturism in arthropods.
22 citations