The timing of insemination and its implications for sperm competition in a millipede with prolonged copulation

Sperm storage organs and their controlling mechanisms were illustrated for Centrobolus inscriptus. The upper reproductive tract with separate insemination duct, spermatheca and oviduct was sectioned. Muscles controlling sperm movement towards the spermatheca were illustrated and identified as muscles of the bursa and gutter apodematique. Sensory apparatus connected to the spermathecae were illustrated.

Section: Discussionmentioning

confidence: 97%

Sperm storage in Centrobolus inscriptus Attems (Spirobolida: Trigoniulidae)

Cooper¹

2016

“…Copulation durations were recorded by isolating mating pairs using plastic beakers (13 cm diameter). The radio isotope labelling technique was used to record and control ejaculate volume [12,25] .…”

Section: Methodsmentioning

confidence: 99%

“…Male mediation of copulation duration is known in the fruitflies Drosophila melanogaster [3][4] and D. montana [5] , firefly Photinus macdermotti [6] , millipede Alloporus uncinatus [7] , mite Macrocheles muscaedomesticae [8] , spiders Hogna helluo [9] and Argiope keyserlingi [10] , praying mantid Ciulfina 2 , and soldier fly Merosargus cingulatus [11] . Female mediation is known only in the millipede Alloporus uncinatus [12] . Numerous species of millipede can coexist in sympatry [13][14][15][16][17] .…”

Section: Introductionmentioning

confidence: 99%

Fire millipedes obey the female sooner norm in cross mating Centrobolus (Myriapoda)

Cooper¹

2016

Sexual mediation of copulation duration is reviewed in arthropods. Copulation duration and ejaculate volume were recorded in cross mating Centrobolus to test species' mediation differences. Conspecific C. inscriptus copulation durations were long (170.0 ± 49.3 min, n = 46), C. annulatus copulation durations were short (39.4 ± 18.6 min, n = 8), while mating between heterospecifics (C. inscriptus X C. annulatus) had the shortest copulation durations (12.4 ± 10.6 min, n = 6); when re-mating interval, sexual size dimorphism, sex ratio and ejaculate volume were controlled. âº (the female sooner norm) suggests sizeassortative mating without a size based preference in these mate-guarding millipedes.

“…The only alternative hypothesis is the possible prevention of rival ejaculates from competing with sperm already donated to a partner. Sperm displacement may take the form of self-sperm displacement or mixing as was demonstrated in Alloporus uncinatus [13] . In the Diplopods the most competitive hypothesis is for mate guarding (to protect an already donated ejaculate).…”

Section: Introductionmentioning

confidence: 93%

“…Of the diversity of post-insemination associations between the sexes in the insects [1] , prolonged copulations dominate in the diplopods [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] . In most species, males maintain genital contact far beyond the time needed only for insemination of the female.…”

Section: Introductionmentioning

confidence: 99%

Post-insemination associations between males and females in Diplopoda: A remark on Alcock’s (1994) predictions of the mate-guarding hypothesis

Cooper¹

2016

Here I review the most common form of mate-guarding (prolonged copulation) in the Diplopoda. The ten predictions for mate-guarding in Insects are compared using Diplopod examples and evidence in favour of 7 of Alcock's (1994) predictions (1, 2, 3, 4, 5, 6, 8) was found. Future research on mate-guarding in the Diplopoda may test 2 untested predictions (7 and 10). The last prediction (9) cannot be tested as millipedes are non-territorial.