Cause The Players Gonna Play, I'm Just Gonna Shake: Soliciting Behavior In A South American Spider

BOLLATTI, F.; PERETTI, A. V.; AISENBERG, A.

Congreso; 57th Annual Conference of the Animal Behavior Society (Virtual Meeting); 2020

Animal Behavior Society

A. senex is a sex-role reversed spider in which females are highly activeduring the pre-copulatory phase, but also during mating. Females shake the bodyduring copulation to induce more males? ejaculations. We tested if this femalebehavior is related to body traits in both sexes, to male´s mating behavior andsperm transfer. We estimated individuals´ body condition by measuring body sizeand weight. We recorded both sexes behaviors during 20 sexual encounters andcounted the sperm rests in the males pedipalps. Female? shakes were positivelyexplained by female´s age (χ2=9,718; p=0.002), by their body condition (χ2=10.087; p=0.002) and that of males (χ2=19.662; p<0.01).The males showed less sperm in the palp when the female made less body shakes (χ2=5,389; p=0,020). Females were more demanding when they were older,maybe because their fertile life span is reducing. Larger females also performmore shakes, because its possibly higher fertility. Females demanded moreejaculations to larger males, perhaps because it is an honest good genes´ signal.The body shakes that A. senex females performed occur not just whenmales make less ejaculations, but also when they transfer less sperm.