Fifty Shades of Spiders
Sex in spiders is unique in the animal kingdom and rife with sexual cannibalism, genital mutilation, female choice, gustatory courtship, multiple modes of seduction, and extreme differences in the sizes of the sexes. These traits, and their major evolutionary consequences, make the study of sex in spiders one of the richest areas of research in behavioral arachnology. Female spiders are predators, even in courtship and mating. A male spider must not only persuade a female that he is the finest male that she is likely encounter, but also that she shouldn't eat him.”
Much of male spider morphology and behavior is designed to reduce their risk of being cannibalized by the female. Most males are significantly smaller than their mates, some as much as one hundred times smaller. This great difference in size can help the male escape with his life.
Image above shows a mating pair of spiders as captured in Linda Rayor's lab.