Sexual cannibalism in spiders

Gone fishin’

ANIMAL mating can be a cruel and unusual process. Male bedbugs inseminate females by piercing their bellies and depositing sperm inside their paramours’ body cavities. Male chimpanzees and lions kill the suckling infants of females before mating with them, as this brings those females more rapidly into oestrus. Male dolphins routinely engage in rape. Nor are aggressive mating practices perpetrated solely by males against females. In many species of insects and spiders, females eat their partners after sex.

Such cannibalism clearly brings advantage to the female, who gets an easy snack. But the benefits (if any) for the male are less obvious. That there might sometimes be such benefits, though, is an idea that intrigues zoologists—and so, from time to time, some of them look into the matter.

The latest to do so are Steven Schwartz of Gonzaga University, in the American state of Washington, and Eileen Hebets of the University of Nebraska-Lincoln. Dr Schwartz and Dr Hebets note that, after mating, the males of one species of arachnid, the dark fishing spider, spontaneously die and thus ensure…Continue reading
Source: Economist