Marie Curie Actions: Inspiring Researchers - Imdea

One simple strategy involves the males simply guarding afemale they have mated with, fi ghting off any other males thatattempt to get near her.Kinky stuffIn many species, the males ‘plug’ the female’s sexual orifi ces bybreaking off all or part of their own sex organs during intercourseand leaving them behind in the female. The males of somespecies actually castrate themselves entirely during this process,becoming eunuchs. By sacrifi cing a body part in this way, themales hope to stop the females from being able to mate withother males. However, the story does not end there, becausethe females have changed the size and shape of their own sexorgans to allow them to accommodate these plugs while stillmating with other males!The spiders are now engaged in an evolutionary ‘arms race’.Dr Kuntner’s research shows that in some species the maleshave the upper hand as the plugs seem to be completelyeffective at stopping the females from mating. However, in othernephilids, the females have retained control over their sex lives,and can mate a number of times despite having several plugsembedded in their sexual organs.Dr Kuntner has even observed cases of post-coital cannibalism.The females of the species involved, Herennia multipuncta, arenotoriously sexually aggressive. In these cases, the male mayplug an aggressive female in a bid to monopolise her sex organsbefore he is either evicted or eaten.This research has challenged and altered the mainstreamviews of the scientifi c community. Prior to this project, sexuallyantagonistic co-evolution had been demonstrated in insects butnot in spiders. The results are an important contribution to theunderstanding of sexual selection mechanisms.Let’s talk it overEncouraged by a receptive public, Dr Kuntner has enthusiasticallyinvested time and energy into communicating the results ofhis work. He gives regular talks on spiders, and has set up awebsite devoted to his favourite arachnids. In addition to detailsof both past and current research projects, it features many246