Long-duration whirling of Pholcus phalangioides (Araneae, Pholcidae) is specifically elicited by Salticid spiders.

Long-duration whirling (gyrating of the body during several hours a day) was shown by the pholcid spider Pholcus phalangioides to salticid spiders and hardly ever to predatory spiders from eight other families in laboratory arenas. Long-duration whirling has not been reported so far, in contrast to short-duration whirling lasting less than a few minutes. Long-duration whirling may have the anti-predatory function of disturbing continual visual fixation of prey in attacking salticids, in contrast to short-duration whirling that has been demonstrated to favour survival of pholcids in the presence of all sorts of predatory spiders.