Wolf spiders lack mirror-image responsiveness seen in jumping spiders

Abstract

Many jumping spiders (Salticidae), having good acuity and feature recognition mechanisms, display toward their mirror image. Since there was evidence for visually based communication in some wolf spiders (Lycosidae), mirror-image responsiveness was tested in four species of wolf spiders. Schizocosa ocreata and Lycosa rabida were expected to be more responsive than S. saltatrix and L. punctulata, the former two species having ornamented appendages used during display. However, none of these lycosids showed salticid-like orientation or display toward the mirror image. Yet, a moving male in a nearby acoustically isolated cage elicited orientation and, in many cases, approach or display in males of all four species. Apparently, wolf spiders must be motionless to respond visually to conspecifics, which relates to their sit-and-wait mode of prey capture and their reciprocal signalling during courtship. Unlike jumping spiders, wolf spiders seem unable to analyse retinal input consisting of a moving image against a background image that is moving due to the spider's locomotion.