LIMB REGENERATION AND SUBSEQUENT ASYMMETRY IN A MALE SECONDARY SEXUALCHARACTER INFLUENCES SEXUAL SELECTION IN WOLF SPIDERS

Males of the brush-legged wolf spider Schizocosa ocreata (Hentz) have conspicuously decorated forelegs used in courtship and agonistic displ ays. Approximately one in five juvenile males has a missing or regener ating foreleg, and regeneration of a leg lost during development usual ly results in the absence of a decorative tuft on that leg. The subseq uent asymmetry in this male secondary character significantly decrease s success in both courtship of females and male-male agonistic interac tions. Experimental removal of tufts from one leg of previously succes sful symmetric males produces similar results. As a test for concomita nt behavioral effects, female spiders were shown video images of a cou rting male with symmetric tufts and the same video image altered to ha ve asymmetric tufts. Female receptivity to the asymmetric video image was lower. In contrast to fluctuating asymmetry resulting from develop mental instability, leg tuft asymmetry in S. ocreata most likely arise s from a single event during ontogeny - possibly leg loss from an aggr essive or predator encounter and may serve as a quality indicator in f emale mate choice.