The first case of gynandry in Mygalomorphae: Pterinochilus murinus, morphology and comments on sexual behavior (Araneae: Theraphosidae)

A bilateral gynandromorph specimen of the tarantula Pterinochilus murinus Pocock, 1897 is here described and illustrated. In addition, encounters with conspecific females were studied. The possible explanations for this case of gynandry are discussed. This constitutes the first formal report of gynandry in a mygalomorph spider.