Abstract. Temperature changes are among the most powerful causes of disturbed embryogenesis in spiders. They are responsible for body deformities which impede development of these animals and lead to their death long before they reach sexual maturity. The main objective of this study was to show the relationship between the applied teratogenic factor and embryo mortality as well as morphological deformities in Eratigena atrica (C. L. Koch, 1843). Developmental abnormalities were induced by temperatures of 14 and 32°C, changed every 12 hours for the first 10 days of embryo development. As a result, we obtained 78 deformed specimens, including 8 with the fusion of a pedipalp and the first walking leg (heterosymely). Several spiders were additionally affected by oligomely (absence of legs) or schistomely (bifurcation of legs). Since we obtained a relatively large group of larvae with heterosymely of a pedipalp and the first walking leg (in different combinations) we aimed at showing the diversity of this deformity. The morphology of these individuals is described in detail and presented in figures.