Teratological changes on the prosoma of Eratigena atrica spiders caused by alternating temperatures

Environmental temperature has a tremendous impact on many areas of spiders' lifestyle. It can also be a strong teratogen. The study presents the results of teratological research involving embryos of Eratigena atrica spiders. It was aimed at demonstrating a relationship between the temperature of embryo incubation and the mortality of embryos as well as the number of individuals with body deformities. The experiment was based on the application of alternating temperatures as a teratogenic agent. E. atrica embryos were exposed to temperatures of 14 and 32 ºC changed every 12 h for the first 10 days of their development. We observed that these alternating temperatures significantly influenced embryo mortality and the number of body deformities. Embryo mortality was high and the experimental group contained 40 individuals with different anomalies of the prosoma: oligomely, schistomely, heterosymely, symely and bicephaly. Four individuals were affected by so-called complex anomalies, (combination of several defects). Complex anomalies of appendages on the prosoma were recorded for the first time in the history of our research. Since each case was different, we analyzed and described each of the spiders separately.