Teratological deformities of pedipalps in the Tegenaria atrica spider, induced by low and high temperatures applied alternately

•.Alternating temperatures of 14 and 32 °C were used as a teratogenic factor.•Temperature causes mortality increase of spider’s embryo and anomalies formation.•Pedipalpal metamere and its appendages undergo different malformations.•There were 25 larvae with pedipalp deformations.

The study was aimed at demonstrating the relationship between temperature (as a factor which disturbs morphogenesis) and deformities in the front part of the prosoma in Tegenaria atrica. By exposing spider embryos to alternating temperatures of 14 and 32 °C for the first 10 days of embryonic development, i.e. until the first metameres of the prosoma appeared on the germ band, we obtained individuals with a range of anomalies including those which affected the prosomal morphology. We selected five spiders with deformities of pedipalps or of pedipalps and walking legs for comprehensive analysis. The results indicate a relationship between temperature applied as a teratogenic factor and anomalies in the front part of the prosoma.