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.