Fig. 1
From: Material composition and mechanical properties of the venom-injecting forcipules in centipedes
Scolopendra oraniensis and experimental setup and results from breaking force/stress experiments on Scutigera coleoptrata, Lithobius forficatus and Cryptops hortensis. A Head and anterior trunk of Scolopendra oraniensis in dorsolateral view. The forcipule is composed of coxosternite, trochanteroprefemur, femur, tibia and tarsungulum (proximal to distal). Arrow points to shared joints of trochanteroprefemur, femur, tibia and tarsungulum. B Experimental setup. The forcipule is embedded in epoxy and the tarsungulum is in a straight, free-standing position. The force transducer is lowered onto the tip of the tarsungulum. C Longitudinal-section through the forcipule of L. forficatus (microCT). The arrows point to the venom channel. C’ Cross-section of the tarsungulum of L. forficatus at the point of breakage. Purple area indicates the measured cuticle area used for stress calculations. D Exemplary forcipule of S. coleoptrata after the breaking force/stress measurement. The tarsungulum is not broken, but plastically deformed. E Exemplary forcipule of L. forficatus after measurement. F Exemplary forcipule of C. hortensis after measurement. an antenna. cxst coxosternite. fe femur. ll1 locomotory leg 1. mx2 maxilla 2. om ommatidia. tas tarsungulum. ti tibia. trpfe trochanteroprefemur