Morphological Comparison of the Malleoli (Racquet Organs) in Biton zederbaueri and Gluviopsilla Discolor (Daesiidae, Solifugae)

Abstract

The detailed morphology of the malleoli in two male solfugids, Biton zederbaueri (Werner, 1905) and Gluviopsilla discolor (Kraepelin, 1899), (Daesiidae, Solifugae) arc described and illustrated. This study was performed using stereo and scanning electron microscopy (SEM). Solifuges have five pairs of malleoli on the ventral surface of the fourth pair of legs of both sexes, as distinct from other arachnids. Malleolar sensory systems function as mechanoreceptors and chemoreceptors. A malleolus consists of two parts: a basal stalk and a triangular fan. There are epicuticular protrusions on the anterior face of each fan, and there are granular/vesicular structures on each stalk. Also, there are waved surfaces on the distal of the fan. This is the first study on the morphology of malleoli in solifuges in Turkey.