Abstract:
A peculiar array of over 1000 cuticular pits is found ventrally and laterally on the posterior
segments of metasoma and telson of a few taxa of Buthidae (Scorpiones), including all
species of the widespread Old World desert genus Orthochirus Karsch. SEM
investigation shows those pits adorned with variable size setae, which exhibit
microanatomical features characteristic for chemoreceptors (curved shape, end pore).
Observations in nature (Central Asia) show an unusual in scorpions rest/defense posture
in Orthochirus, with metasoma pressed flat to the mesosoma, its small telson folded
dorsally in a groove, and the ventral surface of the metasomal segment V forming a
“face shield”. We suggest that the up-and-forward facing ventral/lateral surfaces of the
posterior metasomal segments in Orthochirus and related genera could be used as a
chemo-sensory array, analogous to insect antennae.