Sensing the world without antennae and eyes: external structure and distribution of sensilla in Eosentomon pinetorum Szeptycki, 1984 and on the protarsus of Acerentomon franzi Nosek, 1965 (Hexapoda: Protura)

Abstract

Protura are miniaturized soil arthropods with an enigmatic biology. Among mandibulate arthropods, Protura are outstanding due to the absence of antennae. This study provides the first detailed investigation on external cuticular sensilla in two proturan species using scanning electron microscopy. The fine structure and distribution of cuticular sensilla on the protarsus as well as putative sensory structures on the body surface are described. Distinct differences in quality and quantity are evident between different proturan taxa. Potential consequences of These observations on the proturan biology are discussed.