Student Research Projects

EDS-based Investigation of the Elemental Composition of the Exoskeleton of A Harvestmen

Student Alison Washington '15
Faculty Mentor(s)
Department Biology
Course Biology 400: Scanning Electron Microscopy (SEM)


Metals such as copper, iron, zinc and manganese are frequently incorporated into the exoskeleton and cuticular structures of arthropods. Although iron and zinc have been found in the claws and fangs of spiders and scorpions, previous studies of harvestmen have only identified manganese. In this study, I examined elements present in the tergite and pedipalp of Glysterus sp. I used the Oxford EDS system at accelerating voltages of 10 kV and 30 kV. I found iron, calcium, and molybdenum in the large spine on the second tergite and in the tip of the claw of the pedipalp at the accelerating voltage of 10 kV but not at the accelerating voltage of 30 kV. This result indicates that iron is present near the surface only in these structures. This is the first observation of the incorporation of iron in the integument of harvestmen. In the future, I intend to observe examine other body parts and regions, i.e., tarsal claws on leg IV and chelicerae.