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Ant antennae: are they sites for magnetoreception?
Jandira Ferreira de Oliveira1, Eliane Wajnberg, Darci Motta de Souza Esquivel
1Fakultät für Chemie-FG Elektronenmikroskopie-Technische Universität München, Lichtenbergstr. 4, 85747 Garching, Germany. jandiuff@cbpf.br
Journal of the Royal Society, Interface
|May 29, 2009
Summary
The Pachycondyla marginata ant uses magnetic iron minerals in its antennae to sense direction. These minerals, likely soil particles, are located near sensory organs, enabling navigation along the geomagnetic field.
Area of Science:
- Zoology
- Biophysics
- Geomagnetism
Background:
- The migratory ant, Pachycondyla marginata, exhibits orientation aligned with the geomagnetic north-south axis.
- Previous studies suggested antennae house the magnetoreceptor responsible for this navigational ability.
Purpose of the Study:
- To identify iron (Fe(3+)/Fe(2+)) sites within the antennae of Pachycondyla marginata.
- To elucidate the composition and location of magnetic materials potentially involved in the ant's magnetoreception.
Main Methods:
- Light microscopy with Prussian/Turnbull's blue staining to detect iron.
- Transmission electron microscopy (TEM) for imaging and diffraction analysis.
- Elemental analysis to determine mineral composition within antennae tissue.
Main Results:
- Ultra-fine-grained crystals of magnetite/maghaemite, haematite, and goethite were identified in antennae joints.
- Aluminosilicates and Fe/Ti/O compounds were also present, suggesting incorporation of soil particles.
- Magnetic materials were found associated with Johnston's organ and other antennal joints.
Conclusions:
- The identified magnetic minerals in the antennae are likely incorporated soil particles, not biomineralized.
- The concentration of magnetic material near sensory structures supports a role in magnetic-field-modulated mechanosensory input.
- This mechanism likely underlies the magnetic sense crucial for the migratory ant's navigation.
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