Superparamagnetic Magnetite in the Iron Granules of Honeybees (apis Mellifera)

Magnetoreception and iron biomineralization in honeybees (Apis mellifera) have been investigated for several decades. Numerous open questions are still been hotly debated, especially the location of superparamagnetic magnetite. To solve this argument, we use the size-density purification technique to purify the iron granules of trophocytes and determined their magnetic properties, which included magnetism by superconducting quantum-interference device magnetometers, magnetic domain by atomic force microscope and magnetic force microscope, as well as ironic valence by electron paramagnetic resonance and electron spectroscopy for chemical analysis. Taken together these results show that superparamagnetic magnetite and FeOOH are clearly present in iron granules of trophocytes. This research clearly confirms that superparamagnetic magnetite is present in iron granules, and reasonably establishes a clear link between iron biomineralization and magnetoreception.