Journal ArticleDOI
Biophysics of geomagnetic field detection
TLDR
In biology, the study of geomagnetic orientation has gained new momentum since the discovery of magnetic field detectors in aquatic organisms and the ability of sharks and rays to orient to the earth's magnetic field has been demonstrated in behavioral experiments as discussed by the authors.Abstract:
In biology, the study of geomagnetic orientation has gained new momentum since the discovery of magnetic field detectors in aquatic organisms. Sharks and rays respond to dc and low frequency voltage gradients of 0.005 μV/cm. By moving through the earth's magnetic field, they induce electric fields well within the sensitivity range of their keen electric sense. As these fields depend on the direction in which the animal is heading, the induced voltage gradients may serve as the biophysical basis of an electromagnetic compass sense. The ability of sharks and rays to orient to the earth's magnetic field has been demonstrated in behavioral experiments. Also, various marine and freshwater mud bacteria are endowed with permanent magnetic dipole moments, directed parallel to the axis of motility. When separated from the sediments, these bacteria return to the mud by migrating downward along the earth's inclined magnetic field lines. Their orientation is largely determined by the principles of statistical mechanics and may be expressed in terms of the directive magnetic force, the randomizing effect of thermal agitation, and the cells' flagellar thrust. Observations on live bacteria yield individual dipole moments circa 15 × kT/G.read more
Citations
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Journal ArticleDOI
Structure and function of the vertebrate magnetic sense
Michael M. Walker,Carol E. Diebel,Cordula V. Haugh,P.M. Pankhurst,P.M. Pankhurst,John C. Montgomery,Colin R. Green +6 more
TL;DR: The key components of a magnetic sense underpinning this navigational ability in a single species, the rainbow trout are described and an area in the nose of the trout where candidate magnetoreceptor cells are located is identified.
Journal ArticleDOI
Electric and magnetic field detection in elasmobranch fishes
TL;DR: Dogfish and blue sharks were observed to execute apparent feeding responses to dipole electric fields designed to mimic prey, and stingrays showed the ability to orient relative to uniform electric fields similar to those produced by ocean currents.
Journal ArticleDOI
Movements of blue sharks (Prionace glauca) in depth and course
TL;DR: Acoustic telemetry was used to follow 22 blue sharks,Prionace glauca (Linnaeus), over the continental shelf and slope in the region between George's Bank and Cape Hatteras between 1979 and 1986, finding that they may orient to the earth's magnetic field, or to the ocean's electric fields, allowing them to swim on a constant heading in the absence of celestial cues.
Journal ArticleDOI
Magnetite-based magnetoreception
TL;DR: It is the opinion of the authors that all magnetic field sensitivity in living organisms, including elasmobranch fishes, is the result of a highly evolved, finely-tuned sensory system based on single-domain, ferromagnetic crystals.
Journal ArticleDOI
Magnetoreception in plants
Paul Galland,Alexander Pazur +1 more
TL;DR: Two further mechanisms for magnetoreception are currently receiving major attention: the “radical-pair mechanism” consisting of the modulation of singlet–triplet interconversion rates of a radical pair by weak magnetic fields, and the ”ion cyclotron resonance” mechanism.
References
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Journal ArticleDOI
Magnetite in Freshwater Magnetotactic Bacteria
TL;DR: Results of Mossbauer spectroscopic analysis applied to whole cells identifies magnetite as a constituent of these magnetic bacteria in a previously undescribed magnetotactic spirillum isolated from a freshwater swamp.
Journal ArticleDOI
The Electric Sense of Sharks and Rays
TL;DR: The experiments described demonstrate clearly that the shark Scyliorhinus canicula and the ray Raja clavata make a biologically significant use of their electrical sensitivity and are justified in accrediting the animals with an electric sense and in designating the ampullae of Lorenzini as electroreceptors.
Book ChapterDOI
The Detection of Electric Fields from Inanimate and Animate Sources Other Than Electric Organs
TL;DR: To establish and analyze this role, a basic knowledge of the natural electric fields and the information they provide is an essential prerequisite and whether the information is of biological significance to electrosensitive animals must be determined by appropriate behavioral experiments.
Journal ArticleDOI
Pigeons have magnets
TL;DR: Research on pigeon homing suggests that magnetic field information is used for orientation, and the ability of pigeons to sense magnetic fields may be associated with a small, unilateral structure between the brain and the skull which contains magnetic in single domains.
Journal ArticleDOI
A Method for Determination of Low Carbon Monoxide Concentration in Blood
TL;DR: The results indicate that small amounts of CO may be formed during procedures used for the release of CO from blood, probably due to oxidative break down of hemoglobin.