Tusks sense chemicals: Narwhal
The tusks of male narwhals may detect chemicals related to ice formation, salinity, or prey using a vast network of fluid-filled tubules connected to the tusk's central nerve.
|Process information >|
|Sense signals/environmental cues >|
|Chemicals (odor, taste, etc.)|
|Biomimetic Application Ideas|
|Chemical sensors for water quality control purposes, sensors to alert officials to changes in recreational water quality, pollution control mechanisms for shipping ballast water.|
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"Now Martin Nweeia at Harvard School of Dental Medicine and his colleagues have come up with another explanation. They believe the tusk, which can measure up to 2.75 metres, could act as a sensor, helping the narwhal to survive in its Arctic home by detecting chemicals associated with prey, ice formation and salt concentrations.
"Two tusks taken from recently caught narwhals were examined under an electron microscope. This revealed a vast network of around 10 million fluid-filled tubules connecting the tusk's central nerve to the surrounding water. Such tubules exist in human teeth, but are only exposed at areas of gum recession, where they cause extreme sensitivity. 'The last place you would expect to have something so sensitive is a cold Arctic environment,' says Nweeia. A further surprise came when a laser was used to map the chemical composition of the tusk, a technique called reflectance microspectroscopy. It revealed that the narwhal's tusk is 'inside out'. Most teeth are hard on the outside and soft inside, but the narwhal's tusk has a soft protein-rich exterior, while the inside is more mineralised. 'Everything about these findings is counter-intuitive,' says Nweeia." (Geddes 2005:6)
Monodon monoceros Linnaeus, 1758
IUCN Red List Status: Near Threatened
Habitat(s): Marine Neritic, Marine Oceanic
Natural History Information: Watch video (informative video for children)
Some organism data provided by: ITIS: The Integrated Taxonomic Information System
Organism/taxonomy data provided by:
Species 2000 & ITIS Catalogue of Life: 2008 Annual Checklist
Application Ideas: Chemical sensors for water quality control purposes, sensors to alert officials to changes in recreational water quality, pollution control mechanisms for shipping ballast water.
Industrial Sector(s) interested in this strategy: Sensors, public health, pollution control