Olfaction: underwater 'sniffing' by semi-aquatic mammals

Nature. 2006 Dec 21;444(7122):1024-5. doi: 10.1038/4441024a.


Terrestrial species that forage underwater face challenges because their body parts and senses are adapted for land--for example, it is widely held that mammals cannot use olfaction underwater because it is impossible for them to inspire air (sniff) to convey odorants to the olfactory epithelium. Here I describe a mechanism for underwater sniffing used by the semi-aquatic star-nosed mole (Condylura cristata) and water shrew (Sorex palustris). While underwater, both species exhale air bubbles onto objects or scent trails and then re-inspire the bubbles to carry the smell back through the nose. This newly described behaviour provides a mechanism for mammalian olfaction underwater.

MeSH terms

  • Air* / analysis
  • Animals
  • Feeding Behavior / physiology
  • Fishes
  • Inhalation / physiology
  • Moles / physiology*
  • Odorants / analysis
  • Oligochaeta
  • Respiration*
  • Shrews / physiology*
  • Smell / physiology*
  • Swimming / physiology*
  • Vibrissae / physiology
  • Water* / chemistry


  • Water