Narwhals

About Narwhals

• Narwhals are medium-sized toothed whales belonging to the Monodontidae family.
  • They differ from other toothed whales as they have no teeth in their mouths.
• Habitat: They spend the winter under sea ice.
  • In spring, they move to inshore waters and spend the summer in coastal waters.
• Distribution: They live in the Arctic Ocean, mainly around Canada, Greenland, Norway and Russia.
• Key Features
  • Size: They can reach around 5 m in length.
  • Appearance: They have stout, torpedo-shaped bodies, a low dorsal ridge, and short paddle-shaped front flippers.
  • Colour: They change colour as they grow older.
    • Newborns are blue-gray, juveniles become blue-black, adults are mottled gray, and old narwhals become nearly all white.
  • Diet: They feed on fish, squid and shrimp.
  • Behaviour: They usually travel in groups and can hold their breath for 25–30 minutes.
  • Tusk: The tusk is a long, spiralled canine tooth that usually develops in males and can grow up to 3 metres long.
    • Females occasionally develop a tusk.
  • Tusk Anatomy:
    • Outer and Inner Layers: The outer layer, called cementum, forms a left-handed spiral.
      • While the inner layer, called dentine, forms a right-handed spiral.
    • Double-Twist Structure: These two layers have opposite twists, which create an internal counterbalance where the inner and outer parts meet.
    • Strength and Stability: This arrangement creates internal tension and helps the tusk grow straight and strong, while providing stability against bending and twisting.
  • Function: Their tusks may help males establish social hierarchy during contests.
    • They may also be used for play, detecting the level of salt in the waters through which narwhals swim, and investigating, manipulating, and influencing the behaviour of prey.
• Threats:
  • Oil and gas development
  • Climate change
• IUCN Status: Least Concern