Ascaris lumbricoides (Large Roundworm) – Adult

  • Disease: Ascariasis
  • Habitat in human: Small intestine
  • Diagnosis of infection: Microscopic examination of faeces to detect eggs
Morphological Features
  • Comparatively large and plump largest nematode parasite of human
  • Colour: Creamy white or pink
  • Cuticle has fine circular striations
  • Mouth is surrounded by three lips – one dorsal and two ventrolateral
  • Oesophagus is club-shaped without posterior bulb
  • Size:15-30 cm long
  • Posterior end is curved
  • Two copulatory spicules of unequal size
  • 20-35 cm long – Larger than the males
  • Posterior end is straight
  • Two ovaries
  • Vulva is situated about 1/3rd of body length from anterior end

Magnification X0.5