Ascaris lumbricoides - Adult female

France, Pihet Marc

Ascaris lumbricoides is the largest nematode inhabiting the human digestive tract. The female measure 20 to 25 cm in length, 3 to 6 mm in width and has a tapered posterior end, while the male is usually smaller (15 to 17 cm long and 2 to 4 mm wide) and has a curved posterior end with spikes. Life worms appear with a pinkish tint and become pearly white after death.