The Nematoda(round worms)

Major Characteristics

• Animal Characteristics

• Cylinderical and bilateral

• Triploblastic• Pseudocoelomate• Complete digestive

system• Tough cuticle

Body Plan

• Nematodes are composed of an ectoderm, mesoderm, endoderm making them triploblastic

• They contain a false cavity because it is located between the endoderm and mesoderm

Movement

• Round worms contain longitudinal muscle that run parallel to the anterior/posterior axis

• Contraction and relaxation of muscles on opposites sides of the animal create the characteristic whip like serpentine movement

Feeding

• The nematode have a complete digestive system with a mouth and anus

• One way travel of nutrient allows for divergence and specialization of digestive function along the digestive tract

Parasites

• Nematode parasites reproduce at a high rate, an enzyme resistant cuticle and eggs, with encysted larvae

• They include intestinal worms, the pork worm (trichinosis), and filarial worms (elephantiasis)