nematoda

• from Greek, “nematos” which means “thread.”
• Found in freshwater, soil, and marine habitats
• Triploblastic, bilateral, vermiform (resembling a worm in shape; long and slender), unsegmented, pseudocoelomate
• Pseudocoelom is fluid filled, contains visceral organs and forms hydrostatic skeleton.
• Complete digestive system: mouth, buccal cavity, muscular pharynx, long intestine (digestion and absorption), rectum and anus
• Body wall has only longitudinal muscles. Longitudinal muscle contraction results in undulatory waves moving from anterior to posterior
• Osmoregulation and excretion of nitrogenous wastes. Glandular system in aquatic species uses ventral glands called renettes.
• Renettes are glands that absorb metabolic waste products from pseudocoelom and empties them outside through an excretory pore.
• Most are dioecious and dimorphic (males are smaller)