Phylum Nematoda

• What is the common name for Nematoda?

  Roundworms
• What are the defining characteristics of Nematoda?

  Paired lateral sensory organs called amphids
• How many species of Nematoda have been described?

  About 16,000 species
• Where do most Nematodes inhabit?

  Terrestrial and aquatic areas
• What is the most common lifestyle of Nematodes?

  Most are parasitic
• What is the most abundant multicellular organism?

  Nematodes
• How do some Nematodes cause disease in humans?

  By burrowing into muscle tissue forming cysts
• What disease does Trichinella spiralis cause in humans?

  Trichinosis

  
• What is cryptobiosis in Nematodes?

  Altered metabolism in response to environmental changes
• What is the largest known Nematode?

  Placentonema gigantissima
• What is the body architecture of Nematodes?

  Unsegmented, acoelomate or pseudocoelomate

  
• What type of symmetry do Nematodes exhibit?

  Bilateral symmetry
• How do Nematodes absorb oxygen?

  Through their skin via diffusion
• What is the hydrostatic skeletal system in Nematodes?

  A fluid-filled cavity surrounded by muscles
• What characterizes the digestive system of Nematodes?

  It is a complete digestive system
• What are the three parts of the Nematode digestive system?

  Stomodeum, intestine, proctodeum
• What does the stomodeum consist of?

  Mouth, lips, buccal cavity, pharynx
• What is the function of the intestine in Nematodes?

  Digests, absorbs water and nutrients
• What is the role of the proctodeum?

  Serves as the anus for waste excretion
• What is the reproductive strategy of most Nematodes?

  Mostly dioecious with amoeboid sperm
• How do male Nematodes differ from females?

  Males are smaller and have a bent tail
• What is the function of spicules in male Nematodes?

  Inserted into female's genital pore for copulation
• What is the cuticle in Nematodes?

  Flexible outer covering acting as an exoskeleton
• What are the functions of the cuticle in Nematodes?

  Protection, sensory detection, hydrostatic skeleton
• How are Nematodes classified taxonomically?

  Divided into three major classes
• What are the three major classes of Nematodes?

  Enoplia, Dorylaimia, Chromadoria
• What characterizes Class Enoplia?

  Free-living and predatory nematodes
• What is the significance of Family Tricodoridae?

  Important parasite of plant roots
• What does Class Dorylaimia include?

  Many free-living and parasitic species
• What is Order Dorylaimida known for?

  Includes ectoparasitic species on plants
• What is unique about Order Mermethida?

  Larval stages parasitize invertebrates
• What does Order Rhabditida contain?

  Members of the former class Secernentea
• What is the ecological role of free-living nematodes?

  Decomposition and recycling in ecosystems
• How do free-living nematodes contribute to aquaculture?

  Potential food sources for aquaculture
• What do free-living nematodes consume?

  Living tissues, small animals, dead organisms
• Why are marine nematodes sensitive to pollution?


  They play a large role in decomposition
• What is the life cycle of nematodes associated with fig wasps?

  Nematodes penetrate and consume female wasps
• What disease is caused by hookworms?

  Necator americanus infection
• What is the cause of elephantiasis?

  Parasitic infection of filarial nematodes
• What is trichinosis caused by?

  Eating undercooked meat infected with T. spiralis