What is a "nematode"?

A nematode is a slender, unsegmented worm that belongs to the phylum Nematoda. They are among the most abundant animals on Earth and can be found in various habitats, including soil, freshwater, and marine environments. Nematodes have a distinct cylindrical body shape and are usually microscopic in size. They have a simple digestive system and are known for their remarkable ability to adapt and survive in diverse conditions. Some nematodes are free-living, while others are parasitic, infecting plants, animals, or humans. They play important roles in ecosystems, as they decompose organic matter and contribute to nutrient cycling. However, certain parasitic nematodes can cause diseases in humans, animals, and crops.