Nematode (Roundworm)
Scientific Name: Nematoda (Phylum)
Order & Family: Phylum Nematoda (no specific order/family can be determined from the images)
Size: Most nematodes are microscopic, ranging from 0.02 mm to 3 mm in length, making them difficult to see with the naked eye. Some parasitic species can be much larger, reaching several centimeters or even meters (e.g., whale placental nematode).
Natural Habitat
Nematodes are ubiquitous and can be found in virtually all environments, including marine, freshwater, and terrestrial habitats. They are abundant in soil, sediment, hot springs, polar ice, and elevated areas such as mountains. They also live as parasites within plants, animals, and humans.
Diet & Feeding
Diet varies greatly depending on the species. Free-living nematodes can be bacterivores (feeding on bacteria), fungivores (feeding on fungi), predators (feeding on other nematodes or small invertebrates), or omnivores. Plant-parasitic nematodes feed on plant roots. Animal-parasitic nematodes feed on the tissues, blood, or intestinal contents of their hosts.
Behavior Patterns
Nematodes move in a characteristic undulating or thrashing motion. Many are free-living and are important decomposers or predators of other microorganisms. Parasitic nematodes have complex life cycles, often involving multiple hosts. They can be found in soil, water, or within the tissues of plants and animals.
Risks & Benefits
Risks: Many nematode species are parasites of humans, animals, and plants, causing significant diseases and economic losses in agriculture (e.g., hookworms, Ascaris, root-knot nematodes). Benefits: Free-living nematodes play vital roles in nutrient cycling and decomposition in ecosystems. Some species are used as biological control agents against insect pests (entomopathogenic nematodes) and plant pests, offering an environmentally friendly alternative to chemical pesticides. They are also important model organisms in biological research (e.g., Caenorhabditis elegans).
Identified on: 8/27/2025