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Describe the Major Characteristics of a Roundworm

Roundworms, also known as nematodes, are invertebrates, as they lack a vertebral column. Roundworms live in soil and water, and some parasitic species are hosted by plants and animals. Parasitic species lay eggs on the ground and might access the host's body through the skin or the mouth. Some roundworms are microscopic, while others can measure up to 4 feet. Roundworms have unique characteristics that distinguish them from other worm species.

  1. Body Skeleton

    • Roundworms' bodies are covered with a thick cuticle, which is often shed to permit growth. Muscles along their length are located between the pseudocoel and cuticle. These muscles press on the pseudocoel and cuticle, resulting in a hydrostatic skeleton. The pseudocoel plays a vital role, since it can resist or permit rigidity, depending on the muscular pressure excreted. Rigidity eases the motion of the roundworm by lessening the contraction of muscles.

    Digestive System

    • Roundworms have a defined digestive system, running from the mouth to anus with a muscular esophagus, consisting of protruding sensory organs and sharp structures. Food is crushed in the mouth, diluted by water, absorbed in the body and finally excreted through an opening in the posterior.

    Reproductive System

    • Male roundworms are usually a bit smaller than the females, whose tails are bent. Nematodes normally undergo six developmental phases, ranging from the egg stage through four larvae phases and finally the adult phase. Based on their species, males can have either two or one testes and various other sex organs. Female nematodes produce the eggs, which are laid after fertilization. After the embryos within the eggs mature, they hatch to the first larval stage. These first larvae molt four times to develop to a reproductive adult. Nematodes grow during this molting, as a result of shedding off the skin. Parasitic roundworms are infectious during the third larvae phase and easily shift from one host to another. Nematodes have low cell multiplications but grow essentially through enlargement of cells.

    Nervous System

    • The nematode's nervous system is made up of the anterior nervous cells found in the pharynx. These cells form the central nervous system of the heart and body nerve cords, located along the length of the roundworm.

    Nematode Nutrition

    • Parasitic roundworms such as filarial worms, pinworms and hookworms normally get nourishment by ingesting and sucking blood and feeding on the tissues and intestinal contents and other body fluids of the host. Nematodes living in the soil feed on bacteria, fungi and other organic matters. Roundworm feeding habits have detrimental effects on the host and can lead to vomiting, nausea, abdominal pain and weight and appetite loss in humans.

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