Nematodes move through the contraction of their longitudinal muscles. There is high internal body pressure when these muscles contract, which causes the body of the nematode to flex instead of flatten. The thrashing caused by this back and forth movement propels a nematode forward.
Nematodes have no cilia or flagellae to help with their movement, according to the University of Michigan Museum of Zoology.
During the fertilization process, a male nematode uses copulative spines to open the female's reproductive tracts to inject sperm into them. Nematode sperm also doesn't have any flagellae present and therefore, they move using pseudopodia in the same way as amoebas. Nematodes, or round worms as they are commonly called, are simple worm-like organisms that are highly abundant in the environment. There are over 12,000 described distinct species of nematodes with some types occurring widely in many different environments, while others are specialized to one particular habitat.
The nematodes play a critical role as decomposers and predators of many microorganisms in the environmental ecosystem. However, nematodes can also infect humans both directly or indirectly through contact with domestic animals. Common species that infect humans include pinworms, hookworms and trichina, which is the parasite that causes trichinosis.Learn More
There are two sets of muscles that help annelids move. One expands, and the other contracts the body. Annelids alternate the use of these muscles to achieve locomotion.Full Answer >
Sharks move through the water with the help of their tail fins. The body of a shark is light as it is made of cartilage and not bones. It has a perfectly streamlined body. Its dorsal fins help it steer through the water.Full Answer >
Mammals move by using contractile muscles that pull against attachment points in their rigid internal skeletons, causing the bones to change orientation relative to each other around specific joints. This muscle contraction directly affects the movement, as the muscle pulls in a linear fashion in the direction the mammal wants the bones to move. This method of motion is shared by all vertebrates with internal skeletons.Full Answer >
Invertebrates use their muscles to move. Most invertebrates have the ability to move, but some do not. Once some invertebrates, such as sea sponges, settle in one place, they will not move again to another location, according to Biology 4 Kids. Some invertebrates may move in search of food, but others are stationary and can create their own food.Full Answer >