In geophysics the refraction or reflection of seismic waves is used for research into the structure of the Earth's interior, and man-made vibrations are often generated to investigate shallow, subsurface structures.
Flatworms are considered acoelomate, since they have no body cavity, and roundworms are pseudocoelomate because they have a body cavity, but it is not derived from the splittiâ¦ng of the mesoderm tissue. Also, flatworms only have one opening in their digestive system unlike roundworms with two.
Parasitic Flatworms. While there are several parasitic flatworms, tapeworms and flukes are the two most commonly studied types. These flatworms are capable of causing diseases in different host organisms, such as fish, dogs, domesticated animals, and humans.Advertisement. Flatworms are invertebrates, characterized by their minute-size or flattened, unsegmented, bilateral, soft body.hese flatworms are capable of causing diseases in different host organisms, such as fish, dogs, domesticated animals, and humans. Advertisement. Flatworms are invertebrates, characterized by their minute-size or flattened, unsegmented, bilateral, soft body.