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.
All flatworms have a soft body and a triangle-shaped head. They also have eye-spots on top of their heads which can see light. Flatworms are not closely related to most other worms, such as earthworms. Bodies are flat instead of round, and they do not have segments.Flatworms spend most of their time on the bottom, especially since they can't swim.rocotyla fluviatilis can also migrate by streams to other bodies of water. Flatworms are less active when the water is very warm or when they are fully fed. Flatworms, also called planarians, are found just about everywhere there is water.