litteentyviä

Litteentyviä is a Finnish term that translates to "flatworms" in English. It refers to a phylum of invertebrates within the animal kingdom. These creatures are characterized by their flattened bodies, which can be either unsegmented or segmented, though segmentation is less common than in other invertebrate groups.

Flatworms exhibit bilateral symmetry, meaning their bodies can be divided into two mirror-image halves. They possess a rudimentary nervous system and a digestive system that is often incomplete, with a single opening serving as both mouth and anus. Many species are free-living, inhabiting aquatic environments such as oceans, freshwater, and even moist terrestrial habitats. Others are parasitic, living on or inside other organisms and deriving nutrients from their hosts.

The phylum Platyhelminthes, which encompasses flatworms, is diverse and includes well-known groups like planarians, flukes, and tapeworms. Planarians are often studied in biology for their remarkable regenerative abilities. Flukes and tapeworms, on the other hand, are significant as parasites of both humans and animals, causing various diseases. Despite their simple body structure, flatworms have successfully adapted to a wide range of ecological niches.