#Platyhelminthes
Platyhelminthes are commonly known as flatworms, these can range from parasitic to free living marine species. The size of platyhelminthes can range from 1mm to 25 m. There are now only 34,000 known species. These organisms have parenchyma tissue. Parenchyma is a mesodermally derived tissue that are used to fill spaces in between the gut, organs. and outer body wall. Parenchyma also functions as skeletal support, nutrient storage, motility, reserves of regenerative cells, transporting materials, structural interactions with other tissues, modifiable tissue for morphogenesis, storing oxygen, and various other functions.