Nematoda And Platyhelminthes

Nematoda and Platyhelminthes

Within this lab we discussed and viewed platyhelminthes which is the scientific term for flatworm. The flat worms are phylum simple soft, bodied invertebrate animals. There are about twenty five thousand known species; they are the largest phylum of acoelomates. Flatworms are found in marine, freshwater, and even damp terrestrial environments. Most flatworms are free living, but many are parasitic. There are four classes: Trematoda (flukes) Cestoda (tapeworms), Monoglenea, and Turbellaria.

The materials that were used within this lab were various slides of Nematoda and Platyhelminthes that were placed underneath the microscope to exam. The results in this lab were that the Nematoda differ somewhat from the Platyhelminthes such as in their characteristics of sexually reproduction and the body shape….etc.

The Flatworm has a soft body ribbon shaped flattened dorso-ventrally (from the top to bottom) and bilaterally symmetric. Flatworms are the simplest tripoblastic animals with organs. This means the organ system forms out of three germ layers: an outer ectoderm and an inner endoderm with a mesoderm between them. Turberllarians generally have a ciliated epidermis. There is also no body cavity except the gut; hence flatworms are classified as acoelmates. The interior flatworms exhibit an undulating form of locomotion. Depending on species and age, individuals can range in sixe from almost microscopic to over twenty meters long. The longest ever recorded flatworm was a tapeworm over ninety feet long.