Web28.3 Superphylum Lophotrochozoa: Flatworms, Rotifers, and Nemerteans. This section describes three phyla of relatively simple invertebrates: one acoelomate, one pseudocoelomate, and one eucoelomate. Flatworms are acoelomate, triploblastic animals. They lack circulatory and respiratory systems, and have a rudimentary excretory system. WebTypes. Flatworms can either live independently or as a parasite in a host body. The main types of flatworms that exist are those that live on the land which belong to the phylum platyhelminthes class and those that dwell …

Immortal Worms ( Real World ) Biology CK-12 Foundation

WebAug 26, 2010 · Figure 15.16 Phylum Platyhelminthes is divided into four classes: (a) Bedford’s Flatworm (Pseudobiceros bedfordi) and the (b) planarian belong to class Turbellaria; (c) the Trematoda class includes about 20,000 species, most of which are parasitic; (d) class Cestoda includes tapeworms such as this Taenia saginata; and the … WebJan 11, 2024 · Flatworms range in length from about 1 millimeter (0.04 inches) to more than 20 meters (66 feet). They have a flat body because they do not have a coelom or even a pseudocoelom. They also lack a respiratory system. Instead, their cells exchange gases by diffusion directly with the environment. They have an incomplete digestive system. rick forgay

Flatworms - Advanced ( Read ) Biology CK-12 Foundation

WebDiversity of Flatworms. The flatworms have been traditionally divided into four classes: Turbellaria, Monogenea, Trematoda, and Cestoda (Figure 28.15).However, the … WebDec 11, 2015 · Animals with bilateral symmetry, 3 germ layers, organ systems, and distinct heads. Flatworms - Advanced. WebIn Summary: Phylum Platyhelminthes. Flatworms are acoelomate, triploblastic animals. They lack circulatory and respiratory systems, and have a rudimentary excretory system. This digestive system is … rick forman bio