Platyhelminthes
phylum that has 3 germ layers and is cephalized
Platyhelminthes is a phylum of invertebrate animals commonly known as flatworms.
Characteristics:
– Flat body shape: They have a flattened body with no body cavity or segmentation.
– Cephalization: They have a distinct head with sensory structures such as eyespots, and a nervous system.
– Acoelomate: They lack a true coelom, which is a body cavity lined with mesodermal tissue.
– Incomplete gut: They only have one opening for both ingestion and waste elimination.
– Hermaphrodites: Flatworms can have both male and female reproductive organs in one individual.
Classes:
1. Turbellaria: This class contains free-living marine and freshwater flatworms that feed on small organisms and detritus.
2. Cestoda: This class are parasitic worms that live in the intestines of vertebrates, such as tapeworms.
3. Trematoda: This class are parasitic flatworms that live in the tissues of various animals, such as liver flukes and blood flukes.
Importance:
Flatworms are important for their ecological roles. They play a key role in nutrient cycling in aquatic ecosystems, and some species like planarians are used as model organisms in research due to their regenerative abilities. However, some flatworms can be serious parasites of humans and livestock and cause significant health and economic problems.
More Answers:
Unveiling the Fascinating Characteristics of Planaria: Their Anatomy, Regenerative Abilities, Feeding, Habitat and Reproduction.The Fascinating World of Dugesia Planarians: Regenerative Abilities and their Contributions to Biology Research
Discovering Turbellarians: Small, Free-Living Flatworms with Unique Characteristics and Habits.