Platyhelminthes, also known as flatworms, are a phylum of invertebrate animals that have a flat, ribbon-like body shape. They are found in marine, freshwater, and terrestrial environments, and are known for their ability to regenerate body parts.
Characteristics of Platyhelminthes
Platyhelminthes are characterized by their flattened, ribbon-like body shape. They have a soft, unsegmented body without any internal or external skeleton. They have a simple nervous system that includes a pair of nerve cords and a nerve net, and some species have eyespots that allow them to detect light and dark. Platyhelminthes are also known for their unique excretory system, which includes specialized flame cells that remove waste and excess water from the body.
Examples of Platyhelminthes include planarians, tapeworms, and flukes. Planarians are free-living flatworms found in freshwater environments, while tapeworms and flukes are parasitic flatworms that infect animals such as humans and livestock.
Examples of Platyhelminthes
Platyhelminthes have bilateral symmetry, meaning that their left and right sides are mirror images of each other.
Platyhelminthes nervous system
They have a simple nervous system, with a primitive brain and nerve cords that run along their body.
They also lack a respiratory system and circulatory system, and instead rely on diffusion to exchange gases and nutrients with their environment.
Platyhelminthes digestive system
The digestive system of Platyhelminthes is incomplete, with a single opening for both ingestion of food and excretion of waste. Some species have a mouth, while others absorb food through their body surface.
Flame cells in Platyhelminthes
Platyhelminthes have flame cells what is their significance?
Platyhelminthes are known for their flame cells, which are specialized cells that help regulate water balance and excretion. Flame cells are found in the excretory system of flatworms, and use cilia to move excess water and waste out of the body. Their significance is to help maintain the osmotic balance in the body of flatworms.
Platyhelminthes Skeleton Type
Platyhelminthes do not have a skeleton, either internal or external. Their bodies are soft and flexible, allowing them to move easily through their environments. Some species, such as the planarians, have a layer of muscle fibers that allows them to change their body shape and move in different directions.
Platyhelminthes Excretory System
Platyhelminthes have a unique excretory system that includes specialized cells called flame cells. Flame cells are located in the body cavity and have cilia on their surface that create a current, allowing them to remove waste and excess water from the body. The waste products are excreted through a series of tubules and ducts that lead to an excretory pore located on the underside of the body.
How do Platyhelminthes Reproduce
Platyhelminthes have a variety of reproductive strategies. Some species, such as planarians, can reproduce asexually by regenerating lost body parts or by dividing their body in half.
Others, such as tapeworms, reproduce sexually. Tapeworms have complex reproductive systems that include both male and female reproductive organs, and they release eggs that are then passed out of the body in the host’s feces.
Do Platyhelminthes Have Eyes
Some species of Platyhelminthes have eyespots that allow them to detect light and dark. Eyespots are simple structures that are sensitive to changes in light and are not capable of forming images. They are used by flatworms to detect the presence or absence of light and to move towards or away from light sources. However, not all Platyhelminthes have eyespots, and some species rely on other sensory structures to navigate their environments.