Phylum: Platyhelminthes
Structures: The flatworms are just like their name flat. These are the simplest animals that are bilaterally symmetrical and have three fundamental cell layers. They have no body cavity other than the gut and lack an anus. The lack of a cavity also constrains flatworms to be flat.
Body Covering/Support: The space between the skin and gut is filled with a connective tissue and is reinforced by collagen fibres that act like a skeleton. The mesenchyme contains all the internal organs and consists of two main cells, fixed cells and stem cells.
Body Covering/Support: The space between the skin and gut is filled with a connective tissue and is reinforced by collagen fibres that act like a skeleton. The mesenchyme contains all the internal organs and consists of two main cells, fixed cells and stem cells.
Response: Flatworms use camouflage to hide in plain site or to look like another animal entirely when they are being attacked or hunted. Some can also match the texture and color of the food they want to eat. Some can use colour mimicking to go invisible. While others defy these laws and flash bright colors and patterns to scare predators and other worms away. Many marine flatworms can also secrete toxins on the predator, to let go, before they are killed.
|
Nutrition/Circulation of Nutrients: The mesenchyme contains all the internal organs and allows the passage of oxygen, nutrients and waste products. Their gut is lined with a single layer of endodermal cells that absorb and digest food. They have no anus so they eat and dispose materials through their mouth.
Respiration: They have no respiration systems and obtain their oxygen and eliminate carbon dioxide by simple diffusion. Repertory through the whole body makes them vulnerable to fluid loss which limits them to environments where dehydration is unlikely. |
|
Reproduction: the flatworms have both male and female sexual organs meaning they are hermaphrodites. They are able to produce asexualy and sexually but, sexual reproduction is preferred. They have three methods of reproduction they can fertilize their own eggs, they can regenerate a complete organism from a piece of themselves and they can reproduce sexually with a partner. Reproducing sexually is quicker and safer. To reproduce worms fight until one is finally stung with the double daggers(their penis) and is injected with the sperm. The loser of the battle than has to carry the burden of motherhood.
|
![Picture](/uploads/9/6/4/5/96451706/published/417111488.jpg?1485040915)
Classes:
Cestoda: They are long, flat and ribbon- like organisms known as tapeworms.These tapeworms can grow up to 20 meters long. All of them are parasitic and live in bodies of other species of animals. Humans can be subjected to their infection is they eat under cooked meat, fish and live in poor hygiene.
Cestoda: They are long, flat and ribbon- like organisms known as tapeworms.These tapeworms can grow up to 20 meters long. All of them are parasitic and live in bodies of other species of animals. Humans can be subjected to their infection is they eat under cooked meat, fish and live in poor hygiene.
![Picture](/uploads/9/6/4/5/96451706/published/669264951.jpg?1485040878)
Trematoda: These worms are known as flukes and are also parasitic. They usually host in a molluscs or a vertebrate.
![Picture](/uploads/9/6/4/5/96451706/published/627073658.jpg?1485040833)
Turbellaria: This class is the most primitive. These are the flatworms. Their shapes are ribbon- like or leaf-like. They live in water or in moist terrestrial environments.