The Phylum Platyhelminthes
A Brief Overview
The flatworms, known as Platyhelminthes are a phylum of relatively simple bilaterian, unsegmented, soft-bodied invertebrate animals. Unlike other bilaterians (have a front and back end as well as a upside and down side), they have no body cavity, and no specialized circulatory and respiratory organs, which restricts them to having flattened shapes that allow oxygen and nutrients to pass through their bodies by diffusion. The digestive cavity has only one opening for both the ingestion (intake of nutrients) and egestion (removal of undigested wastes); as a result, the food cannot be processed continuously. Platyhelminthes are divided into Turbellaria, which are mostly nonparasitic animals such as planarians (organisms that usually reproduce through fragmentation), and three entirely parasitic groups: Cestoda, Trematoda and Monogenea.
The flatworms, known as Platyhelminthes are a phylum of relatively simple bilaterian, unsegmented, soft-bodied invertebrate animals. Unlike other bilaterians (have a front and back end as well as a upside and down side), they have no body cavity, and no specialized circulatory and respiratory organs, which restricts them to having flattened shapes that allow oxygen and nutrients to pass through their bodies by diffusion. The digestive cavity has only one opening for both the ingestion (intake of nutrients) and egestion (removal of undigested wastes); as a result, the food cannot be processed continuously. Platyhelminthes are divided into Turbellaria, which are mostly nonparasitic animals such as planarians (organisms that usually reproduce through fragmentation), and three entirely parasitic groups: Cestoda, Trematoda and Monogenea.
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Pseudobiceros bedfordi
Pseudobiceros bedfordi, (common names Persian carpet flatwormand Bedford's flatworm) is a species of flatworm in the family Pseudocerotidae.This species has two penises, which it uses to fence, in an attempt to inject sperm into its opponent in order to fertilize it, while avoiding being fertilized itself.The lack of circulatory and respiratory organs limits platyhelminthes to sizes and shapes that enable oxygen to reach and carbon dioxide to leave all parts of their bodies by simple diffusion. Hence, many are microscopic and the large species have flat ribbon-like or leaf-like shapes. The guts of large species have many branches, so nutrients can diffuse to all parts of the body.
Pseudobiceros bedfordi, (common names Persian carpet flatwormand Bedford's flatworm) is a species of flatworm in the family Pseudocerotidae.This species has two penises, which it uses to fence, in an attempt to inject sperm into its opponent in order to fertilize it, while avoiding being fertilized itself.The lack of circulatory and respiratory organs limits platyhelminthes to sizes and shapes that enable oxygen to reach and carbon dioxide to leave all parts of their bodies by simple diffusion. Hence, many are microscopic and the large species have flat ribbon-like or leaf-like shapes. The guts of large species have many branches, so nutrients can diffuse to all parts of the body.
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Pseudoceros dimidiatus
Pseudoceros dimidiatus, or the divided flatworm, is a species of flatworm in the genus Pseudoceros. The divided flatworm varies in color between individuals, however all individuals of Pseudoceros dimidiatus have a black body with an orange margin. These bright colors serve as a warning for predators to not eat this species. The divided flatworm also grows to be up to 3 inches long (8 cm). They are also cold blooded.The divided flatworm lives in coral reefs in the tropical waters of the Indian Ocean and the Western Pacific Ocean.The lack of circulatory and respiratory organs limits platyhelminthes to sizes and shapes that enable oxygen to reach and carbon dioxide to leave all parts of their bodies by simple diffusion. Hence, many are microscopic and the large species have flat ribbon-like or leaf-like shapes. The guts of large species have many branches, so nutrients can diffuse to all parts of the body.
Pseudoceros dimidiatus, or the divided flatworm, is a species of flatworm in the genus Pseudoceros. The divided flatworm varies in color between individuals, however all individuals of Pseudoceros dimidiatus have a black body with an orange margin. These bright colors serve as a warning for predators to not eat this species. The divided flatworm also grows to be up to 3 inches long (8 cm). They are also cold blooded.The divided flatworm lives in coral reefs in the tropical waters of the Indian Ocean and the Western Pacific Ocean.The lack of circulatory and respiratory organs limits platyhelminthes to sizes and shapes that enable oxygen to reach and carbon dioxide to leave all parts of their bodies by simple diffusion. Hence, many are microscopic and the large species have flat ribbon-like or leaf-like shapes. The guts of large species have many branches, so nutrients can diffuse to all parts of the body.
![Picture](/uploads/2/0/0/6/20069161/4207867.jpg)
Pseudobiceros hancockanus
Pseudobiceros hancockanus is a species of hermaphroditic marine flatworm in the family Pseudocerotidae. According to the Baensch Marine Atlas, "P. hancockanus is intense blue to black with white and orange peripheral bands and a purple fringe. The two short cephalic antennaie are easily overlooked because they are the same color as the body. Inferiorly, this species is purple with a medial line." P. hancockanus is very similar in appearance to P. uniarborensis, although the margin of P. uniarborensis is translucent gray with a white line only on the outside, while the margin of P. hancockanus is pure bright white. Pseudobiceros hancockanus lives in warm seas, sometimes on coral reefs, other times among coral fragments or stones. It has been observed near such places as Indonesia, Fiji, and Kenya. Pseudobiceros hancockanus can travel long distances, swimming by undulating the edges of its body.The lack of circulatory and respiratory organs limits platyhelminthes to sizes and shapes that enable oxygen to reach and carbon dioxide to leave all parts of their bodies by simple diffusion. Hence, many are microscopic and the large species have flat ribbon-like or leaf-like shapes. The guts of large species have many branches, so nutrients can diffuse to all parts of the body.
Pseudobiceros hancockanus is a species of hermaphroditic marine flatworm in the family Pseudocerotidae. According to the Baensch Marine Atlas, "P. hancockanus is intense blue to black with white and orange peripheral bands and a purple fringe. The two short cephalic antennaie are easily overlooked because they are the same color as the body. Inferiorly, this species is purple with a medial line." P. hancockanus is very similar in appearance to P. uniarborensis, although the margin of P. uniarborensis is translucent gray with a white line only on the outside, while the margin of P. hancockanus is pure bright white. Pseudobiceros hancockanus lives in warm seas, sometimes on coral reefs, other times among coral fragments or stones. It has been observed near such places as Indonesia, Fiji, and Kenya. Pseudobiceros hancockanus can travel long distances, swimming by undulating the edges of its body.The lack of circulatory and respiratory organs limits platyhelminthes to sizes and shapes that enable oxygen to reach and carbon dioxide to leave all parts of their bodies by simple diffusion. Hence, many are microscopic and the large species have flat ribbon-like or leaf-like shapes. The guts of large species have many branches, so nutrients can diffuse to all parts of the body.