Phylum Platyhelminthes Flatworms Flukes Tapeworms Phylum Platyhelminthes

Phylum Platyhelminthes

Phylum Platyhelminthes

Phylum Platyhelminthes

Phylum Platyhelminthes

Phylum Platyhelminthes Flatworm Body Plans Exhibit bilateral symmetry, acoelomate and……… Phylum Platyhelminthes

Phylum Platyhelminthes Regeneration Many species posses remarkable powers of regeneration and repair wounds Phylum Platyhelminthes

Phylum Platyhelminthes Planarians are capable of asexual reproduction via fission Phylum Platyhelminthes

Phylum Platyhelminthes Reproduction Almost all are simultaneous hermaphrodites Parasitic species (flukes and tapeworms) have complex lifecycles, Phylum Platyhelminthes

Phylum Platyhelminthes Nervous System Free-living species usually have a well-developed sensory system Parasites generally have less elaborate systems. WHY? Phylum Platyhelminthes

Phylum Platyhelminthes Flatworms Some species also have a protrusible pharynx that captures food and transfers it into the mouth Can be carnivores or scavenge on dead animals and detritus Phylum Platyhelminthes

Phylum Platyhelminthes Tapeworms Phylum Platyhelminthes

Phylum Platyhelminthes Beef tapeworm Phylum Platyhelminthes

Problems of a parasitic existence Must reproduce within the definitive host Must get fertilized eggs out of the host Finding a new and appropriate host Obtain entrance into the host Locate the appropriate environment within the host Maintain position within the host Withstand an often anaerobic environment Avoid digestion or attack by the hosts immune system Avoid killing the host, at least until reproduction is completed Phylum Platyhelminthes