PARASITES:) - WORMS
Picture of parasite !
Where they live ?
How they feed !
Parasitic flatworms feed on blood, tissue fluids, or pieces of cells inside the bodies of their hosts. Some of these animals have a pharynx that pumps food into a pair of dead-end intestinal sacs where the food is digested, but in many parasitic flatworms the digestive tract is simpler than in free-living forms. For example, tapeworms, a common type of parasitic flatworm, has no digestive tract at all...Â instead, they live inside the intestines of their hosts and feed by latching onto the intestinal wall with hooks and/or suckers and absorbing the food that passes by- food that has already been broken down by the host's digestive enzymes.
Flatworms lack any kind of specialized circulatory or respiratory system. Because they are so flat, they can depend on diffusion to transport oxygen and nutrients to their tissues. And they can get rid of carbon dioxide and most other metabolic wastes by allowing them to diffuse out through their body walls.Parasitic flatworms also often do not have much of a nervous system. As you can imagine, there is not much need for a nervous system in an organism that mainly hangs onto an intestinal wall and absorbs food! In fact, in tapeworms the nervous system has completely disappeared as the worms have adapted to their parasitic lifestyle. In contrast with free-living flatworms, parasitic flatworms do not reproduce asexually, but instead often have complicated life cycles.
How they reproduce!
Generally all flatworms are hermaphroditic, meaning an individual flatworm has both male and female reproductive components. They engage in sexual and asexual reproduction, with the dominant mode of reproduction varying among species.
Asexually, flatworms procreate via fragmentation and budding. Fragmentation, also called cloning, occurs when a flatworm splits off a part of its body, allowing the separated portion to regenerate into a new worm. With budding, a flatworm grows an extension from its body. This extension, or bud, becomes a new worm and separates from the original flatworm.
There are also multiple methods of flatworm sexual reproduction. Because a flatworm is hermaphroditic, it can produce eggs within its body and also fertilize them with sperm, also generated in its body. Another method of reproduction involves physical contact between two flatworms, where the sperm of one flatworm is absorbed into the skin of another. With some species, this occurs through penis fencing, where flatworms use their penis to compete in trying to pierce the skin of a potential mother.
Ultimately, fertilized eggs are encased in a cocoon within a flatworm's body. The cocoon is released into environments such as amid water weeds. The cocoon nourishes the eggs, which develop and later hatch.
What are the host ?
In biology, a host is an organism that harbors a parasite, or a mutual or commensal symbiont, typically providing nourishment and shelter. In botany, a host plant is one that supplies food resources and substrate for certain insects or other Fauna. Examples of such interactions include a cell being host to a virus, a bean plant hosting helpful nitrogen-fixing, bacteria, and animals as hosts to parasitic worms, e.g. Nematodes.