Which way does blood flow in an earthworm?
As fresh air is taken in through the skin, oxygen is drawn into the worm’s circulatory system, and the worm’s hearts pump the oxygenated blood to the head area. The movements of the worm’s body make the blood flow back to the back end of the body, and the hearts pump the blood forward again.
What type of gut do flatworms have?
Most flatworms have an incomplete digestive system with an opening, the “mouth,” that is also used to expel digestive system wastes. Some species also have an anal opening. The gut may be a simple sac or highly branched.
Where can flatworms be found?
Most freshwater flatworms are free-living and can be found in ponds, lakes, streams, ditches, and temporary puddles.
- They live under rocks, plants, and debris to avoid direct sunlight.
- They can be found on hard and soft substrates, but are more common on the hard surfaces.
Do flatworms have a body cavity?
Flatworms have no body cavity other than the gut (and the smallest free-living forms may even lack that!) and lack an anus; the same pharyngeal opening both takes in food and expels waste.
How do flatworms excrete?
In flatworms, excretion is accomplished by the epithelial lining of the gut, by the body wall, by exocytosis of vesicles, and by protonephridia. The Catenulida are the only flatworms that have an unpaired protonephridial system and a unique terminal cell type.
Which cells do the flatworms have for excretion?
(2) Flatworms have an excretory system that consists of two tubules. The cells in the tubules are called flame cells; they have a cluster of cilia that propel waste matter down the tubules and out of the body.
What is flatworm excretory system?
Flatworms have an excretory system with a network of tubules throughout the body that open to the environment and nearby flame cells, whose cilia beat to direct waste fluids concentrated in the tubules out of the body. The system is responsible for regulation of dissolved salts and excretion of nitrogenous wastes.
What is a flatworms locomotion?
Small flatworms (Platyhelminthes) and some of the smaller molluscan species move along the bottom by ciliary activity. On their ventral (bottom) surface, a dense coat of cilia extends from head to tail. The direction of the ciliary beat is tailward, causing the animal to glide slowly forward.