Parasitic flatworms can disrupt ecosystems. Some flatworms, planaria, can be used as models for toxicology Platyhelminthes from the Florida Museum of Natural History. The Marine Flatworm Galleries. Skip to main content. Videos Planaria illustrates bilateral symmetry.
A predatory flatworm hunts a snail, on land Flatworm swimming A flatworm lifting off from a coral reef and swimming A song, with video about flatworms. General information about flatworms Read about the advantages and disadvantages of being hermaphroditic A primer on marine flatworms for K Students From the Museum Victoria Victoria, Australia more about marine flatworms Read about a cave-dwelling freshwater flatworm A large group of flatworms are parasites that can infect humans causing diseases, read the article.
Images Download platyhelminthes. Download platyhelminthes. Download abFlatworm1. Download abflatworm2. Download flatworm1. Download flatworm2. Download flatworm3. Download flatworm4. Download flatworm5. Tapeworms and flukes have suckers and other structures for feeding on a host. Tapeworms also have a scolex , a ring of hooks on their head to attach themselves to the host see Figure below. Unlike other invertebrates, tapeworms lack a mouth and digestive system. Tapeworm Suckers and Hooks. The head of a tapeworm has several suckers.
Not all flatworms are parasites. Some are free-living carnivores. They eat other small invertebrates and decaying animals. Most of the free- living species live in aquatic habitats, but some live in moist soil. Would you believe that this gold-dotted creature is a flatworm? Flatworms Flatworms belong to the phylum Platyhelminthes. Platyhelminthes include flatworms, tapeworms, and flukes.
Structure and Function of Flatworms Flatworms range in length from about 1 millimeter 0. Flatworm Reproduction Flatworms reproduce sexually. Ecology of Flatworms Both flukes and tapeworms are parasites with vertebrate hosts, including human hosts. Summary Platyhelminthes are flatworms such as tapeworms and flukes. Flatworms have a mesoderm cell layer and simple organ systems. They also show cephalization and bilateral symmetry. The development of directional movement is correlated with cephalization.
In some flatworms, the process of cephalization has included the development in the head region of light-sensitive organs called ocelli. Other sense organs found in at least some members of this group not necessarily on the head include chemoreceptors, balance receptors statocysts , and receptors that sense water movement rheoreceptors.
Most flatworms can reproduce sexually or asexually. Most are monoecious. Most of these have developed ways of avoiding self-fertilization. Development may be direct eggs hatch into tiny worms that resemble the adults or indirect with a ciliated larval form. Flatworms include a large number of parasitic forms, some of which are extremely damaging to human populations.
Brusca, R. Sinauer Associates, Sunderland, MA. To cite this page: Myers, P.
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