The Platyhelminthes includes three classes:
the Turbellaria (free-living flatworms)
, the Trematoda (flukes), and the Cestoda (tapeworms).
What are the two major Platyhelminthes?
The Platyhelminthes consist of two lineages:
the Catenulida and the Rhabditophora
.
What are the four major classes of flatworms?
Some modern evidence suggests that at least some flatworm species may be secondarily simplified from more complex ancestors. The phylum consists of four classes:
Trematoda (flukes), Cestoda (tapeworms), Turbellaria (planarians), and Monogenea
.
What are the 3 classes of Platyhelminthes flatworms )?
The Phylum: Platyhelminthes includes the flatworms (Planaria, flukes & tapeworms) Three Classes treated here are
Turbellaria, Trematoda and Cestoda
.
What are the major or largest groups of Platyhelminthes?
Platyhelminthes are traditionally divided into four classes:
Turbellaria, Monogenea, Trematoda, and Cestoda
.
Who named Platyhelminthes?
PLATYHELMINTHES. Platyhelminthes (pla-te-hel-MIN-thes) is made of two Greek roots that mean “flat worms” [flat -plato (πλάτω); and worm -helmis (ελμισ)]. The reference is to the flattened nature of the animals in this phylum. The name was coined by
Gegenbaur (1859)
.
Where are Platyhelminthes 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.
Which class of Platyhelminthes are not parasitic?
Turbellaria
.
Turbellaria
are free-living flatworms. This means that they are able to find and digest their own food, and they do not depend on a host organism.
What are tapeworm segments called?
The adult tapeworm is made up of many small segments, called
proglottids
, each about the size of a grain of rice. Adult tapeworms may measure 4-28 inches in length. As the tapeworm matures inside the intestine, these segments (proglottids) break off and pass into the stool.
What diseases can flatworms cause in humans?
Paragonimiasis is caused by infection with a flatworm. That’s a parasitic worm also called a fluke or lung fluke because it commonly infects the lungs. Usually, infection comes after eating undercooked crab or crayfish that carry immature flukes.
What do humans and flatworms have in common?
Like humans, flatworms are
bilateral
: Their body plans are symmetric. … The team’s research proved that these flatworms represent the first creatures to split from a long-dead ancestor common to all bilateral animals.
What are flatworms characteristics?
Characteristics. Flatworms are
flattened and have bilateral symmetry
. They are triploblastic (have 3 embryonic tissue layers: ectoderm, mesoderm, and endoderm) and therefore have organ-level of organization. There is no body cavity, so they are acoelomate.
Can flatworms live in humans?
There are a variety of parasitic worms that can take
up residence in humans
. Among them are flatworms, thorny-headed worms, and roundworms. The risk of parasitic infection is higher in rural or developing regions. The risk is great in places where food and drinking water may be contaminated and sanitation is poor.
Are Monogenea ectoparasites?
While the
majority of Monogeneans are ectoparasites
, a few species are endoparasites and thus live inside the host. In various aquatic habitats, fish, and many other aquatic organisms (turtles, crustaceans, etc) act as the source of nutrition for a variety of ectoparasites that inhabit this environment.
