Platyhelminthes by Briana Nelson

1 of 5

Slide Notes

Platyhelminthes

Published on Dec 08, 2015

No Description

PRESENTATION OUTLINE

PLATYHELMINTHES

BY:BRIANA

Photo by Marc Perkins - OCC Biology Department

Platyhelminthes- is the "technical" name for a flat worm including the planaria! D:
Platy: Greek for "flat"
Helminthes: worm

Photo by Philippe Guillaume

What are their bodies like?
They are acoelomates (having no body cavity) triploblastic (having three tissue layers) most are somewhat symmetrical, and they have some form of digestive and reproductive, and nervous system. But no respiratory system.

To break it down even more they can separate into three different classes.
Turbellaria: includes all free-living members, as well as a few parasites. It includes many marine forms whose bright colors tell their predators of their toxicity.
Trematoda: or else called flukes are not segmented flat-worms. Thy reproduce asexually, they need what is called a host
Cestoda: are called tapeworms, these are segmented, they are ribbon like parasites. They have NO digestive tract, and each little segment is a reproductive organ. If infected most of the time tapeworm infections aren't as medically serious as Trematode infections.

Photo by BioDivLibrary

Fossils?..
It's really hard to figure out exactly how long flatworms have been on earth because of their soft squishy bodies they don't preserve well. Scientist believe they first evolved about 550 million years ago.
There are around 25,000 known species. Schistosomiasis is the one to watch out for, it has caused serious suffering and death, over 200 million people are infected with this in the tropical countries.

Briana Nelson

MORE DECKS BY THIS AUTHOR

What Is Haiku Deck?

20 views

Nematoda

364 views

Phylum Cnidaria

163 views

Amphibians

79 views

Mollusca

57 views