Animal Classification - Phylum Platyhelminthes Flashcards
The animals of the phylum Platyhelminthes are…………
Flatworms
Two groups of animals in this phylum
Class Cestoda (tapeworms) Class Trematoda (flukes)
They are endoparasite. What does that mean?
A parasitic organism that lives in the internal organs of the animal.
Common physical characteristics of flatworms
Symmetrical, distinct front anf rear end. Do not posses a internal body cavity. They have 3 cell layers, triploblastic. The are flat. They are hermaphrodites.
What does a hermaphrodite mean?
An organism that contains both male and female reproductive organs.
Class Cestoda, tapeworms. Give info on them.
Have flat, elongated bodies.
Live in the intestine of the animal they infect.
No digestive system, sucks nutrients from their hosts gut.
How to controll tapeworms?
By regular dosing with anti-helminths.
Class Trematoda, flukes. Give info on them.
Parasites of cattle and sheep.
Flat, leaf shaped bodies.
Oral sucker, ventral sucker. To attach themselves to their host.
Found in liver and bile duct.
Cross fertilise and self fertilise of cow, sheep, goat, pigs.
Hermaphrodites.
Stage one of live cycle of liver fluke.
Adult fluke lays eggs in the bile duct of the primary host. Eggs make their way to the intestines. They are excreted.
Stage two of live cycle of liver fluke.
If conditions are fine (temp greater then 10) the eggs hatch larvae known as miracidium. The miracidium must then find a mud snail wihin 24 hrs o ac as a host.
Stage three of live cycle of liver fluke.
The miracidium burrows its way into he snail.
Undergoes a number of larval stages.
Stage four of live cycle of liver fluke.
The miracidia produce a larval stage called a redia, which can produce even more rediae asexually.
Stage five of live cycle of liver fluke.
The rediae develop into cercaria, tadpole like.
Stage six of live cycle of liver fluke.
The cercaria leaves the mud snail. Forms cycts on vegetation.
Stage seven of live cycle of liver fluke.
If the cycts are eaten by an animal, it releases the young fluke which burrows its way to the bile ducts and matures. A mature fluke can produce approx 20,000 eggs per day.
