What are the five characteristics of phylum platyhelminthes?
Platyhelminthes have the following important characteristics: They are triploblastic, acoelomate, and bilaterally symmetrical. They may be free-living or parasites….Unique Characteristics of Platyhelminthes
- Presence of flame cells.
- Ladder-like nervous system.
- Presence of parenchyma in the body cavity.
- Self-fertilization.
What are the classes of platyhelminthes?
The Platyhelminthes includes three classes: the Turbellaria (free-living flatworms), the Trematoda (flukes), and the Cestoda (tapeworms).
What is the larval stage of platyhelminthes?
The larva, called a miricidium hatches and enters the body of a snail. Within the snail’s body cavity it grows into a large sac called a sporocyst, and this then hatches into a further larval stage called the redia.
What are the 3 classes of platyhelminthes flatworms?
Class Turbellaria (turbellarians, flatworms) Class Monogenea (parasitic flukes) Class Trematoda (parasitic flukes) Class Cestoda (tapeworms)
What are the characteristics of Nemathelminthes?
Characteristics of Nematoda
- Their body is bilaterally symmetrical and triploblastic.
- They are cylindrical in shape.
- They exhibit tissue level organization.
- Their body has a cavity or pseudocoelom.
- The alimentary canal is distinct, with the mouth and the anus.
- They are sexually dimorphic.
What is the larval form of Arthropoda?
This larval stage, called a nauplius, is found in barnacles, copepods, penaeid shrimps, and ostracods. It swims by using its jointed appendages that are moved by muscle contraction. These larvae have a nauplier eye, made up of photoreceptor cells that are thought to give rise to the photoreceptors in some adult forms.
What is miracidium larva?
The miracidium is a ciliated, nonfeeding larva (Fig. 9.18). Under favorable conditions, it escapes from the eggshell, usually through the operculum, into the environment. The miracidium is elongated and covered with flattened, ciliated epidermal plates.
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.
Which is also known as Class Phasmidia?
1. class Phasmidia – one of two subgroups of Nematoda used in some classification systems. Phasmidia. Aschelminthes, Nematoda, phylum Aschelminthes, phylum Nematoda – unsegmented worms: roundworms; threadworms; eelworms. class – (biology) a taxonomic group containing one or more orders.
What is the meaning of Nemathelminthes?
Definition of nemathelminth noun. any worm of the phylum Nemathelminthes (now usually broken up into several phyla), including the nematodes and hairworms, having an elongated, unsegmented, cylindrical body.