What are the 7 classes of annelida?

Classification of Annelida

• Polychaeta.
• Oligochaeta.
• Hirudinea.
• Archiannelida.

1. What are the classes of annelids?
2. How many classes belong to annelida?
3. How many species of annelida are there?
4. What is the largest class of annelida?
5. What are the 2 main groups of annelids?
6. What are the two main groups of annelids?
7. What is the difference between Metameres and Septa?
8. What are the characteristics of a Trochophore?
9. Why does earthworm belong to phylum Annelida?
10. Which of the following classes of annelida one pair ovaries and several pair testes are found?
11. Does polychaete have Clitellum?
12. Do leeches have Chaetae?
13. Do all Polychaetes have parapodia?

What are the classes of annelids?

Most authors accept the annelids as having three major classes: Polychaeta, Oligochaeta, and Hirudinea. Older systems would place the polychaetes and oligochaetes under the class Chaetopoda because both groups possess setae.

How many classes belong to annelida?

There are three classes of annelids: Class Polychaeta: marine annelids; Class Oligochaeta: marine, freshwater and terrestrial annelids including earthworms; Class Hirudinea: marine, fresh water and terrestrial leeches.

How many species of annelida are there?

A major invertebrate phylum of the animal kingdom, the annelids number more than 9,000 species distributed among three classes: the marine worms (Polychaeta), which are divided into free-moving and sedentary, or tube-dwelling, forms; the earthworms (Oligochaeta); and the leeches (Hirudinea).

What is the largest class of annelida?

The polychaetes comprise the largest class of annelids with more than 10,000 species, most of them marine.

What are the 2 main groups of annelids?

For the purposes of this concept, we will consider two main classes of annelids: Polychaetae and Clitellata. The Clitellata are characterized by the presence of a specialized reproductive organ called the clitellum.

What are the two main groups of annelids?

Traditionally the annelids have been divided into two major groups, the polychaetes and clitellates.

What is the difference between Metameres and Septa?

What is the difference between metameres and septa? External segments are called metameres and internally, septa, or dividing walls, are located between the segments. ... Annelids are worms with cylindrical bodies segmented both internally and externally, which includes earthworms.

What are the characteristics of a Trochophore?

trochophore, also called trochosphere, small, translucent, free-swimming larva characteristic of marine annelids and most groups of mollusks. Trochophores are spherical or pear-shaped and are girdled by a ring of cilia (minute hairlike structures), the prototroch, that enables them to swim.

Why does earthworm belong to phylum Annelida?

Phylum: Annelida

Annelids are segmented worms. Earthworms belong to this phylum because their bodies are sectioned, creating the ridged or ringed appearance that gives the "ringed worms" of this phylum their name.

Which of the following classes of annelida one pair ovaries and several pair testes are found?

Hirudinaria belongs to Class- Hirudinea. It consists of 11 pairs of testis sacs in segment 12 to 22 and 1 pair of globular ovisacs enclosing coelomic spaces and an ovary in each.

Does polychaete have Clitellum?

Polychaetes are the most diverse group of annelids and most live in the marine environment. They differ from earthworms and leeches in that they have appendages called parapodia and do not possess a clitellum.

Do leeches have Chaetae?

Unlike other annelids, leeches do not have parapodia ('feet') or chaetae (bristles) (except for Acanthobdellida). Leeches usually have three jaws and make a Y-shaped incision. The Australian land leech has only two jaws and makes a V-shaped incision.

Do all Polychaetes have parapodia?

The known species of polychaetes share only a few characteristics. Each has a head, a tail and a segmented body, and typically each body segment has a pair of leg-like parapodia with spiny bristles sticking out. ... Since there is an exception to every rule, some polychaetes have no parapodia at all.