Hirudinea

Question 1

Major specie

Characteristics Of Hirudinea
In terms of species
In terms of length
In terms of chaetae & parapodia
In terms of suckers
In terms of segments

Answer 1

Leeches

About 500 species, mostly freshwater parasites
Most leeches are 2-6cm long but one tropical species reaches up to 30cm
The chaetae & parapodia have been lost in almost all forms..
There is always at least one and usually two suckers
The body consists of a definite number of segments which is divided by varying number of annuli

Question 2

Characteristics Of Hirudinea

In terms of coelom
In terms of flattening
In terms of fertilization
In terms of movement
In terms of parasitism

Answer 2

The coelom is reduced and typically is not subdivided by transverse septa
Leeches are usually flattened dorsoventrally like flatworms
They are hermaphroditic (develop a clitellum during the breeding season but are unable to self fertilize so, they cross fertilize)
They move by looping along and many species can swim
They are able to suck blood or other fluids from their hosts (They are ectoparasites of vertebrates)

Question 3

Characteristics Of Hirudinea

In terms of clitellum
In terms of setae & chaetae & coelom
In terms of development, fertilization & habitat

Examples:

Answer 3

They have a clitellum
Setae/Chaetae is absent & coelom is closely packed with connective tissue
Their development is direct, hermaphroditic, terrestrial, freshwater and marine.

E.g: Acanthobdella, Hirudo, Hirudo medicinalis