Formation of cocoon in earthworm, Biology

Formation of cocoon in earthworm:

In earthworm segments from 14 to 17 are swollen. Skin on these segments is thick and glandular. This is called clitellum.
When ovaries mature, the clitellum secretes a viscous substance in the form of a girdle.
This girdle hardens into a cocoon around the clitellum.
Earthworm wriggles out of the cocoon - cocoon moves anteriorly and the worm moves posteriorly.
Ova are discharged into the cocoon. When the cocoon moves over the spermathecae openings. Spermatozoa received from another animal are stored in the spermathecae are discharged into it.
The cocoon finally comes out of the body and both ends of cocoon get closed.
Fertilization takes place in cocoon. Since fertilization is taking place outside the body, it is external fertilization.
After about 8 to 10 weeks, young earthworms come out of the cocoon.

981_Formation of cocoon in earthworm.png

Related Discussions:- Formation of cocoon in earthworm

What is osmotic diarrhoea, Q. What is Osmotic diarrhoea? This kind of d...

Q. What is Osmotic diarrhoea? This kind of diarrhoea is caused by the presence of osmotically active substances in the intestinal tract, which in turn, favour the drawing of la

Obelia, what are the economic importance of obelia?

what are the economic importance of obelia?

Botulism, B o tu l i s m It is a toxicity in chickens, turkeys, d...

B o tu l i s m It is a toxicity in chickens, turkeys, ducks and other aquatic birds caused by a bacterial toxin produced by anaerobic bacteria Clostridium botulinum mai

Define results of miscellaneous conditions, Results : In the present day,...

Results : In the present day, surgical mortality with or without CABG is repture to be 5-7 per cent. The late survival is 85 per cent, 75 per cent and 65 per cent at 1, 3 and 5

Why do roots of many swamp plants have a special morphology, Why do roots o...

Why do roots of many swamp plants have a special morphology? Swamp and marsh plants usually present supporting roots that ramify from portions of the stem above the ground help

Digestive system in planarias, Q. How are nutrients distributed through the...

Q. How are nutrients distributed through the digestive system in planarias? Planarias have single opening digestive system incomplete with ramifications that transport nutrient

Zoology, Wheel organ of amphioxus.

Wheel organ of amphioxus.

Difference between the following , recptors and effectors

recptors and effectors

How can the excretory system of annelids be described, How can the excretor...

How can the excretory system of annelids be described? In each segment (metamere) of the being a pair of complete excretory structures called metanephridium exists. The metanep

Biota of oceans - ecosystem, Biota of Oceans - Ecosystem Life in the s...

Biota of Oceans - Ecosystem Life in the sea is not particularly abundant, though the diversity of organisms is very high. Almost every major group of animals and every major g

Write Your Message!

Name

Email id

Message

Verfication Code

User Account

All Pages