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

Define radiological anatomy, Q. Define Radiological anatomy? The border...

Q. Define Radiological anatomy? The borders of the mediastinum on the CXR are defined by the contrast produced by adjacent air filled lung. Postero-Anterior View It in

Endocrine system, INTRODUCTIO N - Endocrinolog y - Study of endocri...

INTRODUCTIO N - Endocrinolog y - Study of endocrine glands, hormones and their effects. Thomas Addison - Father of endocrinology. Described hormonal disease in 1855 kn

Construct cdna samples, Once you have identified a few relevant mRNA specie...

Once you have identified a few relevant mRNA species, you wish to more closely examine their messages by sequencing. You do not have the time to search the genome and isolate the D

Explain texturization - function of protein, Texturization Protei...

Texturization Proteins constitute the basis of structures and texture in several foods, whether these come from living tissue (myofibrills in meat or fish) or from fa

Evaluation of health services, CONCEPT AND MEANING OF EVALUATION: Eval...

CONCEPT AND MEANING OF EVALUATION: Evaluation of programmes is critical for measuring various community health services The ultimate reasons for doing evaluation is to ensure

What are the benefits of soil testing, What are the benefits of Soil testin...

What are the benefits of Soil testing Soil testing is done to assess the nutrient supplying capacity of the soil. The data obtained as a result of testing is useful for recom

What is total cavo pulmonary connections, What is Total Cavo Pulmonary Conn...

What is Total Cavo Pulmonary Connections (TCPC)-Lateral Tunnel Operation? Cardiopulinonary bypass is instituted by cannulation of ascending aorta, SVC innominate vein junction

What is the metagenesis, Q. What is the metagenesis? What are the other nam...

Q. What is the metagenesis? What are the other names of this procedure? Metagenesis is thekind of life cycle in which there are two different forms of individuals of the same s

How many g of h2so4 does contain, How many g of H2SO4 does 600 ml of a 1.2...

How many g of H2SO4 does 600 ml of a 1.2 M solution of H2SO4 contain? Please show all steps.

What is radiographic template, What is Radiographic Template Radiograp...

What is Radiographic Template Radiographic Template : You should always use it while taking a panoramic radiograph of the patient. It is done to counter the effect of magnific

Write Your Message!

Name

Email id

Message

Verfication Code

User Account

All Pages