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

Posted Date: 9/3/2012 3:28:37 AM | Location : United States







Related Discussions:- Formation of cocoon in earthworm, Assignment Help, Ask Question on Formation of cocoon in earthworm, Get Answer, Expert's Help, Formation of cocoon in earthworm Discussions

Write discussion on Formation of cocoon in earthworm
Your posts are moderated
Related Questions
Explain process of Fatty acid composition We know fats/oils are made up of fatty acids. The number, position and geometry of double bonds within the fatty acids affect the rate

Fresh Water Water, a universal solvent, invariably contains many soluble salts. In fresh water the total salt content remains under 15 percent. Different types of soluble salts

What is the neuromuscular synapse? Neuromuscular synapse is the structure by which the neural impulse passes from the axon of a motor neuron to the muscle cell. This structure

Q. Can you explain Toxicants in Plant Foods? Several foods, some of which we consume regularly, have toxic compounds in them which are best avoided. These compounds can be prot

Organism:-Fungi  Advantages:- Easy to harvest from culture medium. Texture of the fungi improves the functional properties of proteins. Disdvantages:-

Grouping of Stem Cells: The range of differentiation “Potency” is an important property of Stem cells & serves as the basis for classifying cells as : Totipotent SCs -capa

Define effect of Minerals on athletes? Mineral supplementation, particularly iron in cases of iron deficient athletes is beneficial. Similarly, magnesium and chromium supplemen

Q. Show the Communication process steps? Planning - Set goals. - Make a plan with alternatives. - Allow the counsellee to select a alternative which is feasible.

Q. Defense mechanisms used in Diabetes Mellitus? Defense mechanisms are the strategies to cope with the real situation and to maintain self-image. Healthy persons normally use

Swine-pox Pigs of 2 months of age may be infected with vaccinia either naturally or artificially and show pox lesions on the eyelids, snot, inside the thigh and undersurface of th