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
What are the three main types of trophic pyramids studied in Ecology? The three kinds of trophic pyramids studied in Ecology are the numeric pyramid, the biomass pyramid and th

Q. Can you explain Salmonellosis Salmonellosis is a common food bome disease all over the world. There are approximately 1600 different strains (sero types) of Salmonell

What is pasteurization of fruit juice?

Explain Composition of Human Milk? Research clearly shows that each type of mammalian milk is unique and consists of a highly complex mixture of organic and inorganic compounds

Define Dietary Management during Surgery? Surgery increases the nutritional demands of the body and can lead to the elicitation of several nutritional deficiencies/imbalance. M

In today's global economy, goods flow from one country to another like never before, allowing the natural capital from one country to be utilized in many other countries. Some have

Q. Percentage ratio of total Solids and Water in honey? Most genuine honeys contain 13-23 per cent of water. The total solids or moisture can be estimated by drying in a vacuu

Give three ways in which a polar bear is adapted to its environment. A polar bear is adapted to its environment by its high ratio of bulk to surface area, a thick water-repelle

Buffalo-pox The disease is caused by an orthopox virus, closely related to the vaccinia virus. It is not clear whether it should be considered a separate virus or not. By RE m

Differance between Descending Thoracic or Abdominal Aneurysm ? Descending Thoracic Aortic and Thoraco-Abdominal Aneurysm :  The approach is through n left postero-lat