*Zoological name- Pheretima posthuma
*Habitat- burrows and moist soil.
*Nocturnal habit.
*Species- more than thousand.
*Phylum- Annelida.
*life span- 3&1/2 to 10 yrs.
*Cold blooded animal.
Morphology
- Bilaterally symmetrical, cylinde body.
- Length- ~150mm
- Colour-dark brown due to presence of PORPHYRIN pigment.
- Body consist of 100-120 metameres or small ring like segments.
- Inner body is divided by septa,but septal wall is absent in first four segment and between 9th and 10 segment.
- All body segment are alike except first and last segment.
- First body segment consist of prostomium and mouth.
- First body segment is called peristomium.
- Clitellum is a band of glandular tissue which cover 14-16th segment of mature worm.
- 5th-9th segment- spermathecal aperture.
- 14th segment- single female genital pore is present.
- 18th segment- a pair of male genital pores.
- Nephridiopores are present on body surface.
- Setae are present on middle of each segment except first, last and clitellum. it helps in locomotion.
Anatomy
- Epidermis is made up of columnar epithelial cell which contain secretary glands and epidermis is covered by non cellular cutical.
- Alimentary canal runs between first to last segment.
- 1-3 segment- mouth opens into buccal cavity
- 5-7 segment- oesophagus
- 8-9 segment-musculas gizzard( helping in grinding food)
- 9-14 segment- stomach, here calciferous glands present.
- 15th-last segment- intestine.
- 26th segment- intestinal caecae.
- 26-35 segment- typhlosole is an internal median fold.
- closed boold vascular system consist of vesssel, capillary and heart.
- 4th-6th segment- blood glands produces haemoglobin and blood cell.
- Blood cells are phagocytic in nature.
- Respiratory exchange occurs through moist body surface.
- Nepheridia is an excretory organ.
- NEPHERIDIA-Septal nepheridia...15th to last segment,that open into intestine
Integumentary nepheridia...3rd to last,attached to lining of the body.
Pharyngeal nepheridia...present in 4th,5th and 6th segment in pairs.(3pairs)
- Nervous system is represented by ganglia.
- Sensory system doesn't have eyes but posses light and touch sensitive organ.
- Earthworm is a hermaphrodite.
- 10th-11th segment-two pairs of testes and vasa deferentia run upto 18th segment.
- 17th &19th segment- two pairs of accessory gland.
- 18th segment-male genital pore.
- 6-9th segment- four pairs spermathecae, which receive and stores spermatozoa.
- 12&13 segment- 1 pair of ovary.
- 14th segment- female genital pore.
- After mating mature sperm,egg and nutritive fluid are deposited into cocoons, produced by gland cells of clitellum.
- Fertilization and development occurs inside cocoons.
-These cocoons holds worm embryo for 3 weeks and then each cocoons produces 2-12 baby worm.
-No larval stage in earthworm. Development is direct.
*Habitat- burrows and moist soil.
*Nocturnal habit.
*Species- more than thousand.
*Phylum- Annelida.
*life span- 3&1/2 to 10 yrs.
*Cold blooded animal.
Morphology
- Bilaterally symmetrical, cylinde body.
- Length- ~150mm
- Colour-dark brown due to presence of PORPHYRIN pigment.
- Body consist of 100-120 metameres or small ring like segments.
- Inner body is divided by septa,but septal wall is absent in first four segment and between 9th and 10 segment.
- All body segment are alike except first and last segment.
- First body segment consist of prostomium and mouth.
- First body segment is called peristomium.
- Clitellum is a band of glandular tissue which cover 14-16th segment of mature worm.
- 5th-9th segment- spermathecal aperture.
- 18th segment- a pair of male genital pores.
- Nephridiopores are present on body surface.
- Setae are present on middle of each segment except first, last and clitellum. it helps in locomotion.
Anatomy
- Epidermis is made up of columnar epithelial cell which contain secretary glands and epidermis is covered by non cellular cutical.
- Alimentary canal runs between first to last segment.
- 1-3 segment- mouth opens into buccal cavity
- 5-7 segment- oesophagus
- 8-9 segment-musculas gizzard( helping in grinding food)
- 9-14 segment- stomach, here calciferous glands present.
- 15th-last segment- intestine.
- 26th segment- intestinal caecae.
- 26-35 segment- typhlosole is an internal median fold.
- closed boold vascular system consist of vesssel, capillary and heart.
- 4th-6th segment- blood glands produces haemoglobin and blood cell.
- Blood cells are phagocytic in nature.
- Respiratory exchange occurs through moist body surface.
- Nepheridia is an excretory organ.
- NEPHERIDIA-Septal nepheridia...15th to last segment,that open into intestine
Integumentary nepheridia...3rd to last,attached to lining of the body.
Pharyngeal nepheridia...present in 4th,5th and 6th segment in pairs.(3pairs)
- Nervous system is represented by ganglia.
- Sensory system doesn't have eyes but posses light and touch sensitive organ.
- 10th-11th segment-two pairs of testes and vasa deferentia run upto 18th segment.
- 17th &19th segment- two pairs of accessory gland.
- 18th segment-male genital pore.
- 6-9th segment- four pairs spermathecae, which receive and stores spermatozoa.
- 12&13 segment- 1 pair of ovary.
- 14th segment- female genital pore.
- After mating mature sperm,egg and nutritive fluid are deposited into cocoons, produced by gland cells of clitellum.
- Fertilization and development occurs inside cocoons.
-These cocoons holds worm embryo for 3 weeks and then each cocoons produces 2-12 baby worm.
-No larval stage in earthworm. Development is direct.
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