Earthworm Morphology Short Notes
In this article we will discuss about the earthworm morphology
- Earthworm is burrowing animal usually live inside the upper layer of moist soil
- Earthworm have long segmented cylindrical body
- Body is divisible into dorsal and ventral regions
- Dorsal side has a dark mid line along the longitudinal axis is known as dorsal blood vessels
- Ventral side has prominent genital pores
- Number of segments are 100-120 are called metameres
- First body segment is called the peristomium
- Peristomium possess mouth and fleshy lobe overhanging the mouth is called prostomium
- Last body segment is called the pygidium or anal segment
- 14th, 15th and 16th segments are covered by prominent dark band of glandular tissue called clitellum
- Clitellum divides the body of earthworm in 3 regions
- Pre clitellar region – 1st to 13th segments
- Clitellar region – 14th to 16th segments
- Post clitellar region – 17th and onwards
- All segments except the first, last and clitellum bear S shaped setae, it can be extended or retracted. Their function is locomotion.
Apertures in the body of an earthworm
- Dorsal pores: present after 12 segments except the last segment. Coelomic fluid oozes out from this pore that lubricates the surface of body
- Spermathecal pores: situated ventro-laterally and found in segment 5/6, 6/7, 7/8, 8/9. spermatozoa enter the spermatheca through these pores.
- Female genital pore: present in the 14th segment mid-ventrally. The ova discharged out via the female genital pore
- Male genital pore: situated ventro-laterally in 18th segment. sperm release through this pore.
- Nephridiopores: present in all segments except first two segments. Help for Excretion
- Genital papillae: present in the ventral side of 17 and 19 a pair each. These papillae aids in temporary attachment in course of reproduction
You may also like: –
- Earthworm Morphology Short Notes
- Body Wall of Earthworm Short Notes
- Earthworm Digestive System Short Notes
- Earthworm Circulatory System Short Notes
- Earthworm Nervous System Short Notes
- Earthworm Excretory System Short Notes
- Earthworm Reproductive System Short Notes
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