Nema - hair, thread, filament, hence called as hair like organism
Also known as
Nemas- In USA
Eelworm- Europe
Nematode-India
Roundworms- Taxonomist
Based on the feeding habitat they are categorised into
1.Plant feeders- (related to plant pathology)
2.Microbial feeders
3.Miscellaneous feeders
4.Predators
5.Saprophytes
1st Plant parasitic nematode is Anguina tritici - causing earcockle (Wheat) Reported by John Needham (1743)
Definition- Triploblastic, bilaterally symmetrical, unsegmented, Pseudocoelomate & vermiform organism
Body- Elongate, spindle shaped or fusiform, Tapering ends, circular in cross section
Lenth 0.2-11mm width- 0.01-0.5
In few species only of female may be pear, lemon, Reniform, Irregular section
Male and female Nematodes
Morphology
Body consist of 2 tubes
1.Outer body tube
*Cuticle
*Hypodermis
* Muscle layer
2.Inner body tube
*Alimentary canal
Cavity- Pseudocoelome (Not defined epithelium)
Unisexual, bisexual, & Parthenogenitic
Cephallic papillae or setae sensory organs.
Reproductive system
Gonads- pair of tubes
Male- one testis
Gonads- open into cloaca
Spicules are present in cloaca
Female-1 or 2 ovaries ( Gonads)
Which open to centrally located vulva
Excretory System
Extritory pore at pharyngeal region supplied by 2 lateral lines joined a transverse canal
Cuticle / Exoskeleton
Protective and tough flexible
Contain 3 layer- Cortex, matrix & fibre
Composed of lipid, glycoprotein, fibroid, collagen, keratin
Amphid- Pair of chemotactic organs located internally on head
Plasmids - Pair of structures at the tail of class
Secernentia
* Release scented substance
Bursae
In some class like secernentia the body wall around the cloaca are modified into bursa which helps to hold female during copulation as clasping organ
Pseudocoelom / Pseudocoel - maintain turgidity
The space between 2 tubes
*Numerous glands }
*Cellular bodies }----------- floating
*Granular material }
Hypodermis
Cellular tissue layer beneath the cuticle
Metabolically active- Secretion & maintenance cuticle
Muscle layer
Spindle shaped longitudinal muscle attached to hypodermis along its entire length
*Include contractile& non contractile muscle
* Makes synaptic contact with nerve ring
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