The upcoming discussion will update you about the difference between A. Duodenale and N. Americanus.
Difference # A. Duodenale:
(a) Adult worms:
1. Size:
Adults worms are large in size and are coarser.
2. Anterior end:
Bends in the same direction as the body curvature.
3. Buccal capsule:
It is armed with a pair of chitinous ventro-lateral cutting plates bearing teeth. Two sharp teeth are present at the base of buccal capsule.
4. Copulatory bursa:
The bursa is broad and there is a single dorsal ray and the nearly equal spread of the three lateral rays are distinguishable.
Total number of rays – 13.
The posterior end of male is provided with two spicules which are separate.
5. Posterior end of female:
The female has a pointed posterior end.
6. Vulval opening:
Behind the middle of the ventral side of the body.
(b) Filariform larvae (Third stage larvae):
1. Shape of the head:
Slightly conical in shape.
2. Size:
Shorter than N. americanus and is about 0.5 mm long.
3. Buccal cavity:
Larger lumen is found.
4. Oesophago- intestinal junction:
There is no distinguishable gap between the oesophagus and the intestine.
5. Posterior end of the intestine:
A small refractile body is present.
6. Position of the genital rudiment:
Genital rudiment is noticed behind the point mid-way between the end of the oesophagus and the anus.
7. Cuticular striae
Less visible.
(c) Pathogenicity:
More pathogenic.
Difference # N. Americanus:
1. Size:
Adult worms are smaller in size and are more slender.
2. Anterior end:
Bends in opposite direction to the body curvature.
3. Buccal capsule:
Buccal capsule bears 4 chitinous plates -2 on ventral surface and 2 on the dorsal surface.
4. Copulatory bursa:
The bursa is longer and narrower and it is distinguishable by the split dorsal ray and approximation of two of the lateral rays.
Total number of rays —14.
Two spicules are fused at the tip.
5. Posterior end of female:
There is no caudal spine.
6. Vulval opening:
In front of the middle of the ventral side of the body.
(b) Filariform larvae (Third stage larvae):
1. Shape of the head:
Round in shape.
2. Size:
Larger than A. duodenal and is about 0.75 mm long.
3. Buccal cavity:
Shorter lumen is noticed.
4. Oesophago- intestinal junction:
An apparent gap is noticed between the oesophagus and the intestine.
5. Posterior end of the intestine:
No refractile body is noticed.
6. Position of the genital rudiment:
It is present in front of the point midway between the end of the oesophagus and the anus.
7. Cuticular striae
Distinct visible.
(c) Pathogenicity:
Not so pathogenic.