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The direct counting of nematode eggs in feces is the method of choice for yearling animals, whereas in adult animals it may yield high variability due to a cow's immunity and low egg output. [41] Other biochemical methods have been developed to help more accurately diagnose O. ostertagi parasitism. These include the determination of specific ...
Histomonas meleagridis reproduces by binary fission.The free trophozoites are very delicate and can survive only for a few hours in the external environment. However, when they are transmitted between flocks in the eggs of Heterakis gallinarum, a cecal nematode, which in turn can be transmitted by earthworms that ingested the nematode eggs, they gain entry into the nematode eggs.
Nematode sperm is thought to be the only eukaryotic cell without the globular protein G-actin. [49] Eggs may be embryonated or unembryonated when passed by the female, meaning their fertilized eggs may not yet be developed. A few species are known to be ovoviviparous. The eggs are protected by an outer shell, secreted by the uterus.
Root-knot nematode females lay eggs into a gelatinous matrix produced by six rectal glands and secreted before and during egg laying. [19] The matrix initially forms a canal through the outer layers of root tissue and later surrounds the eggs, providing a barrier to water loss by maintaining a high moisture level around the eggs. [20]
The eggs measure 50 to 60 μm by 20 to 30 μm, and have a thick shell flattened on one side. [18] The small size and colourlessness of the eggs make them invisible to the naked eye, except in barely visible clumps of thousands of eggs. Eggs may contain a developing embryo or a fully developed pinworm larva. [18] The larvae grow to 140–150 μm ...
Eggs are excreted in the urine via the renal pelvis. These eggs are oval to cylindrical, yellow-brown, thick-walled, with a rough, knobbed surface, and 71-84 × 45-52 μm in size. [46] The eggs embryonate within two weeks to three months, depending on the ambient temperature, and then become infectious to intermediate hosts. [47]
The animal produces antibodies against the protein which circulate in the blood. When the Barber's pole worm drinks the blood the antibodies attach to its stomach lining, preventing digestion and starving the animal. Following this, the worm produces fewer eggs and eventually dies off. [10]
Nematoida is a clade of pseudocoelomate free living or parasitic animals.It consists of phyla Nematoda and Nematomorpha. [3] [4] The two groups share a number of features in common; the presence of a cloaca in both sexes, aflagellate sperm, and a cuticle made of collagen.