Trematodes are covered by a tegument, that protects the organism from the environment by providing secretory and absorptive functions. The life cycle of a typical trematode begins with an egg. Some trematode eggs hatch directly in the environment (water), while others are eaten and hatched within a host, typically a mollusc.

Trematodes do not multiply directly in humans, but instead mate and produce large numbers of eggs that pass out of the body in the feces, urine, or sputum. Thus, the intensity of human infection is related largely to the rate of exposure to infective larvae—i.e., to the frequency and extent of contact with water and of consumption of ...

· The eggs of trematodes are ciliated which allows for movement in aquatic environments (to reach the intermediate host). · Cestodes have a tubular morphology and are longer in length while trematodes are smaller with a leaf-like morphology.

The adult parasite in the bird's gut produces eggs and these eventually end up on the ground in the bird's feces. Some eggs may be swallowed by a snail and hatch into larvae . These larvae grow and take on a sac-like appearance.

Trematode eggs are excreted in the stool, urine, or sputum of the definitive host. All flukes require a mollusk as their first intermediate host. The larval stage that escapes from the mollusk may then enter a second intermediate host (fish, crustacean), encyst on vegetation, or penetrate directly into the skin of the definitive host.

2002年4月1日 · For example, most adult trematodes simply release their eggs into the lumen of their definitive host gut; the eggs reach the external environment in the host's feces. When metacercariae mature precociously by progenesis and start producing eggs, they are typically located inside the body cavity of the second intermediate host: there is no easy ...

Trematode eggs are typically voided from the host in the feces; they may also be passed in the urine (Schistosoma haematobium) or in the sputum (P. westermani). After exiting the host, eggs produced by trematodes hatch on contact with fresh water, releasing a ciliated free-swimming form known as a miracidium.

2021年4月14日 · Most trematodes are hermaphroditic, but H americana has 2 sexes. The mature worms live in the mesenteric veins where they mate, and females produce eggs. The eggs migrate to the bowel lumen with the help of proteolytic enzymes and exit the infected dog through the feces (Figure 4). 11,12 The prepatent period is 84 days on average. 12

2024年3月27日 · Diagnosis is made after microscopic demonstration of eggs in the stool (intestinal schistosomiasis; intestinal, liver, and lung fluke infections), sputum (pulmonary paragonimiasis), or urine...

5 天之前 · Digeneans of the family Notocotylidae differ from other digeneans in their peculiar eggs. The eggs feature a pair of long filaments extending from their poles, and their contents differ significantly from what we expect to observe in the eggs of digeneans. Instead of a ciliated miracidium larva, the notocotylid egg contains a tiny few-celled mother sporocyst. This sporocyst infects a snail ...