miracidium

[‚mī·rə′sid·ē·əm]

(invertebrate zoology)

The ciliated first larva of a digenetic trematode; forms a sporocyst after penetrating intermediate host tissues.

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Miracidium

the first larva in the development of trematodes, parasitic flatworms. The elongated body is 0.03 to 0.3 mm long and clad in large ciliated cells, which are usually distributed in four to six longitudinal rows. At the anterior of the body open the penetrative glands (a vestige of the intestine that has changed its primary function), whose secretions facilitate implantation of the miracidium in the body of the intermediate host. The organism’s nervous system is represented by the anterior medullary mass of nerve cells. The miracidia of many species have an X-shaped pigmented ocellus in front. The excretory organs are a pair of protonephridia. The body cavity contains germ cells. Miracidia usually emerge from the egg in water, swim for a time, and then implant themselves in the body of an intermediate host (usually a mollusk), where they are transformed into sporocysts.

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References in periodicals archive

mansoni egg contained developed miracidium which was surrounded by eggshell and several vacuolated red blood cells were prominently visible close to it (Fig.

Abbreviation:- A = Apical gland, BV = Blood vessel, G = Penetration gland, GC = Germinal cells, GR = Granuloma, H = Hepatocytes, IUE = Intrauterine eggs, M = Miracidium, NM = Neural mass, RBC = Red blood cells, SI = Sinusoids, W = Worm.

Histomorphological studies of schistosomiasis in the liver of mouse

Symptoms Chinese liver Eggs include fatigue, fluke contain a anorexia, well- jaundice, and developed gastrointestinal miracidium. problems.

Chapter 6 Parasitic zoonoses

Once inside the snail host, each miracidium develops a "sporocyst," which may divide and produce other sporocysts.

Liver flukes

Schistosome eggs aren't operculated and they rupture when entering the water and release miracidium. These miracidium then find a snail host where the infective tercariae are produced.

Worming their way back: forgotten and new helminths continue to become more common in the United States

These eggs are eliminated in the feces and ingested by a suitable land snail (intermediate host) where it passes through larval stages (miracidium, sporocyst, cercariea, and metacercariae).

Gastrointestinal helminth parasitism in fruit-eating bats (Chiroptera, Stenodermatinae) from western Amazonian Brazil

by tranverse septa (56) N atrophy or oral sucker (57) N first larval stage a miracidium (58) La miracidium hatches from egg and swims to snail host

(59) La miracidium with one pair of flame cells (60) La saclike sporocyst stage ("mother sporocyst") in snail

Macroevolutionary patterns of morphological diversification among parasitic fl atworms (platyhelminthes: Cercomeria)

The miracidium within the eggs release proteolytic enzymes that damages the host tissue leading to passing of loose feces with large number of schistosoma ova (Soulsby, 1982).

The eggs, which were mechanically ruptured along its long axis, release a highly motile ciliated miracidium which was measuring approximately 127 [micro]m in length (Fig.

Caprine schistosomiosis and its therapeutic management

Once eggs have reached a suitable body of fresh water, they develop and release a miracidium. It enters an aquatic snail, which acts as first intermediate host.

Emerging foodborne trematodiasis