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Related to Miracidium: sporocyst, cercariae, Metacercariae, rediae


(invertebrate zoology)
The ciliated first larva of a digenetic trematode; forms a sporocyst after penetrating intermediate host tissues.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.



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.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
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.
Symptoms Chinese liver Eggs include fatigue, fluke contain a anorexia, well- jaundice, and developed gastrointestinal miracidium. problems.
Once inside the snail host, each miracidium develops a "sporocyst," which may divide and produce other sporocysts.
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.
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).
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
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.
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.