- 1. A larval form of digenetic trematode (fluke) that develops in the body of its molluscan intermediate host, usually a snail; the s. forms a simple saclike structure with germinal cells that bud off internally and develop into other larval types that continue this process of larval multiplication (considered to be a form of polyembryony). SEE ALSO: miracidium, redia, cercaria. 2. A secondary cyst that develops within the oocyst of Coccidia, a group of sporozoans that includes many of the most important disease agents of domestic animals and fowl; the s. develops from a sporoblast and produces within itself one or several sporozoites, the infective agents for infection and multiplication in the next host. [sporo- + G. kystis, bladder]
* * *spo·ro·cyst -.sist n1) a case or cyst secreted by some sporozoans preliminary to sporogony also a sporozoan encysted in such a case2) a saccular body that is the first asexual reproductive form of a digenetic trematode, develops from a miracidium, and buds off cells from its inner surface which develop into rediae
* * *n.the second-stage larva of a parasitic fluke, found within the tissues of a freshwater snail. A sporocyst develops from a first stage larva (see miracidium) and gives rise either to the next larval stage (see redia) or daughter sporocysts. The latter develop directly into the final larval stage (see cercaria) without the intermediate redia stage.
* * *spo·ro·cyst (sporґo-sist) [sporo- + cyst] 1. any cyst, envelope, or sac containing spores or reproductive cells. a germinal saclike stage in the life cycle of digenetic trematodes produced by metamorphosis of a miracidium and giving rise to rediae. 2. a stage in the life cycle of certain coccidian protozoa contained within an oocyst, produced by a sporoblast, and giving rise to sporozoites.
Medical dictionary. 2011.