Ruminant: Parasite Diagnostic Terms

Single-cell Embryo = Fertilized egg (zygote) prior to cell division.

Morulated = Zygote has gone through a few cell divisions.

Embryonated = Multi-cellular embryo at the tissue / organ development stage, prior to taking final form.

Larvated = Near completion of development, with organism taking final form prior to hatching. May be active within the shell.

Hexacanth = Fully developed larval stage possessing 3 pairs of hooklets. May also be called an Onchosphere. A term specific for eggs of Tapeworms.

Micropyle = Thin area of shell from which sporocysts exit from the oocyst. A term specific for some Coccidians.

Polar cap = Covering over the micropyle of select oocysts. A term specific for some Coccidians.

Operculum = A cap from which worms hatch from the egg. Usually a term specific for Trematodes.

Bipolar Plugs = Thick caps found at the opposite ends of an egg. Usually a term specific for Trichurid and Capillarid nematodes.