Haplosporida

Haplosporida

A group of Protozoa usually regarded as an order within the class Haplosporea. The chief distinguishing characteristic of the Haplosporida, and the one from which their name is derived, is the production of uninucleate spores that lack polar capsules and polar filaments.

Haplosporida are mainly parasites of invertebrates, such as rotifers, annelids, crustacea, insects, and mollusks, but they also occur in the bodies of Ascidia (tunicates), which are primitive chordates. If the genus Icthyosporidium is properly included in the order, Haplosporida also parasitize fish. One species causes “neon” fish disease.

It is of considerable biological interest that some species of Haplosporida are hyperparasites, that is, parasitic on other parasites. They have been found in gregarines parasitizing annelids, and also in flukes. See Sporozoa

Haplosporida

[¦ha·plō¦spȯr·ə·də]
(invertebrate zoology)
An order of Protozoa in the class Haplosporea distinguished by the production of uninucleate spores that lack both polar capsules and filaments.
References in periodicals archive ?
(Haplosporida, Haplosporidiidae): causative agent of the Delaware Bay oyster epizootic.
Sporulation of Minichinia nelsoni (Haplosporida, Haplosporidiidae) in Crassostrea virginica (Gmelin).
(Haplosporida, Haplosporidiidae) in the Pacific oyster Crassostrea gigas (Thunberg) from the Republic of Korea.
Minchinia nelsoni (Haplosporida) disease syndrome in the American oyster Crassostrea virginica.
(Haplosporida, Haplosporidiidae); causative agent of the Delaware Bay oyster epizootic.
Sporulation of Minchinia nelsoni (Haplosporida, Haplosporiidiidae) in Crassostrea virginica.
(Haplosporida Haplosporidiidae) Causative agent of Delaware Bay oyster epizootic.