Definition
Haplosporidia is a class of parasitic protozoa that primarily infect marine invertebrates, such as mollusks and crustaceans. These parasites are characterized by their simple spore structure, lacking complex internal components found in other spore-forming parasites. Think of Haplosporidia as microscopic invaders that stealthily infect their hosts. They're like secret agents carrying simple disguises rather than elaborate costumes. The infections can cause significant mortality in shellfish populations, impacting aquaculture and marine ecosystems.