[1] The family Spirocystidae was created in 1915 by Leger & Duboscq in 1915 for this genus.
The asexual forms, crescentic or spiral shaped, may be found in virtually any tissue of the host.
The multinucleate vermicular meronts are ~35 μm in length and occur in the coelomic cavity and various tissues of the host.
The zygote produces a thick walled oocysts ~35 μm in diameter.
The sporoblasts give rise to a single naked sporozoite with a length of up to 40 μm.