merogregarina merogregarina merogregarina is a genus of parasitic alveolate in the phylum apicomplexa. species in this genus infect marine invertebrates. merogregarina scientific classification domain: eukaryota (unranked): sar (unranked): alveolata phylum: apicomplexa class: conoidasida subclass: gregarinasina order: archigregarinorida family: selenidioididae genus: merogregarina species merogregarina amaroucii taxonomy this species was described in 1908 by porter. there is one species in this genus - merogregarina amaroucii. description the trophozoites are found in the intestinal lumen. they measure 23-31 microns x 11-15 microns. they are initially ovoid and become vermiform as they mature. the single nucleus lies at the anterior end and has one nucleolus. the trophozoites develop in multinucleated schizonts which give rise to 8-20 merozoites. the merozoites are 5-6 microns x 1 micron. the sporocysts give rise to eight sporozoites. life cycle this species is found in species of the ascidian genus amaroucium. the parasite infects the gastrointestinal tract and is presumably transmitted by the orofaecal route but the details of this mechanism are presently unknown. schizogony is intracellular.