greg·a·rine 
(grĕgə-rīn′)
(grĕgə-rīn′)n.
Any of various apicomplexan protozoans that are parasitic within the digestive tract and body cavity of invertebrates, including many insects and mollusks.
[From New Latin Gregārīna, type genus, from Latin gregārius, belonging to a flock; see GREGARIOUS.]
grega·rine′, greg′a·rini·an (-rĭnē-ən) adj.