An organelle formed by the pellicle of all stages of sporozoan protozoa of the subphylum Apicomplexa and also found in developmental stages that may lack the inner pellicle layer; it is composed of two concentric rings (in transverse section), the inner of which corresponds with an invagination of the outer pellicle membrane. Micorpores thus far observed seem to serve as feeding organelles; their role in nonfeeding developmental forms is unknown. [micro- + G. poros, pore]
