Fine structure of the digestive system of Macrocheles muscaedomesticae (scopoli) (acarina: Mesostigmata)


The fine structure of the digestive system of Macrocheles muscaedomesticae is described. The cuticle-lined foregut consists of a muscular pharynx with a pumping function and an eosphagus which actively transfers food. The midgut consists of a ventriculus and several caecae and is composed of 2 types of cells each with a distinctive ultrastructure. The most common type is composed of small cells which detach from the wall and undergo cytoplasmic degeneration during intracellular digestion. They lack inclusions. Small numbers of giant cells, with large numbers of inclusions are also found in the midgut wall. The midgut lacks a peritrophic membrane. The hindgut consists of a rectal tube and rectal bulb whose epithelia have irregular intercellular spaces and probably have a water absorbing function similar to that of many insects. The hindgut is not lined with cuticle. A somatic muscle system is associated with the pharynx and the anal atrium, while a visceral muscle system is found in the rest of the digestive tube. The gross morphology of the digestive tract corresponds with the Anactinotrichida type. © 1978.

Publication Title

International Journal of Insect Morphology and Embryology