Ultrastructure of Midgut of Scrabeus sacer (Coleoptera:Scrabaeidae)

Abstract
The midgut of the adult Scrabeus sacer was divided into three parts, anterior, middle and posterior midgut. In the anterior part of the midgut, the apical part showed microvilli long and slender. These microvilli appear open in other parts. Numerous organelles appeared, well-developed nucleus mitochondria, rough endoplasmic reticulum. A thin basement membrane was observed and well-developed basal labyrinth. Regenerative cells were observed and well-developed circular muscle fibers. Tracheae and mitochondria were also observed. In the median portion of the midgut, well-developed long and slender microvilli were observed. Polymorphic mitochondria, well-developed nucleus, rough endoplasmic reticulum and other organelles were coming out of the cell to the lumen through the apical part of the middle midgut. A basement membrane, well-developed basal labyrinth, circular muscles, tracheae and vacuoles were observed in the basal part of the median midgut. The rear part of the midgut showed a well-developed brush border of microvilli. Polymorphic mitochondria, rods of bacteria, nucleus and other organelles are projecting in the lumen of the cell. Lateral cell membranes and numerous crescent shape mitochondria were observed in the posterior midgut. Gap junctions were observed in the posterior midgut. A well-developed basal labyrinth was observed enclosing mitochondria and tracheae. Regenerative cells are obvious in the basal part of the posterior region. The rough endoplasmic reticulum is not restricted to a defined part of the cell. No peritrophic membrane was observed throughout the midgut of the adult beetle Scrabeus sacer. Multivesicular bodies were observed in different parts of the midgut.