Gross Morphology, Histology and Ultrastructure of the Nymphal Ileum of Conocephalus (Xiphidion) fuscus fuscus (Fabricius, 1793) (Orthoptera, Tettigoniidae)

Abstract

Objective: The alimentary canal is composed of the foregut, the midgut, and the hindgut in insects. The hindgut is the region where the reabsorption of the water and some ions occur and the feces are generated. The hindgut is generally divided into 3 parts as the ileum, the colon and the rectum in insects. The morphological and fine structures of these parts can be used as the taxonomical character. The aim of this study is to investigate the fine structure and morphology of the ileum in the last instar nymph of Conocephalus (Xiphidion) fuscus fuscus (Fabricius, 1793) (Orthoptera, Tettigoniidae). Materials and Methods: In this study, morphology, histology, and ultrastructure of the ileum in the last instar nymphal C. fuscus fuscus were examined by stereomicroscope, light microscope, scanning electron microscope, and transmission electron microscope. Results: Ileum is a tube-like structure, which is situated between the midgut and the colon. The wall of the ileum is composed of muscle tissue, connective tissue, epithelial tissue, and cuticular intima from the outermost to the innermost. Those singlelayered epithelial cells have globular nuclei, and some granulated endoplasmic reticulum can be observed in photographs. Besides, the regenerative cells groups called regenerative nidi are clear in some basal regions of the epithelial layer. Conclusion: The general morphology and structure of the nymphal ileum in C. fuscus fuscus have some differences with the insects belonging to Orthoptera orders, but its histological, cytological, and fine structure are very alike.