关键词: 直翅目, 驼螽科, 庭疾灶螽, 中肠, 马氏管, 组织结构

Abstract: 【Aim】 Taking the cave cricket, Tachycines asynamorus, as an example, this study aims to explore the structural adaptation relationship of digestive system and excretory system of cave crickets to living environment. 【Methods】 The structures of midgut and Malpighian tubules of T. asynamorus were explored by anatomical methods, paraffin section, frozen section and ultrathin section. 【Results】 Three gastric caeca of midgut of T. asynamorus extend forward to enclose a proventriculus. The midgut epithelia consist of regenerative cells, columnar cells, and endocrine cells, with typical niches of regenerative cells. Closed endocrine cells are usually located in the periphery of the niches and a large number of secretory granules are gathered in the basal region of endocrine cells. There are two kinds of large secretory granules in columnar cells, linear clump-like ones and spherical ones with high electron density. In the lumen of the midgut, there is a distinct peritrophic matrix. The base of the midgut is composed by the basal lamina and muscle layer. Malpighian tubules are joined to the digestive tract at the junction of the midgut and the hindgut. The transverse section of the Malpighian tubules contains 3-5 cells. There are a vast number of long microvilli in the apical side of the cells, facing the lumen. Numerous concentrically layered spherites with dense electrons were observed in the cells. In the basal regions of the epithelial cells, there are numerous basement membranes which form membrane labyrinth by infolding. 【Conclusion】In the midgut of T. asynamorus, the linear clump-like secretory granules in columnar cells are wrapped by microfilaments. The endocrine cells from the niche stem cell produce endocrine granules, and then excrete the endocrine granules into the hemocoel. The midgut basal lamina including glycoconjugates and microfilaments develops well and provides support for intestinal peristalsis by supporting midgut epithelial cells. A large number of particles and concentrically layered spherites exist in the Malpighian tubule cells of T. asynamorus, implying their functions of storage and excretion.

Key words: Orthoptera; Rhaphidophoridae; Tachycines asynamorus, midgut, Malpighian tubules; histological structure