Talbot Prudence, Clark Wallis H, Lawrence Addison L
Department of Biology, University of Houston, Houston, Texas 77004.
J Morphol. 1972 Dec;138(4):467-485. doi: 10.1002/jmor.1051380407.
The midgut epithelium of larval and early postlarval brown shrimp has been studied with light and electron microscopy. Ultrastructurally the features of the midgut do not change during these stages of development. On the basis of electron density, two epithelial cell types can be distinguished, and these are referred to as light and dark cells. The dark cells contain more rough endoplasmic reticulum and more free ribosomes than the light cells. Mitochondria in the dark cells have a matrix which is less electron dense than the mitochondrial matrix of the light cells. Both cell types have a microvillous border with a surface coat. The microvilli lack microfilaments within their core, and a terminal web is not differentiated in the stages examined. Tubular smooth endoplasmic reticulum is abundant in the basal portions of the cells. Electron dense, membrane bound vesicles are consistently seen in association with the Golgi apparatus, apical cell surface, and gut lumen and therefore are believed to be secretory granules. Cells in the anterior portion of the midgut often contain very large lipid droplets in the cytoplasm.
利用光学显微镜和电子显微镜对幼虫期和幼体后期棕色对虾的中肠上皮进行了研究。在超微结构上，中肠的特征在这些发育阶段没有变化。根据电子密度，可以区分出两种上皮细胞类型，分别称为亮细胞和暗细胞。暗细胞比亮细胞含有更多的粗面内质网和更多的游离核糖体。暗细胞中的线粒体基质电子密度低于亮细胞的线粒体基质。两种细胞类型都有带表面被的微绒毛边界。微绒毛核心内缺乏微丝，在所检查的阶段未分化出终末网。管状滑面内质网在细胞基部丰富。电子密度高、膜结合的囊泡始终与高尔基体、顶端细胞表面和肠腔相关联，因此被认为是分泌颗粒。中肠前部的细胞在细胞质中常含有非常大的脂滴。
