The intestinal system of unfed fresh-water mite larvae Limnesia maculata (O.F. Müller, 1776) (Acariformes, Limnesiidae) has been studied with transmission electron microscopy. The intestinal system is composed of the foregut, including the pharynx and the esophagus, the sac-like blind midgut and the excretory organ. The pharynx begins with the mouth covered by the labrum. The pharynx runs along the bottom of the gnathosoma and shows ventral dilators. No valves are expressed between the pharynx and the esophagus. The esophagus possesses strongly plicate walls and, before entering the midgut, passes through the brain. The sac-like midgut does not reveal a well-pronounced lumen, developed epithelium and separate lobes. It consists of the two cell types of endoderm origin mixed in the midgut volume. The first type – the vacuolated cells – does not possess Golgi bodies and lysosomal apparatus and shows electron-lucent vacuoles with a granular inclusion inside. These cells apparently do not take part in digestion of the embryonic yolk. The second type – the non-vacuolated cells – shows both, a well developed Golgi complex and large heterolysosomes, and obviously digests the embryonic yolk. Consequently, they may be attributed as specialized vitellophages. Nevertheless, both cell types may take part in formation of the definitive midgut epithelium. The sac-like thin-walled excretory organ is strongly dilated and contains the embryonic wastes in the form of electron-dense globules and birefringent particles. No muscle envelope surrounds the excretory organ. The embryonic wastes together with wastes accumulated during feeding may be evacuated from the organ only after completion of feeding. The excretory canal on this developmental stage is not connected with the excretory organ. It opens to the outside with a simple slit-like excretory pore. Before feeding, larvae have to pass the process of the post-molt development before their midgut would be ready to receive nutrients.

未喂食淡水螨幼虫Limnesia maculata的肠道系统（OFMüller，1776）（Acariformes，Limnesiidae）已用透射电子显微镜进行了研究。肠道系统由前肠组成，包括咽和食道，囊状盲肠和排泄器官。咽开始于被唇覆盖的嘴。咽部沿着食管的底部延伸，并显示腹侧扩张器。咽和食道之间没有瓣膜。食道的壁具有很强的褶皱，在进入中肠之前会穿过大脑。囊状中肠未显示出发音清晰的管腔，发达的上皮和独立的叶。它由中肠体积中混合的两种内胚层细胞类型组成。第一种类型-空泡化细胞-不具有高尔基体和溶酶体装置，显示出电子透明空泡，内部有颗粒状包裹体。这些细胞显然不参与胚卵黄的消化。第二种类型-非真空细胞-显示发育良好的高尔基复合体和大的溶酶体，并明显消化胚卵黄。因此，它们可被归类为专门的噬菌体。尽管如此，两种细胞类型都可能参与中肠上皮的形成。囊状薄壁排泄器官被强烈扩张，并以电子致密小球和双折射颗粒的形式包含胚胎废物。排泄器官周围没有肌肉包膜。仅在喂养完成后，才可以将胚胎废物与喂养期间积累的废物一起从器官中排出。在这个发育阶段的排泄管不与排泄器官相连。它向外部开放，有一个简单的狭缝状排泄孔。在喂食之前，幼虫必须经过蜕皮后的发育过程，才能使其中肠准备好接受营养。