The Stomodeum ( Greek στόμα stoma , German , mouth ' , or "mouth", "opening" and hodaios = "Path") is a segment of the intestine of arthropods , which comprises the area of the oral cavity and the foregut. Due to its ectodermal origin, like the Proctodaeum, it is lined with a cuticle made of chitin and is skinned accordingly during the moult .
In most arthropods, the stomodaeum consists of the oral cavity and the adjoining esophagus . In this section it can expand with the midgut and, as with many insects, form a goiter , with various arthropods ( swordtails , higher crustaceans , many insects) a gizzard or a suction stomach in spiders . In these structures, complex ridges, braces, teeth, traps or chewing plates can develop from the cuticular lining. In some crustaceans , especially species of woodlice (Isopoda), scissor isopods (Tanaidacea) and Cumacea , the Proctodaeum is greatly elongated and extends almost to the stomadaeum, while the midgut is shifted into the midgut glands.
- Proctodaeum. In: Herder-Lexikon der Biologie. Spektrum Akademischer Verlag, Heidelberg 2003, ISBN 3-8274-0354-5 .
- Hannes Paulus: Euarthropoda, Arthropod, ieS In: W. Westheide, R. Rieger (Ed.): Special Zoology. Part 1: Protozoa and invertebrates. Gustav Fischer, Stuttgart / Jena 1997, ISBN 3-8274-1482-2 , p. 443.