Fig. 1. Schematic drawings showing the stomatogastric nervous system (STNS), stomach, heart and pericardial organs. (A) Location within Cherax destructor. (B) Enlarged view: The STNS consists of four ganglia, the paired commissural ganglia (CoGs), the oesophageal ganglion (OG) and the stomatogastric ganglion (STG), together with their connecting and motor nerves. The STNS is located between the brain and the suboesophageal ganglion (SOG), which are connected by the circumoesophageal connective (coc) surrounding the oesophagus. The post-oesophageal commissure (poc) links both cocs close to the SOG. The STG lies within the ophthalmic artery, which carries haemolymph containing hormones released by the pericardial organs to the brain. Another important neurohaemal organ, the X-organ/sinus gland complex, is located in the eystalks. (C) Schematic diagram of an isolated STNS and the location of nerves discussed in the review. dvn, dorsal ventricular nerve; ion, inferior oesophageal nerve; ivn, inferior ventricular nerve; lvn, lateral ventricular nerve; on, oesophageal nerve; son, superior oesophageal nerve; stn, stomatogastric nerve. Not drawn to scale (modified from Skiebe, 1999).