Abstract:Immunohistochemical reactivity against short neuropeptide F (sNPF-ir) was detected in both the brain-subesophageal ganglion (Br-SOG) and midgut epithelial cells of the isopod, Armadillidium vulgare. More than 194 cell bodies showed immunohistochemical reactivity in the brain and SOG. A wide distribution of sNPF-ir occured in the optic lobe (OL; 82 cells), accessory lobe (AL; 56 cells), central body (CB), tritocerebrum (Tr; 18 cells), circumesophageal connective (COMI; 7 cells), and subesophageal mass (SOG; 25 cells), while no sNPF-ir was observed in the deutocerebrum (DC) and pseudofrontal organ (PFO). sNPF-ir was also detected in both paraneuronal cells and stomatogastric nerve elements in the midgut muscle layer. Immunostaining of cells in the Br-SOG and midgut was blocked by preabsorption test. No difference was found in number or distribution of sNPF-ir between males and females. sNPF is both neuropeptide and midgut factors. This wide distribution suggests that sNPF may not only coordinate feeding and digestion in A. vulgare but also support multiple functions.