Eyestalk neuropeptides play an important role in regulating wide variety of physiological processes in crustaceans. The neuropeptides belonging to the crustacean hyperglycemic hormone (CHH) family, influence the secretion of ecdysteroids and methyl farnesoate (MF) and in turn regulate molting and reproduction. Using MF secretion by Mandibular organ (MO) as bioassay two peptides with distinctive Mandibular organ-inhibiting hormone (MO-IH) activity was identified. Among these one peptide possesses hyperglycemic activity.