Panulirus ornatus is an important species of spiny lobster for the aquaculture industry and therefore discovering more about how reproduction is regulated in this species is of great interest. As modulators of many aspects of reproduction, neuropeptides and the enzymes which process them from precursors to mature peptide hormones are integral to this understanding. We produced a multi-tissue transcriptomic library for adult P. ornatus, identifying transcripts for over sixty precursor neuropeptides and for many representatives of neuropeptide processing enzymes. The digital expression pattern of neuropeptide precursor transcripts enabled us to identify an unusual origin for one peptide hormone precursor: adipokinetic hormone/corazonin-like peptide (ACP) in the sperm duct of P. ornatus. Using quantitative PCR and RT-PCR, expression of the ACP precursor mRNA in the medial sperm duct was validated. Interestingly, one of the main enzymes that is likely to be involved with the cleaving of the ACP precursor to produce mature ACP, prohormone convertase 2, was not identified in the sperm duct leading to various possibilities for the role that ACP, or the ACP precursor, may have in regulating reproduction in this species.