“…Given its minute size and the need to manually dissect a sufficient amount of starting material, the identification of even a single Daphnia neuropeptide via this strategy would surely have been daunting, as hundreds, and in some cases thousands, of central nervous systems (CNSs) were needed for the biochemical isolation and characterization of individual native peptides from much larger crustaceans (e.g. Torfs et al, 2002). Similarly, the de novo sequencing of peptide precursor protein and receptor genes/transcripts, as well as those encoding the biosynthetic enzymes, transporters and receptors involved in amine, diffusible gas and small molecule transmitter neurotransmission, is time consuming on an individual level, and to achieve full, or at least near complete, coverage for all signaling systems, would at best have been an expensive, labor-intensive, multi-year undertaking.…”