Acts as a ligand for galanin receptors galr2a and galr2b. Expressed throughout embryogenesis, from the 1 cell stage to 48 hours post fertilization (hpf), with the highest levels of expression at the 1 cell stage (PubMed:30903017). In larvae 7 days post fertilization (dpf), strongly expressed specifically in nerve cells in the preoptic area of the anterior hypothalamus (PubMed:30903017). Not detected in the dorsal habenula (dHb) (PubMed:30903017). Belongs to the spexin family.