Dopamine, octopamine, and serotonin are important signal molecules in the nervous systems of all multicellular animals. They are thought to exert hormonal control in a variety of behavioral contexts, including feeding behavior and aggression [60, 61]. Beltz et al. found that the biogenic amines 5-hydroxytryptamine (5-HT) and octopamine (OA) play a significant role in determining mating behavior in the lobster H. americanus [62, 63].