Fingerman, M., W.E. Julian, M.A. Spirtes, and R.M. Kostrzewa (1974) The presence of 5-hydroxytryptamine in the eyestalks and brain of the fiddler crab Uca pugilator, its quantitative modification by pharmacological agents, and possible role as a neurotransmitter in controlling the release of red pigment-dispersing hormone. Comparative and General Pharmacology 5(3–4):299–303.