title: Plasma melatonin in the neotenic tiger salamander (Ambystoma tigrinum): effects of photoperiod and pinealectomy.
mesh_terms: D000818:Animals; D003624:Darkness; D008027:Light; D008550:Melatonin / Q000097:blood*; D010870:Pineal Gland / Q000502:physiology*; D011863:Radioimmunoassay; D014562:Caudata / Q000502:physiology*
chemical_list: D008550:Melatonin