Identification of mRNAs coding for mammalian-type melanin-concentrating hormone and its receptors in the scalloped hammerhead shark Sphyrna lewini

► Hammerhead shark MCH is composed of 19 amino acids, similarly to the mammalian MCH. ► MCH neurons were distributed in the hypothalamus, but not in the pituitary gland. ► MCH receptor transcripts were detected in the hypothalamus, but not in the skin. ► Hypothalamic MCH mRNA levels were higher in wild-caught sharks than captive sharks.