melanin

noun

Etymology: From New Latin, from Ancient Greek stem of μέλας (mélas, “black”) + -in; by surface analysis, melan(o)- + -in.

1. Any of a group of naturally occurring dark pigments, especially the pigment found in skin, hair, fur, and feathers.

   “Generally, cephalopod ink includes melanin, enzymes related to melanin production, catecholamines, peptidoglycans, free amino acids and metals (Derby 2014) .”