Globins are the most common type of oxygen-binding protein in annelids. In this paper, we show that circulating intracellular globin (Alvinella pom-pejanaandGlycera dibranchiata), noncirculating intracellular globin (Areni-cola marina myoglobin) and extracellular globin from various annelids share a similar gene structure, with two conserved introns at canonical positions and .