The blue runner caranx crysos also known as the bluestripe jack egyptian scad hardtail jack or hardnose is a common species of moderately large marine fish classified in the jack family carangidaethe blue runner is distributed across the atlantic ocean ranging from brazil to canada in the western atlantic and from angola to great britain including the mediterranean in the east atlantic. It resembles a fish head with a tail and its main body is flattened laterally. The species is native to tropical and temperate waters around the globe.