 The blue stingray ( Dasyatis chrysonota ) of southern Africa has long been regarded as a variant of the common stingray . However , the common stingray lacks the blue markings of the other species and differs in morphological and meristic characters , which led the latter to be definitively recognized as a separate species by Paul Cowley and Leonard Compagno in 1993 . The distinction between this species and the similar Tortonese 's stingray ( D. tortonesei ) of the Mediterranean is poorly understood and may not be valid , requiring further investigation . 
